Section 1: CATTLE

Cattle Questions

CASE 1.1 A dairy cow presents with an extensive subcutaneous swelling in the stifle region of the left leg (1.1a).

1 What is this lesion?

2 What is the likely cause?

3 What action would you take?

CASE 1.2 An aged beef cow treated previously for chronic suppurative pneumonia now presents with weight loss, ventral oedema and diarrhoea. Serum protein analysis reveals hypoproteinaemia caused by marked hypoalbuminaemia; proteinuria is also present. Rectal palpation reveals an enlarged left kidney; transabdominal ultrasonographic examination of the right kidney fails to reveal any other abnormality.

1 What conditions would you consider (most likely first)?

2 How could you confirm your diagnosis?

3 How can the condition be treated/prevented?

CASE 1.3 You are presented with a recumbent 10-day-old beef calf that has been scouring for the past 2 days (1.3a). The calf has not responded to oral rehydration solution administered twice daily and parenteral marbofloxacin administered by the farmer. Clinical examination fails to reveal any significant abnormalities other than abdominal distension detected by succussion and profound weakness. Analysis of blood samples reveals the following results:

Packed cell volume = 0.31 l/l (0.24-0.36) (31%, 24-36); total plasma protein = 68.0 g/l (60-75) (6.8 g/dl, 6-7.5); sodium = 128 mmol/l (128-145) (128 mEq/l,

128-145); potassium = 7.2 mmol/l (3.6-5.6) (7.2 mEq/l, 3.6-5.6); chloride = 105 mmol/l (94-111) (105 mEq/l, 94-111).

1 Comment on any clinically significant abnormalities.

2 What treatment(s) would you administer?

CASE 1.4 You are presented with an aged beef cow in poor body condition (BCS 1.5/5) with a ‘papple-shaped’ abdomen when viewed from behind (1.4). The abdominal distension has not increased much over the past few weeks. The cows in the herd are due to start calving within 3 weeks and are grazing poor pasture and fed barley straw and 1 kg of concentrates. This cow appears otherwise well and came to the feed trough this morning as usual.

1 What conditions would you consider?

2 What action would you take?

CASE 1.5 A farmer feeds a total mixed ration to his dairy cows; the straights are stored on the floor of a large multi-purpose shed (1.5a).

1 List the disease risks, and potential vectors, associated with this method of feed storage.

2 How could these disease risks be reduced?

CASE 1.6 You are called to assist a cow calving on a beef farm. Approaching the calving pens you notice an old wheelbarrow used to store the ‘essentials’ (1.6).

1 Comment on the suitability of antibiotic storage and syringe and needle use/disposal. What are the risks associated with this practice?

2 Comment on the bottle and teat used to ensure passive antibody transfer. Are there any risks you can foresee?

3 Any other comments?

CASE 1.7 You are presented with a non-pregnant beef cow in poor body condition (BCS 1.5/5) with submandibular oedema and what appears to be a distended abdomen.

1 Describe the important findings.

2 What conditions would you consider?

3 What action would you take?

CASE 1.8 A beef farmer reports that several of his fattening cattle are dull, inappetent and scouring (1.8). The cattle were housed 4 weeks ago and the barley component of the ration steadily increased to ad-libitum feeding 2 days ago. When walking, several affected cattle appear weak and often stumble. They have distended abdomens due to an enlarged static rumen; bruxism is frequently heard. Auscultation reveals no rumen motility; succussion reveals tinkling sounds due to the sequestration of fluid and gas. There is profuse very fluid, foetid diarrhoea, which has a sweet-sour odour and contains whole grains.

1 What conditions would you consider (most likely first), and what is the pathogenesis?

2 What action would you take?

CASE 1.9 On a hot summer day you drive past a field with beef cattle standing in surface water draining from a midden (1.9). The cattle co-graze with sheep.

1 List the potential disease risks.

2 What immediate action would you recommend?

1.9

CASE 1.10 A 15-month-old Holstein heifer at pasture with 45 others presents with severe (10/10) lameness of the left hind leg with considerable swelling of the left gluteal region (1.10a). The heifer is so painful that she is unable to walk more than a few paces. Examination in the field reveals a raised rectal temperature of 41.5°C (106.7°F), congested mucous membranes and a crepitant feel over the swollen gluteal region.

1 What conditions would you consider (most likely first)?

2 What treatment would you recommend?

3 What control measures would you recommend?

CASE 1.11 You are presented with a beef bull that is 9/10 lame on the right hind leg.

1 Describe what you will do.

roached-back appearance and an anxious expression. The abdomen is markedly distended and ‘papple-shaped’ (10 to 4 distension; 1.12a). Rectal temperature is normal. Heart rate is 72 beats per minute. The force and rate of rumen contractions

CASE 1.12 A 5-year-old beef bull presents with a 3-month history of increasing abdominal distension and loss of condition (1.12a). The bull’s appetite is poor and there are scant hard faecal balls coated in mucus in the rectum. The bull has a is increased to approximately 3-4 cycles per minute (normal rate is one cycle every 40 seconds or so). The withers pinch test (Williams’ test) is negative. Passage of a stomach tube releases only a small amount of gas.

1 What conditions would you consider (most likely first)?

2 How would you confirm your diagnosis?

3 What actions/treatments would you recommend?

CASE 1.13 A 5-month-old beef calf in a group of 20 presents with free gas bloat (1.13a). The cattle are housed and fed silage plus 2 kg (4.4 lb) of concentrates per day. There is no history of bloat in this group.

1 What are the possible causes?

2 What action would you take?

3 How can you tell when the problem has resolved?

CASE 1.14 A 10-day-old beef calf presents with sudden-onset lethargy with bleeding from both nostrils and prolonged bleeding from a jugular IV injection site (1.14a).

1 What conditions would you consider (most likely first)

2 What treatments would you consider?

3 How would you confirm your diagnosis?

4 What preventive measures could be adopted?

CASE 1.15 You are presented with an aged beef cow with a large 10 cm diameter mass (1.15a) firmly attached to the medial aspect of the third metatarsal bone of the left hind leg. The mass has been slowly increasing in size for the past 2-3 months. The cow is not lame, but there is palpable enlargement of the popliteal lymph node.

1 What conditions would you consider (most likely first)

2 What further examination could you undertake?

3 What action would you take?

CASE 1.16 A 2-year-old Holstein heifer presents with history of poor appetite and low milk yield having calved 6 weeks ago. Rectal temperature is 38.9°C (102°F). Heart rate is 72 beats per minute; respiratory rate is 36 breaths per minute with an abdominal component. Auscultation of the chest reveals no adventitious sounds but the heifer has an occasional soft cough and mucopurulent nasal discharge. Ultrasonography approximately half way up the right chest wall over the sixth intercostal space produces the image shown (1.16a).

1 Describe the important sonographic findings and your interpretation.

2 What pathology does the sonogram represent?

3 What treatment would you give?

CASE 1.17 You are requested to undertake a necropsy of a 5-month-old home­bred Limousin-cross beef calf, housed 2 weeks ago, that died after a short period of marked respiratory distress manifest as an increased respiratory rate with abdominal breathing efforts and open mouth breathing. The calf was one of six that had been treated yesterday by the farmer with tulathromycin. Postmortem examination of the lungs reveals marked anteroventral consolidation but also extensive caudodorsal emphysema/bullae formation (1.17).

1 What condition would you consider the most likely cause?

2 What action should the farmer have taken?

3 What control measures could be adopted for future years?

CASE 1.18 A beef farmer with a spring calving herd reports that approximately 20% of his calves show severe shortening of long bones (1.18a), tendon laxity

and occasionally brachygnathia. This is the first time this problem has been recognised on this farm. No new bulls have been added to the herd recently and the calves are the progeny of cows of all breeds and ages.

1 What is this condition?

2 How can the problem be investigated?

3 What control measures can be introduced?

CASE 1.19 You are presented with a 9-month-old beef heifer that is much smaller than other heifers in the group (170 kg [375 lb] versus 320 kg [700 lb]; [1.19, animal on left]). The calf and her dam were purchased when the calf was approximately 2 weeks old. This is the only animal in the group affected. Clinical examination fails to reveal any significant abnormalities; there is no history of illness for this calf.

1 What conditions would you consider (most likely first)

2 What tests would you undertake?

3 What other clinical problems could be expected?

4 How could this scenario have been prevented?

CASE 1.20 A 4-month-old Charolais beef calf has had difficulty bearing weight on the fore legs for approximately 1 week. The calf appeared normal for the first 3 months of life and is in excellent body condition. The calf spends a lot of time in sternal recumbency and has difficulty raising itself. The calf is bright and alert and propels itself along on its knees using its hind legs (1.20a). There are reduced reflexes and flaccid paralysis of the fore legs and increased reflexes and spastic paralysis of the hind legs.

1 Where is the lesion?

2 What lesion would you suspect (most likely first)?

3 What ancillary tests could you undertake?

4 What is the prognosis?

CASE 1.21 A beef farmer reports that two of 15 young beef calves have a wet lower jaw with drooling of saliva. There is a large firm swelling in one cheek of each of the affected calves (1.21). Digital palpation of the cheek via the mouth reveals loss of mucosa and a necrotic plug of muscle in the centre of the diphtheritic mucosal lesion. There is halitosis and swelling of the drainage submandibular lymph node. Rectal temperature is marginally elevated at 39.2°C (102.6°F).

1 What is the cause (most likely first)?

2 What treatment would you recommend?

3 Are there any control measures?

CASE 1.22 You are called to examine a scouring calf on a beef farm. Walking to the calving pens you observe the calving jack used by the farmer to assist delivery of oversized calves (1.22a). When asked, the farmer states that he assists more than 50% of cows to calve, although many of those cows ‘assisted’ occur late in the evening so that he can go to bed.

1 What are your observations/ comments?

CASE 1.23 During a routine visit to a dairy farm you notice that a large number of cows have large swellings over the lateral aspect of the hock joints (1.23a). The affected cows are not lame.

1 What are these lesions?

2 What is the likely cause?

3 What action should be taken?

CASE 1.24 Following bulling activity yesterday, a farmer comments that one of his dairy cows has developed a ventral depression of the tail head with the hind legs drawn well forward under the body (1.24a). The cow appears to be in considerable discomfort. Clinical examination reveals complete lack of tail tone, a rectum distended with firm faeces and a full urinary bladder extending well forward over the brim of the pelvis.

1 What is the cause of this problem (most likely first)

2 What treatment would you administer?

3 What action would you take?

CASE 1.25 You are presented with a valuable 4-month-old bull calf, which the farmer reports has become increasingly unsteady on its legs over the past month (1.25a). The calf has a good appetite and is growing well. He has a lowered head carriage and a wide-based stance and is ataxic with hypermetria of the fore legs, with these changes more pronounced when he trots. There is normal strength in all four legs. The hind leg ataxia results in the calf occasionally falling over, especially when turning quickly. The calf has a normal menace and pupillary light reflexes in both eyes. No cranial nerve deficits are detected. No other animals in the group show similar clinical signs.

1 What area of the brain could be involved?

2 What conditions would you consider?

3 What tests could be undertaken?

4 What action would you take?

CASE 1.26 A group of housed dairy calves, weaned 3 weeks previously and then mixed together, present with chronic weight loss, poor appetite with chronic faecal staining of the tail and perineum (1.26a). Rectal temperatures are normal.

1 What conditions would you

consider (most likely first)?

2 How would you confirm the

diagnosis?

3 What treatment would you

recommend?

CASE 1.27 A 6-year-old Holstein cow that calved 12 hours earlier is presented in sternal recumbency, profoundly depressed, dehydrated, afebrile (37.8°C [100.1°F]), with toxic mucous membranes, an elevated heart rate of 96 beats per minute and an increased respiratory rate (34 breaths per minute) (1.27a). The cow is too weak to stand. The udder is soft but a pale, serum­like secretion can be drawn from one quarter. There is profuse diarrhoea but no blood is present in the faeces.

1 What diseases would you consider (most likely first)?

2 Which disease(s) is most likely?

3 What treatments would you administer?

4 What control measures could be adopted?

CASE 1.28 You are presented with a 2-week-old Holstein bull calf, which the farmer reports has been unsteady on its legs since birth, which was unassisted. The calf has a good appetite and is growing well. He has a lowered head carriage and a wide-based stance (1.28a). The calf is ataxic with hypermetria of the fore legs, with these changes more pronounced when the calf trots. The ataxia occasionally results

in the calf falling over, especially when

turning quickly in the pen. Fine muscle fasciculations are sometimes present in the neck and head, which become more pronounced during handling and resemble coarse muscle tremors causing vigorous jerking movements of the head. The calf has normal menace and pupillary light responses in both eyes. No cranial nerve deficits are detected.

1 What area of the brain could be involved?

2 What conditions would you consider?

3 What action would you take?

CASE 1.29 While attending to a lame bull, a beef client comments that he has a month- old suckled heifer calf that collapses onto the ground when stressed. This behaviour was first observed soon after birth and has not worsened. When the herd is moved to another field, the affected calf lags behind the others and after 50 metres (55 yards) or so suddenly develops hind leg rigidity, propelling itself forwards with the nose almost touching the ground, and then falls into lateral recumbency (1.29a). There is no seizure activity and the calf stands within 10-20 seconds and walks away, albeit with a stilted gait and low head carriage (1.29b). The affected calf is bright, alert and responsive but appears to have exaggerated double muscling compared with herd mates of similar breeding. The tail is not lifted normally when defaecating/urinating, resulting in faecal and urine contamination of the base and tip of the tail, respectively.

1 What conditions would you consider?

2 What tests could be undertaken?

3 What action would you take?

1.30

CASE 1.30 A beef farmer complains that several of his 30 5-month-old winter- born calves have disappointing growth rates after turnout to permanent pasture 2 months previously (1.30). He believes that there is depigmentation around the ear margins and eyes, giving a ‘spectacle­eye’ appearance in these calves, and there is a sparse hair coat. There is some evidence of diarrhoea but no widening of the epiphyses of the distal leg bones.

1 What conditions would you consider (most likely first)?

2 What samples could you collect?

3 What advice would you offer?

CASE 1.31 You are presented with a stirk with a suspected compressive spinal lesion between T2 and L3 (upper motor neuron signs in both hind legs) and need to collect a CSF sample to aid diagnosis (1.31a).

1 How would you collect a lumbar CSF sample?

CASE 1.32 A 2 year-old Holstein heifer presents with a 10-day history of poor appetite and weight loss (1.32a). The heifer produced a live calf unaided 3 weeks previously but is yielding only 16 litres per day (heifer average = 32 litres 3 weeks after calving). The heifer is dull and depressed. Rectal temperature is 38.9°C (102°F). Ocular and oral mucous membranes appear slightly congested. Heart rate is 72 beats per minute; respiratory rate is 36 breaths per minute with an abdominal component. Auscultation of the chest reveals increased wheezes anteroventrally on both sides. The heifer has an occasional soft cough and mucopurulent nasal discharge. The ruminal contractions are normal, occurring once per minute. The heifer has been treated with marbofloxacin for 5 days prior to examination without apparent improvement.

1 What conditions would you consider (most likely first)?

2 How could you confirm your provisional diagnosis?

3 What treatment would you recommend?

4 What is the prognosis for this heifer?

CASE 1.33 During a routine fertility visit to a dairy herd you are presented with a cow that calved 78 days ago showing recurrent and irregular oestrous activity (nymphomania). The cow has a particularly prominent tail head (1.33a). The farmer describes the cow as ‘cystic’.

1 What condition is the farmer talking about?

2 What causes the abnormal oestrous behaviour?

3 What treatment would you administer?

4 What advice would you offer?

CASE 1.34 You are told by the principal of the practice to dehorn a group of beef heifers intended for breeding (1.34a). Your client has just purchased these cattle because they were cheap. The cattle weigh approximately 350 kg (770 lb).

1 While this barbaric practice is not now as common as 20-30 years ago, what analgesic protocol would you adopt?

CASE 1.35 During late summer a beef cow at pasture presents with severe (10/10) lameness of the right hind leg with marked muscle atrophy over the right hip. The right hind foot is swollen above the coronary band with marked widening of the interdigital space. The farmer reports that the cow has been lame for 4 weeks and failed to improve after a single injection of long-acting oxytetracycline administered using a pole lance 3 weeks ago. A dorsoplantar view of the right hind foot is shown (1.35a).

1 Comment on the significant radiographic abnormalities.

2 What is the likely cause(s) of this condition?

3 What is the likely duration of this condition?

4 Has this cow received appropriate treatment and care?

5 How can this problem be resolved?

CASE 1.36 You are presented with a 2-year-old pedigree beef bull with a 2-day history of drooling saliva and quidding. The bull had been purchased 6 months earlier and is insured for loss of use and mortality/euthanasia for welfare reasons. The farmer noted a large firm swelling of the left mandible and treated the bull with a single injection of long-acting oxytetracycline. The bull is otherwise bright and alert. On clinical examination there is marked enlargement of the horizontal ramus of the left mandible, with surrounding painful soft tissue swelling. There is enlargement of the left submandibular lymph node. A lateral radiograph of the left mandible is shown (1.36).

1 Describe the important features shown.

2 What conditions would you consider (most likely first)?

3 What treatment would you recommend?

CASE 1.37 A 320 kg (700 lb) bulling heifer presents with a 10­day history of poor appetite and weight loss. The heifer is dull and depressed with a rectal temperature of 39.1°C (102.4°F). Ocular and oral mucous membranes appear slightly congested. Heart rate is 72 beats per minute; respiratory rate is 32 breaths per minute with an abdominal component. The heifer has an occasional soft cough and mucopurulent nasal discharge. Auscultation of the chest reveals increased wheezes anteroventrally on both sides. Ruminal contractions are normal, occurring once per minute. The heifer was treated as a calf for suspected respiratory disease with marbofloxacin (for 3 consecutive days on two separate occasions). Ultrasound examination of the chest using a 5 MHz sector scanner positioned on the chest wall 10 cm above the point of the elbow reveals the image shown (1.37a).

1 Describe the sonogram.

2 What conditions would you consider?

3 What treatment would you recommend?

4 What is the prognosis for this heifer?

CASE 1.38 During summer you are presented with a recumbent 6-year-old dairy cow. The cow presented with suspected hypocalcaemia early in the morning having calved unaided during the night. The cow could have been recumbent for up to 8 hours in a sparsely bedded calving pen. The cow was treated with 40% calcium borogluconate (IV and SC) by the farmer for suspected hypocalcaemia, but has not regained its feet (1.38). The cow has cleansed (passed the placenta) and there is no mastitis. The farmer describes the cow as a ‘downer’ and has moved her outdoors using a tractor to a grass paddock.

1 What is the definition of

a downer cow?

2 What is the likely cause?

3 What treatment would

you administer?

4 What is the prognosis

for this cow?

CASE 1.39 A 7-year-old Holstein cow presents with a 2-week history of poor milk yield, reduced appetite, marked weight loss and a painful expression (1.39a). The cow is dull and stands with a roached back and abducts the elbows. There is marked jugular distension. Rectal temperature is 39.1°C (102.4°F). Heart rate is 96 beats per minute and irregular but there are no audible murmurs. Respiratory rate is 36 breaths per minute.

1 What conditions would you consider (most likely first)

2 What treatment would you recommend?

3 What is the prognosis?

CASE 1.40 A beef cow presents dull, anorexic with continuous salivation and staining of the lower jaw. An extended neck and ‘anxious’ expression are present (1.40a). Closer examination of the mouth reveals halitosis and pain on palpation of the pharyngeal region. There has been a rapid loss of body condition and the cow has a gaunt appearance.

1 What conditions would you consider (most likely first)?

2 How would you confirm your diagnosis?

3 What treatment(s) would you administer?

CASE 1.41 You are presented with a 600 kg (1,320 lb) fattening bull that is not eating. The farmer has noted that the bull is slightly stiff when walking and has a swollen scrotum (1.41a). Clinical examination reveals an elevated rectal temperature of 40.1°C (104.2°F) and a hot and painful scrotum, but detailed palpation of the contents is not possible because of the oedematous scrotal skin.

1 What conditions would you consider (most likely first)

2 What further investigations would you undertake?

3 What is the likely cause?

4 What treatment would you administer?

CASE 1.42 At a weekly routine fertility visit to a 600 cow dairy you are presented with a recently-calved 6-year-old Holstein cow that has stopped eating and is yielding only 12 litres per day. The cow had a BCS of 4/5 at calving, suffered from hypocalcaemia and has lost considerable body condition in the past 2 weeks. The cow is dull and appears unsteady on her legs. She has been observed licking at walls, cubicle partitions and her own flanks for long periods of time. Rectal temperature is normal. The cow has a gaunt appearance with sunken sublumbar fossae consistent with a much reduced appetite. The cow is constipated while other cows in the high yielding group have soft faeces. There are high-pitched tinkling sounds in the left flank extending under the rib cage.

1 What conditions would you consider (most likely first)?

2 How could you confirm your diagnosis?

3 What treatment would you administer?

4 How could this condition be prevented?

CASE 1.43 You are presented with a 2-hour-old pedigree bull calf that will not bear weight on the left hind leg. The cow was restrained standing in cattle stocks during delivery of the calf. The calf was in posterior presentation and delivered with considerable difficulty by the farmer using a calving jack. There is considerable swelling proximal to the stifle region.

1 What conditions would you consider?

2 How could you confirm your diagnosis?

3 What is the prognosis?

4 How could this situation have been prevented?

CASE 1.44 Interpret these data compiled from commercial beef herds in the UK.

1 Age at first calving. According to the English Beef and Lamb Executive (EBLEX), the age at calving in beef heifers is approximately 34 months.

2 Calving period. In England, surveys show calving periods in the range of 20-22 weeks for 2010/11. Calving periods for beef suckler herds in Scotland were 14-16 weeks for 2010. The average calving intervals for suckler cows calving in England and Wales in 2010 were broadly similar, ranging from 440 to 446 days.

3 Barren rate. Data from enterprise costing surveys show barren cow rates in the range of 6.3 to 8.1 barren cows per 100 cows exposed to the bull in 2010.

4 Bull infertility. Up to 40% of bulls are subfertile.

CASE 1.45 During late winter a farmer complains that some of his autumn calving beef cows are in poorer body condition than expected and have diarrhoea (1.45a). He has also noted that not as many cows as usual are bulling. The herd is managed outdoors and co-grazes pastures with sheep. The cows are fed ab-libitum good quality big bale silage and 2 kg of barley per head per day. The average

rainfall during the previous summer and autumn was much higher than normal.

1 What conditions would you consider (most likely first)?

2 How would you confirm your diagnosis?

3 What treatment would you administer?

4 What advice would you give to the farmer?

CASE 1.46 You are presented with a recumbent 3-day-old beef calf that has been unable to stand following assisted delivery in anterior presentation when the calf ‘stuck at the hips' (1.46). Clinical examination reveals that the calf is unable to extend the left stifle joint, bear weight and extend the leg; the right leg is less severely affected.

1 What conditions would you consider (most likely first)?

2 What treatment would you administer?

3 How could this problem have been prevented?

CASE 1.47 A 15-month-old pedigree heifer in a group of 15 other heifers at pasture presents with increasing udder development and enlargement of all four teats despite not having been mated (1.47a); transrectal ultrasound examination reveals that the heifer is not pregnant.

1 What is the likely cause?

2 How would confirm your diagnosis?

3 What action could be taken?

CASE 1.48 A 10-month-old heifer presents with severe (8/10) lameness of the right hind leg. The heifer was examined by a colleague 10 days ago after sudden­onset lameness; no cause was found, including detailed examination of the foot, and the animal was treated with meloxicam and amoxicillin/clavulanic acid combination for 4 days without improvement. Clinical examination of the heifer reveals considerable soft tissue swelling immediately proximal to the tibiotarsal joint, but the joint itself is not distended. Radiographs of this region are shown (1.48a, b).

1 Describe the abnormal radiographic findings.

2 What is the likely cause?

3 What action should have been taken at the first veterinary examination?

CASE 1.49 A 15-month-old fattening heifer presents with an extensive swelling over much of the left flank estimated to represent about one-third of the animal’s bodyweight. The swelling appeared suddenly 2 months ago and has increased slightly in size since. The swelling is very firm and the skin is under considerable pressure. The heifer has difficulty rising to her feet and spends most of the time

standing. The heifer is otherwise

healthy and eating well. Antibiotic therapy administered by the farmer has had no effect on the size of the mass. An ultrasonogram of the mass is shown (1.49a).

1 What is this lesion?

2 What is the likely cause?

3 What action should be taken?

CASE 1.50 A 6-year-old beef cow presents with extensive brisket oedema and distended jugular veins. This condition has developed slowly over several months but has become pronounced in the last 2 weeks. Rectal temperature is normal. Heart rate is 100 beats per minute but the heart sounds are muffled on both sides of the chest. Respiratory rate is elevated to 40 breaths per minute with a slight abdominal component. Lung sounds are heard only in the dorsal lung fields.

1 Describe the important features of the sonogram obtained using a 5 MHz sector scanner in the sixth intercostal space approximately half way up the chest wall (1.50a).

2 What conditions would you consider (most likely first)?

3 What treatment would you administer?

l.5la

CASE 1.51 A 3-year-old cow presents with a poor milk yield and reduced appetite. The cow was treated for suspected respiratory disease by the farmer with oxytetracycline, with a short-term response. Today, the farmer is concerned because the cow has a bright red discharge from both nostrils (1.51a). On clinical examination the heifer is bright and alert with a rectal temperature of 39.2°C (102.6°F). Heart rate is 88 beats per minutes with no audible murmur. There are no increased respiratory sounds. Rumen motility is normal.

1 What conditions would you consider (most likely first)?

2 What tests could be undertaken to confirm your provisional diagnosis?

3 What treatment would you administer?

4 What control measures would you recommend?

CASE 1.52 You are called to replace the small intestines herniated through the umbilicus of a beef calf born 1 hour earlier (1.52).

1 What is the prognosis for this calf?

2 What action would you take, including details of your anaesthetic approach?

3 How can this problem be prevented?

CASE 1.53 During late summer you are presented with a recently weaned 9-month-old beef calf that has had an usual gait for the past 3 months. The calf is poorly grown compared with its peers and has a stilted gait on both hind legs. The calf spends a lot of time in sternal recumbency and has great difficulty raising itself. There is no history of a previous disease episode affecting this calf. There are no effusions in any of the palpable joints (stifle joints distally). You suspect a lesion affecting both hips and decide to radiograph the hip joints/pelvis (1.53a).

1 Describe the radiographic findings.

2 What conditions would you consider?

3 What action would you take?

CASE 1.54 During a routine fertility visit to a dairy herd you are presented with a heifer 72 days in milk that has not yet been served. The heifer has hobbles on her hind legs (1.54a).

1 Why would the farmer apply hobbles?

2 Are the hobbles fitted correctly?

3 How long should hobbles remain in place?

4 How could the risk of this problem be reduced?

CASE 1.55 During winter you are presented with a 7-month- old spring-born beef heifer still sucking its dam (1.55a). Since housing the cattle 2 months ago, the farmer has noted that the calf is dull and wanders aimlessly around the pen, often walking into corners, and not reversing out like normal cattle. The calf often holds its head up when wandering around such that the farmer thinks it is blind. Clinical examination reveals absence of menace response in both eyes but normal papillary light reflexes. There are no other cranial nerve defects. The calf had been treated by a practice colleague with vitamin B1 2 weeks earlier but without improvement.

1 What conditions would you consider (most likely first)

2 What tests would you undertake?

3 What treatment would you administer?

CASE 1.56 During summer you are called to attend a recumbent 10-year-old beef suckler cow. The cow is at pasture with a 3-month-old calf at foot. The cow is in lateral recumbency and shows seizure activity (1.56a), which makes further clinical examination difficult. The farmer is anxious that you treat the cow immediately to prevent imminent death.

1 What conditions would you consider (most likely first)?

2 What treatment would you administer immediately?

3 What samples would you collect to confirm your diagnosis?

4 What control measures could be adopted for the rest of the herd?

CASE 1.57 During summer a farmer complains that several cattle at pasture show epiphora with tear­staining of the face, initially serous but becoming increasingly purulent and matting the lashes and hair of the face. On closer examination there is marked conjunctivitis with injected tortuous scleral vessels and hyperaemic conjunctivae. Affected cattle show marked photophobia with blepharospasm (1.57).

1 What conditions would you consider (most likely first)?

2 What treatment would you administer?

3 What action would you take?

CASE 1.58 During late October you are asked to examine a young Charolais bull purchased from a pedigree sale 2 months ago. The bull was introduced into a group of four cull cows 3 weeks ago to make sure he was able to serve normally before being transferred to the main herd. Clinical examination reveals pyrexia (40.4°C [104.7°F]) and purulent bilateral nasal discharges (1.58). The respiratory rate is increased and auscultation of the chest reveals crackles, but these sounds are probably transferred from the upper respiratory tract because transthoracic ultrasonography fails to reveal any abnormality of the visceral pleurae. Visual inspection of the cows in the group reveals no abnormalities.

1 What conditions would you consider (most likely first)?

2 How would you confirm your diagnosis?

3 What treatment(s) would you recommend?

4 What control measures could be adopted for future years?

CASE 1.59 You are presented with a dairy cow with a 2-week history of lethargy, poor appetite and reduced milk yield. The cow now stands with a roached back stance with the neck extended and the head held lowered (1.59a). Rectal temperature is elevated (39.4°C [102.9°F]). Ocular and oral mucous membranes are congested. Heart rate is 92 beats per minute. Respiratory rate is elevated to 44 breaths per minute with an obvious abdominal component. Auscultation of the left chest reveals widespread high-pitched tinkling/splashing sounds two-thirds the way up the chest wall, with normal breath sounds on the right-hand side of the chest. Pinching over the withers elicits a painful expression. Ruminal contractions are reduced in strength and frequency. The farmer is unaware that the dairyman had treated the cow for hypocalcaemia immediately after calving when she was found cast on her back and extremely bloated. The cow responded well to IV calcium borogluconate.

1 What conditions would you consider (most likely first)?

2 What tests would you undertake?

3 What treatment would you recommend?

4 How could this condition have been prevented?

CASE 1.60 A 6-year-old beef cow presents with 2-month history of weight loss and diarrhoea despite anthelmintic treatment by the farmer. The cow calved 1 week ago and her calf is much smaller (27 kg [60 lb]) than the other calves in the group (1.60a).

The cow's rectal temperature is normal. No significant clinical signs are found except for diarrhoea without blood or mucosal casts.

1 What conditions would cause weight loss and diarrhoea (most likely first)?

2 What further tests could be undertaken?

3 Why is the calf much smaller than other calves in the group?

4 What is the prognosis for the calf?

CASE 1.61 You are presented with a 10-year- old Friesian cow that is in very poor condition (BCS 1/5). The cow is yielding only 18 litres per day when normally 40-45 litres per day would be expected 2 weeks after calving. Clinical examination reveals a normal rectal temperature. The cow is slightly constipated. A sweet ketotic smell is obvious on the cow’s breath. The sublumar fossae are markedly sunken (1.61a), indicative of a small rumen and poor appetite over the previous 2-3 days.

Normal rumen movements can be heard caudally in the left sublumbar fossa. On percussion, high-pitched metallic sounds (‘ping, ping, ping’) can be heard high up on the left-hand side of the abdomen under the caudal ribcage. Rectal examination fails to reveal any abnormality. There is no evidence of mastitis or metritis.

1 What is your diagnosis?

2 What other conditions could cause tympany in this area?

3 What action would you take?

4 What treatment(s) would you administer?

CASE 1.62 During winter a beef farmer complains that his bulls are constantly rubbing against gateposts and fences causing extensive hair loss, especially over the shoulder, neck and ears (1.62). The bulls are in excellent body condition. The cows and calves in the same groups are much less affected.

1 What conditions would

you consider?

2 What further tests could be undertaken?

3 What actions/treatments

would you recommend?

4 Are there any consequences

of this problem?

CASE 1.63 A Holstein cow presents with history of poor appetite, poor milk yield and weight loss over several weeks. Antibiotic therapy (5 consecutive days’ penicillin injections) has effected some improvement. Blood samples collected by a colleague reveal a marked neutrophilia with left shift and hypoalbuminaemia (17 g/l [1.7 g/dl]) and hyperglobulinaemia (67 g/l [6.7 g/dl]). Your colleague suspects a focal infection and requests help scanning the cow’s liver (1.63a).

1 Describe the sonogram.

2 What conditions would you consider (most likely first)

3 What treatment would you recommend?

CASE 1.64 During mid summer a beef farmer complains about sudden onset of frequent coughing in a group of cows (1.64) grazing permanent pasture. This pasture has been rented for the first time this year and has been previously grazed by yearling beef cattle. Some cows show an increased respiratory rate at rest with an abdominal component. Clinical examination reveals that the cattle are afebrile.

1 What conditions would you consider (most likely first)?

2 What laboratory tests could be undertaken to confirm your provisional diagnosis?

3 What treatment would you administer?

4 What control measures would you recommend?

CASE 1.65 During summer grazing an adult beef cow presents with sudden­onset profound depression, anorexia and pyrexia (41.5°C [106.0°F]).

There is intense scleral congestion, bilateral keratitis and corneal opacity. There is marked photophobia and blepharospasm. There is copious purulent nasal discharge (1.65). Examination of the mouth reveals halitosisfromanerosivestomatitis.There is crusting of the muzzle and sloughing of the mucosa. There is a generalised peripheral lymphadenopathy. The cow is hyperaesthetic to touch, especially around the poll.

1 What conditions would you consider (most likely first)?

2 How could you confirm your suspicions?

3 What treatment would you administer?

4 List any preventive/control measures.

CASE 1.66 A 4-day-old Charolais-cross beef calf presents in opisthotonus (1.66a) and handling produces paddling movements. The calf was born indoors and transferred to pasture when 36 hours old. Rectal temperature is 39.2°C (102.6°F). The menace response is absent and there is marked episcleral congestion and dorsomedial strabismus. Respiratory rate is increased at 60 breaths per minute. The umbilicus had been treated with strong iodine solution and appears normal. There is no evidence of diarrhoea. The lymph nodes are not enlarged.

1 What conditions would you consider?

2 How could you confirm your diagnosis?

3 What is the likely cause?

4 What treatment(s) would you administer?

5 What recommendations would you offer?

CASE 1.67 A day-old beef calf has been found 10/10 lame on the left hind leg. Radiography confirms a fracture through the distal third metatarsal bone (1.67).

1 How could effective analgesia be achieved?

2 What action would you take?

3 What is the likely prognosis?

CASE 1.68 A 10-year-old beef cow in good condition presents with a 2-week history of a protruding left eye and mucopurulent ocular discharge. The farmer has also noticed a blood-tinged serous discharge from the right nostril.

Clinical examination reveals a normal respiratory rate (24 breaths per minute) but little or no air movement via the left nostril (1.68a). There is swelling of the left maxillary region. The submandibular lymph nodes are normal size. Auscultation of the chest fails to reveal any abnormality. Rectal temperature is normal.

1 What conditions would you consider (most likely first)?

2 What further tests could be undertaken?

3 What action would you take?

CASE 1.69 During summer a 3-month-old beef calf at pasture presents with scant mucohaemorrhagic faeces. The calf shows tenesmus causing temporary rectal prolapse. Mucous membranes are slightly pale and the calf is approximately 7% dehydrated. Rectal temperature is 40.0°C (104°F). There is crusting of the nasal mucosa (1.69a) with oral ulcers, most prominent on the hard palate, which are overlain by necrotic debris. All other calves in the group healthy are growing well.

1 What conditions would you consider (most likely first)?

2 How could you confirm your suspicions?

3 What necropsy findings would confirm your suspicions?

4 List any preventive/control measures.

CASE 1.70 A 6-month-old beef calf presents with a history of poor growth; the calf weighs only 150 kg (330 lb) whereas contemporary animals in the group weigh >280 kg (615 lb). The calf is dull and depressed with a poor appetite. Transthoracic ultrasonography reveals normal lungs. Transabdominal ultrasonography in the right sublumbar fossa fails to immediately identify the right kidney, instead this image (1.70a) is found.

1 Describe the sonogram.

2 What could this structure

represent?

3 What action would you take?

CASE 1.71 A rapidly growing yearling beef bull presents with marked effusion of the tibiotarsal and tarsometatarsal joints of both hind legs (left hock joint shown in 1.71a) 1 month before a major bull breeding sale. The owner reports insidious onset of mild lameness. He considers this normal for all young bulls reared intensively for breeding sales, but had one bull rejected for a similar presentation last year.

1 What conditions would you consider?

2 Is this bull fit for sale as a breeding bull?

3 How could this problem be reduced/ prevented?

CASE 1.72 You are presented with a 2-week-old pedigree beef bull with an umbilical swelling. The swelling is firm, painful and cannot be reduced. The calf has not been sucking well for the past 2 days. Ultrasound examination of the swelling produces this image (1.72a).

1 What are the important sonographic features seen in the sonogram

2 What action would you take?

CASE 1.73 During late summer several 8-month-old dairy-cross heifers present with rapid condition loss and diarrhoea (1.73). The heifers are set-stocked at three animals per hectare on permanent pasture. Clinical examination reveals normal rectal temperatures, absence of either ocular or nasal discharges and no adventitious sounds on auscultation of the chest. The calves were vaccinated against lungworm 6 and 2 weeks before turnout to pasture in the spring.

1 What conditions would you consider (most likely first)

2 What further tests could be undertaken?

3 What treatment(s) should be administered?

4 Could this problem(s) be prevented next year?

CASE 1.74 A beef farmer is experiencing problems with cryptosporidiosis towards the end of a 9-week indoor calving period during the spring. He notices that his neighbour is calving outdoors without such a problem and asks you for advice about whether he should turn all remaining pregnant cows out to pasture.

1 What are the potential benefits and risks?

CASE 1.75 A month-old beef calf presents with severe (10/10) lameness of the right fore leg. The calf had previously been diagnosed with septic pedal arthritis of the lateral claw, which had been amputated through distal P1 10 days previously. Clinical examination reveals swelling and pain associated with P1 of the medial claw. A dorsopalmar radiograph of this region is shown (1.75a).

1 Describe the abnormal radiographic findings.

2 What action should be taken?

CASE 1.76 During summer you are presented with a 6-year-old beef cow with a 3-month history of weight loss and diarrhoea (1.76a) despite flukicide treatment by the farmer. The cow calved 4 months ago and her calf is much smaller than the other calves in the group because of poor milk supply. The cow's rectal temperature is normal. No significant clinical signs are found except for diarrhoea without blood or mucosal casts.

1 What conditions would cause such weight loss and diarrhoea (most likely first)?

2 What further tests could be undertaken?

3 What control measures could be adopted?

1.77

CASE 1.77 During the summer you are presented with a valuable pedigree beef bull at pasture that is slow to move and stands with an arched back. The farmer comments that the bull has shown tenesmus over the past 2 days but passes only mucus (1.77). For the past 3 days the bull has refused the 2 kg (4.4 lb) of concentrates offered daily. The farmer suspected ‘an impaction’ and has stomach- tubed the bull with 50 litres of electrolytes once daily for the past 2 days but without improvement. Rectal temperature is normal. Mucous membranes appear congested. The abdomen is markedly distended but rumen motility is absent. The bull does not dip his back when the withers are pinched. Auscultation of the heart and lungs reveals no abnormality except for an elevated heart rate of 98 beats per minute. No abnormality is felt on rectal palpation. The farmer has treated the bull

with penicillin for the previous 2 days without improvement.

1 What conditions would you consider (most likely first)?

2 What further tests would you undertake?

3 What action would you take?

CASE 1.78 During winter a dairy cow presents with chronic weight loss, poor appetite and reduced milk production. No other cows in the group are affected. This morning, the farmer has noted bright red arterial blood at the cow’s nostrils (1.78a). On clinical examination the cow is dull with a rectal temperature of 39.2°C (102.6°F). Mucous membranes appear normal. Heart rate is 88 beats per minutes with no audible murmur. There are no adventitious lung sounds. Rumen motility is reduced.

1 What conditions would you consider

(most likely first)?

2 How can you confirm your provisional diagnosis?

3 What treatment would you administer?

4 What action would you recommend?

CASE 1.79 You are presented with a valuable beef bull that has been 9/10 lame on the right fore leg for the past 2 months. A professional foot trimmer has attended the bull on two previous occasions but without improvement. The lameness was sudden in onset. On clinical examination the bull adducts the right fore leg and adopts a ‘crossed leg' stance with weight borne on the sound lateral claw. Examination of the bull in a turning foot crate reveals a very thin sole of both claws of the right fore foot. A dorsopalmar radiograph is shown (1.79).

1 What conditions would you consider (most likely first)?

2 What action would you take?

CASE 1.80 A 6-year-old Holstein cow presents with a 2-week history of poor appetite, weight loss and poor milk yield. The cow has a painful facial expression, and walks slowly. There is obvious brisket oedema and distended jugular veins. Rectal temperature is elevated (39.2°C [102.6°F]). Heart rate is 80 beats per minute but the heart sounds are muffled on both sides of the chest. Respiratory rate is elevated to 40 breaths per minute with a slight abdominal component.

1 Describe the important features of the sonogram obtained at the sixth intercostal space using a 5 MHz sector scanner (1.80a).

2 What treatment would you administer?

3 Could this situation have been prevented?

CASE 1.81 A colleague requests an opinion regarding a beef cow that has been off colour for the past 4 days. The cow has not eaten for 3 days and presents with an arched back. There are no rumen contractions, but auscultation of the right sublumbar fossa reveals a large area of high- pitched resonant sounds in the site consistent with a very distended caecum. No abnormality could be

palpated on rectal examination. Rectal temperature is 39.1°C (102.4°F). Heart rate is

90 beats per minute. Your colleague would like to perform an exploratory laparotomy

on the basis that “there is nothing to lose”. You recommend further examination and

this sonogram (1.81a) was obtained with a 5.0 MHz sector transducer connected to the examination took 3 minutes.

a real-time, B-mode ultrasound machine placed in the lower right sublumbar fossa;

1 Describe the important sonographic findings.

2 What further tests might you undertake?

3 What action would you take?

4 Comment on the value of an exploratory laparotomy in this case.

CASE 1.82 A 3-year-old Holstein cow presents with a 4-week history of brisket and submandibular oedema (1.82a). The cow is in the far dry group (cows 8 to 3 weeks pre-partum) at pasture. They are examined every day by the tractor driver, who simply counts the number of cows in the field. On clinical examination the cow is dull and depressed and stands with a roached back with the head lowered. There is marked jugular distension and a jugular pulse. Rectal temperature is 39.1°C (102.4°F). The heart is barely audible, being replaced by high-pitched splashing sounds present on both sides of the chest loudest about half way up the chest wall. Respiratory rate is 40 breaths per minute with normal breath sounds limited to the dorsal lung field.

1 What conditions would you consider

(most likely first)?

2 What treatment would you recommend?

3 What recommendations would you make?

CASE 1.83 You are presented with a dairy cow that is slow to move and stands with an arched back (1.83a). The farmer complains that the cow has reduced her milk yield from 35 litres per day to less than 10 litres per day. The rectal temperature is marginally elevated (39.2°C [102.6°F]). Mucous membranes appear congested. Rumen motility is reduced. The cow does not dip her back when the withers are pinched.

Auscultation of the heart and lungs reveals no abnormality. The farmer has treated the cow with ceftiofur for the previous 3 days without improvement.

1 What conditions would you consider (most likely first)?

2 What furthers tests would you undertake?

3 What treatment would you administer?

4 What action would you take?

CASE 1.84 A 5-year-old cow presents with skin lesions confined to the non­pigmented white areas (1.84). The affected skin is dry and raised at the periphery from normal healthy pigmented skin. The skin of the teats appears dry and ‘papery’. The farmer also reports that this cow often has a red nose during the summer.

1 What conditions would you consider (most likely first)?

2 What are the possible causes?

3 What advice would you offer?

CASE 1.85 While out walking on a summer's afternoon you observe a herd of dairy cows coming in for afternoon milking. Approximately 40% of the herd is either score 2/3 or 3/3 lame (DairyCo lameness scale). One cow lags well behind the remainder of the herd (1.85).

1 List four important observations.

2 What conditions would you consider (most likely first)?

3 What other tests could you employ?

4 What treatment would you administer?

5 What action would you take?

CASE 1.86 A Holstein heifer presents with a history of poor appetite and weight loss. The heifer produced a live calf unaided 3 weeks previously but is yielding only 18 litres per day when the herd average is 32 litres. The heifer is dull and the rectal temperature is 39.2°C (102.6°F). Heart rate is 86 beats per minute. Respiratory rate is 38 breaths per minute. Auscultation of the chest reveals no breath sounds over the right chest and reduced sounds on percussion. The heifer has a soft productive cough. Ruminal contractions are normal, occurring once per minute. The heifer has been treated with marbofloxacin for 3 days prior to examination without apparent improvement. A transthoracic ultrasonogram of the right chest

is shown (1.86a).

1 Describe the sonogram and the likely cause.

2 What treatment(s) would you administer?

3 What changes would you expect with successful treatment?

CASE 1.87 A beef cow presents in sternal recumbency after assisted delivery of dead full­term twins by the farmer. The cow (1.87a) is in much poorer body condition (BCS 1.5/5) than the remainder of the group (appropriate BCS of 2.5-3.0/5). The cow is very dull with little ruminal activity and the faeces are hard, dry and coated in mucus. Mucous membranes are pale yellow. There is submandibular and brisket oedema. There are retained fetal membranes and a foetid vaginal discharge. The udder is flaccid and contains little colostrum.

1 What conditions would you consider (most likely first)?

2 What tests would you undertake?

3 What treatments would you administer?

4 What control measures would you recommend?

CASE 1.88 A dairy farm with an intensive block calving pattern is experiencing pre-weaning calf mortality in excess of 12%, with most losses occurring within the first 5 days after birth (1.88). The cows calve in a large communal area with the calves removed after about 4-6 hours. Calves born between 10 pm and 8 am are removed from their dams after morning milking and transferred to individual pens. All calves are then fed a proprietary milk replacer, with ad-libitum concentrates, until weaning at 6 weeks old.

1 What is the likely cause of such mortality?

2 How would you investigate this problem?

3 What simple practical recommendations would you make?

CASE 1.89 You are presented with a dull dairy cow that calved twins 3 days ago. The cow is yielding only 18 litres per day, has a fever (39.9°C [103.8°F]) and retained fetal membranes (1.89). Mucous membranes are congested and there is reduced ruminal motility. Rectal examination reveals an enlarged uterus. There is profuse diarrhoea without blood or mucosal casts. There is also a foetid watery red-brown vaginal discharge.

1 What conditions would you consider (most likely first)?

2 What treatments would you administer?

3 What follow-up treatment would you recommend?

CASE 1.90 A 6-year-old Limousin beef cow presents with 6-week history of weight loss. The cow calved 6 months ago and is 4 months pregnant. Rectal temperature is marginally elevated (39.2°C [102.6°F]). The ocular and oral mucous membranes are pale. Heart rate is 70 beats per minute. Respiratory rate is 24 breaths per minute with no abnormal sounds detected on auscultation of the chest. The cow has a poor appetite and the rumen is shrunken, giving the abdomen a drawn-up appearance (1.90a); ruminal contractions are reduced in strength and frequency. The cow is passing normal faeces. The cow makes frequent attempts to urinate but only a small amount of urine is voided. The cow resents rectal palpation, which reveals a thickened bladder wall and enlarged ureters.

1 What conditions would you consider (most likely first)?

2 How could you confirm your provisional diagnosis?

3 What is the prognosis?

4 What treatment would you recommend?

CASE 1.91 You are presented with a 2-year-old Holstein heifer that has developed obvious brisket, submandibular and fore leg oedema over the past 2 months. Rectal temperature is normal. The heifer has an increased respiratory rate (44 breaths per minute) with frequent non-productive coughing. Auscultation of the chest reveals reduced audibility of lung sounds and reduced resonance on percussion of the ventral third on both sides of the chest. Heart rate is 90 beats per minute and slightly irregular; the sounds are also reduced in volume. The jugular veins are distended. Transthoracic ultrasonography half way up both sides of the chest reveals the same image (1.91a).

1 Describe the important sonographic findings.

2 What are the possible causes?

3 What action would you take?

CASE 1.92 You are presented with an aged beef cow with a cervicovaginal prolapse (1.92a). The cow calved unaided 10 days previously and passed the placenta within 2 hours.

1 How would you correct this problem?

2 What is your advice regarding the management of this cow?

CASE 1.93 A beef cow with a month-old calf at foot has been unable to fully extend and bear weight on the right fore leg since colliding with a fence during handling through the cattle stocks 2 weeks ago. The cow is otherwise well and eating normally. There is obvious loss of muscle over the scapula with a more prominent spine than on the left side. There is a dropped elbow, flexion of the distal leg joints and scuffing of the hooves as the right leg is moved forward (1.93). The foot is knuckled over at rest. The right prescapular lymph node is not swollen. Muscle tone is reduced but withdrawal reflexes appear normal.

1 What conditions would you consider (most likely first)?

2 What treatment(s) would you administer?

3 What is the prognosis for this cow?

CASE 1.94 You are attending a lame bull on a beef farm and drive past cattle grazing poor quality pasture (1.94).

1 Identify the potentially toxic plant present in the field?

2 What clinical signs might be expected?

3 How is the diagnosis confirmed?

4 What treatment and control measures could be adopted?

CASE 1.95 A farmer reports that two approximately 6-month-old intensively-reared beef bulls have been found with a mid-shaft femoral fracture without apparent cause, necessitating immediate slaughter for welfare reasons. Several other young bulls in this group of 30 are lame with swelling of the carpal and hock joints (1.95a). The cattle are fed ad-libitum cereals with access to barley straw. Clinical examination of two bulls reveals severe lameness with widening of the metaphyses, particularly of the third metacarpal and third metatarsal bones.

1 What conditions would you consider (most likely first)?

2 What further examinations could you undertake to confirm your diagnosis?

3 What treatment would you administer?

CASE 1.96 During winter, several animals in a group of 40 housed 4-6-month- old beef calves present with skin lesions distributed over the whole body, but especially the head and neck (1.96). The lesions are superficial, dry, white, scaly and non-pruritic. The affected skin is not thickened.

1 What conditions would you consider (most likely first)?

2 What further tests could be undertaken?

3 What actions/treatments would you recommend?

4 Are there any special concerns?

CASE 1.97 A 6-year-old dairy cow presents with chronic weight loss and poor production since calving 2 months ago. The cow has an increased respiratory rate of 34 breaths per minute with an increased abdominal component. There are reduced lung sounds in the ventral third of the chest on both sides. Heart rate is slightly muffled and elevated at 88 beats per minute. There is an obvious jugular pulse extending half way up the cow's neck. No other abnormalities are detected on clinical examination. Rectal temperature is normal. Further examination of the chest using a 5 MHz sector scanner on the lower right side reveals this image (1.97a, dorsal to the left).

1 Describe the abnormal findings in the sonogram.

2 What is this lesion?

3 What is the likely cause?

4 What action should be taken?

CASE 1.98 List five biosecurity measures and five biocontainment measures that will reduce the risk of Salmonella dublin infection in a dairy herd.

CASE 1.99 You are presented with a 3-day-old beef calf showing seizure activity (1.99a). The calf was normal for the first 36 hours of life but then appeared dull for about 12 hours and was not sucking. On clinical examination there is marked episcleral injection, toxic mucous membranes and mild/moderate dehydration. There is slight distension of the hock and fetlock joints and the calf's extremities feel cold. Rectal temperature is 37°C (98.6°F). The navel feels normal. Palpation and succussion of the abdomen reveals no fluid distension of the abomasum and no distended small intestines.

1 What conditions would you consider (most likely first)?

2 What is the cause of this problem?

3 What treatment would you administer, and what is the prognosis?

4 What control measures would you implement?

CASE 1.100 A pedigree beef bull calf presents with non-weight-bearing lameness (10/10) of the left hind leg of several months' duration (1.100a). The bull has been attended by a colleague who believes the bull has a septic pedal arthritis, but cannot decide which digit is affected and asks for your opinion. The bull has been treated with amoxicillin plus clavulanic acid for 7 consecutive days, and tilmicosin on two separate occasions; both treatments have failed to effect any improvement. There is marked muscle atrophy over the gluteal region. The popliteal lymph node cannot be palpated. There is marked oedema extending from the coronary band to the mid-third metatarsal region (1.100a). This swelling is very painful and the bull kicks aggressively, preventing detailed palpation of the fetlock joint. There is no evidence of a puncture wound.

1 What action would you take?

CASE 1.101 A beef calf aged 6 months presents with severe lameness (8/10) of the left fore leg of several weeks' duration. The calf was normal for the first 3 months or so, but has failed to grow as well as other calves in the group and is in poor body condition. The calf has been treated by the farmer with amoxicillin plus clavulanic acid administered for 5 days without improvement, and subsequently by a veterinary colleague with marbofloxacin. There is obvious muscle atrophy over the shoulder and the prescapular lymph node is 10 times its normal size. There is firm swelling surrounding the carpus, which is painful on palpation. There is no evidence of a puncture wound. A dorsoventral radiograph of the left carpus is shown (1.101a).

1 Describe the abnormalities present.

2 What action would you take?

3 Are there any specific control measures?

CASE 1.102 You are presented with a 9-month-old beef calf that has become increasingly ‘lame' (1.102a) over the past 4 months such that the right hind foot does not contact the ground. Clinical examination reveals contraction of the gastrocnemius muscle causing gross overextension of the hock such that the affected leg is held caudally 15-20 cm off the ground. There is pronounced circumduction of the leg as the calf struggles to walk.

1 What conditions would you consider (most likely first)?

2 What options would you consider?

3 What control measures could

be implemented?

CASE 1.103 An 8-year-old beef cow in poor condition presents with a 2-week history of weight loss. The farmer had noticed excessive salivation 3 days previously and had instigated daily treatment with penicillin without improvement. Clinical examination reveals tachypnoea (40 breaths per minute) and stertor. Nasal airflow is reduced and the animal breathes through the mouth when stressed. There is marked halitosis. After placing a Drinkwater gag, a 6 ? 3 cm area of ulceration with impacted food material in the centre is visible in the caudal hard palate (1.103a). The submandibular lymph nodes are approximately twice normal size.

1 What conditions would you consider (most likely first)?

2 What further tests could be undertaken?

3 What action would you take?

CASE 1.104 You are presented with an aged beef cow that has been 6/10 lame on the left hind leg for the past few months. There is extensive muscle wastage over the gluteal region (1.104a). Clinical examination reveals marked thickening of the stifle joint capsule and obvious joint effusion. No other joint lesions can be palpated, although assessment of the hip joint proves difficult.

1 What conditions would you consider (most likely first)?

2 What other tests could you employ?

3 What treatment would you administer?

4 What action would you take?

CASE 1.105 A beef bull calf aged 3 months presents with non-weight-bearing lameness (10/10) of the right hind leg of 10 days' duration. The calf has been treated by the farmer with amoxicillin plus clavulanic acid administered for 5 days without improvement. There is marked muscle atrophy over the gluteal region. The popliteal lymph node cannot be palpated. There is swelling (oedema) surrounding the fetlock joint, which is painful on palpation. The surrounding oedema prevents accurate palpation of the fetlock joint and no joint effusion can be appreciated. There is no evidence of a puncture wound. A dorsoplantar radiograph of the right fetlock region is shown (1.105a).

1 Describe the abnormalities present.

2 What action would you take?

3 Are there any specific control measures?

CASE 1.106 At a post-calving check at 21 days you notice a large (30 cm diameter) swelling over the left chest wall of a Holstein cow (1.106, arrow). The swelling is firm, fluid-filled, hot and slightly painful. It does not appear to be attached to the chest wall. No obvious skin puncture wound could be found. The cow is otherwise healthy and milking well.

1 What is the likely cause?

2 What action would you take?

3 How can this problem be prevented?

CASE 1.107 During summer a beef farmer complains that a cow is isolated from the group and is dull and depressed. The cow has a gaunt appearance and is reluctant to walk. There is obvious distension of all four fetlock joints and both hock joints. Rectal temperature is 40.0°C (104°F). Mucous membranes are congested. Rumen contractions are reduced. Respiratory rate is raised to 40 breaths per minute. The cow did not conceive last year and therefore did not calve this spring. Despite not lactating, the right forequarter is enlarged and the teat is very swollen, with flies clustered at the teat orifice (1.107a).

1 What conditions would you consider (most likely first)?

2 What is the cause?

3 What treatments would you administer?

4 What control measures would you recommend?

CASE 1.108 You are presented with a 9-month-old Holstein bull, intensively reared on ad-libitum cereals, that shows moderate (6/10) lameness of the left hind leg. The bull was purchased 1 month previously when the lameness was attributed to digital dermatitis, which was prevalent in the group at that time. The bull failed to improve after a single injection of long- acting oxytetracycline. Clinical examination reveals a discharging sinus over the lateral aspect of the distal leg midway between the coronary band and the fetlock joint. There is also marked swelling immediately above the coronary band (1.108a).

1 What conditions would you consider (most likely first)?

2 What action would you take?

CASE 1.109 You are presented with a severely lame (10/10) beef cow that became suddenly lame 2 weeks ago. The cow was treated with procaine penicillin for 3 consecutive days without improvement. The cow was examined 1 week ago by a colleague and treated with tilmicosin but without improvement. There is now marked swelling and widening of the interdigital space, with extensive tissue necrosis and discharging sinuses above the coronary band of both digits (1.109a, b).

1 What is your diagnosis?

2 How could you confirm your diagnosis?

3 What action would you take?

4 List any management, prevention and control measures.

CASE 1.110 A beef bull calf aged 3 days presents with sudden-onset lameness (8/10) of the right hind leg. The calf was treated by the farmer yesterday with amoxicillin plus clavulanic acid without improvement. There is mild distension of the right stifle joint; no other joint lesions can be palpated. Rectal temperature is normal. There is no umbilical swelling.

1 What action would you take?

2 Are there any specific control measures?

CASE 1.111 You are presented with a 6-year-old beef bull with 3/10 lameness of the right hind leg. The bull has shown intermittently low-grade lameness for about 6 months. There is slight effusion of the tibiotarsal and tarsometatarsal joints of both hind legs but marked bony swelling on the lateral aspect in the region of the tarsometatarsal joint (1.111a). This bony swelling appears smooth and is not painful to the touch. The owner asks your opinion on the future breeding prospects of this bull.

1 What conditions would you consider?

2 What assessment could you undertake?

3 Is this bull fit for future breeding?

4 How could this problem be reduced/prevented?

CASE 1.112 During early summer a beef cow at pasture presents with moderate (6/10) lameness of the right hind leg with muscle atrophy over the right hip. The farmer intends to cull the cow as soon as possible as she is not pregnant and her calf has just been weaned. The right hindfoot is swollen above the coronary band but there is no widening of the interdigital space. The farmer reports that the cow has been slightly lame for several weeks and failed to improve after a single injection of long-acting oxytetracycline. A dorsoplantar view of the right hind foot is shown (1.112).

1 Comment on the significant radiographic abnormalities.

2 What treatment would you administer?

3 How should this problem have been treated when the cow first presented lame?

CASE 1.113 A 2-month- old beef calf presents in opisthotonus (1.113a). The calf was found 2 days ago in lateral recumbency and was treated with penicillin by the farmer without improvement. The calf shows severe muscle rigidity such that the joints cannot be flexed. The calf is afebrile.

1 What conditions would you consider (most likely first)?

2 What laboratory tests could be undertaken to confirm your provisional diagnosis?

3 What treatment would you administer?

4 What control measures would you recommend?

CASE 1.114 A dairy cow presents with a horizontal hoof defect affecting all eight digits (1.114a, b); the cow is not lame.

1 What is this defect?

2 What is the likely cause?

3 What action would you take?

4 Are there any specific control measures?

CASE 1.115 A pedigree beef bull calf aged 3 months presents with severe (9/10) lameness of the right fore leg of 4 weeks' duration. The calf has been treated with at least three courses of antibiotics, including amoxicillin plus clavulanic acid and tilmicosin, without improvement. There is marked muscle atrophy and the spine of the scapula is prominent. The prescapular lymph node is markedly enlarged (four times normal size). There is thickening of the joint capsule of the shoulder joint; no other joints are abnormal on palpation. An oblique radiograph of the right shoulder is shown (1.115a).

1 Describe the abnormalities present.

2 What is the likely cause?

3 What action would you take?

4 Are there any specific control measures?

CASE 1.116 A bright, alert 11-month-old beef stirk presents with a 2-month history of mild bloat and brisket oedema (1.116a). Rectal temperature is normal. The stirk has an increased respiratory rate (30 breaths per minute) and is noted to eructate frequently. Auscultation of the chest fails to reveal any abnormal lung sounds, but there is reduced resonance on percussion of the ventral third of the chest on both sides. The heart is clearly audible with a rate of 72 beats per minute. Rumen motility is normal and the stirk has passed normal faeces. The peripheral

lymph nodes are normal.

1 What conditions would you consider (most likely first)?

2 How could you confirm your diagnosis?

3 What action should you take?

CASE 1.117 You are presented with a 2-hour-old pedigree bull calf unable to bear weight on the left hind leg after forced extraction by the farmer using a calving jack. The cow was restrained in cattle stocks during delivery of the calf. The calf was in posterior presentation. The cow fell down when considerable traction was applied using a calving jack with the calf ‘half way out'. There is considerable swelling distal to the calf's left stifle region.

1 Interpret the radiographic findings (1.117a, b).

2 What is the prognosis?

3 How could this situation have been prevented?

CASE 1.118 Following a difficult calving a beef cow presents with weakness of both hind legs and, most noticeably, increased flexion and knuckling of both hind fetlock joints (1.118).

1 What are the possible causes

(most likely first)?

2 What treatment would you administer?

3 How could this problem have

been avoided?

CASE 1.119 A dairy cow presents with lameness of the right hind foot (scale 3/3; DairyCo scale 0-3, where 3 is severe lameness). The foot has been examined by the farmer on two previous occasions over the past 6 weeks but without improvement. Farm records show that the cow has a toe lesion, possibly a deep white line abscess. The cow has lost considerable body condition and is yielding less than 50% of predicted yield. The foot is raised and, after removing debris from the large cavity previously created by the farmer's foot paring, it is possible to probe bone beneath a small layer of granulation tissue. A dorsoplantar radiograph of the foot is shown (1.119a).

1 Describe the important radiographic findings.

2 What is this defect, and what is the likely cause?

3 What action would you take?

4 Are there any specific control measures?

CASE 1.120 You are presented with a Holstein heifer 5 days after toggling (Grymer/Sterner method) for a LDA. The cow has a poor appetite, a disappointing milk yield (less than 5 litres per day) and has lost considerable weight since the toggling, leading to a very gaunt appearance. The cow stands with an arched back with the head held lowered. Rectal temperature is 39.2°C (102.6°F). Mucous membranes are congested and there is severe dehydration. Respiratory and heart rates are elevated. There are no rumen contractions. Scant mucus-coated faeces are present in the rectum.

1 What conditions would you consider (most likely first)?

2 What laboratory tests could be undertaken to confirm your provisional diagnosis?

3 What treatment would you administer?

4 What is the prognosis?

5 What alternative surgical approach could have been undertaken?

CASE 1.121 You suspect traumatic reticulitis in a beef cow that is dull and inappetent with a static rumen. The cow has been ill for 5 days and unresponsive to an injection of long-acting oxytetracycline administered by the farmer on the second day of illness. Transabdominal ultrasonography using a 5 MHz sector

scanner immediately caudal to the xiphisternum yields this sonogram (1.121a). No reticular contractions are noted during the 2 minutes' ultrasound examination.

1 Describe the sonogram.

2 What is the prognosis for surgery?

3 What action would you take?

4 What control measures could be employed?

CASE 1.122 You are presented with a 16-month-old pedigree beef bull with a large swelling around the prepuce (1.122a). The swelling has gradually increased in size over the past 3 months. The swelling is very firm and the skin is under considerable pressure. No skin puncture wounds can be found. The bull is otherwise healthy and eating well; urination is not affected (1.122a). Antibiotic therapy administered by the farmer about 2 months ago initially caused reduction of the mass, but it is now larger than ever.

1 What is the likely cause?

2 What action would you

take?

CASE 1.123 An 8-month-old steer presents with a head tilt towards the left side and drooping of the left ear and left upper eyelid (ptosis) (1.123). There is normal cheek muscle tone. The steer is bright and alert but appears unsteady when trotting out of the cattle stocks. Rectal temperature is normal.

1 What conditions would you consider (most likely first)

2 What is the likely cause?

3 What treatment would you administer?

4 What is the prognosis for this case?

CASE 1.124 You are presented with a young beef cow that calved some hours ago and has just been found with a uterine prolapse (1.124a). The fetal membranes are not attached.

1 How would you correct this problem?

2 What treatments will you

administer?

CASE 1.125 When loading cattle for transport to the slaughter plant a beef farmer notices a swollen scrotum in one of the steers. The steer was purchased 6 months ago and now weighs 800 kg (1,760 lb) and has been growing at a similar rate to its peers. The farmer has not

noted any illness but is concerned

because the animal has been consigned as a steer and will be downgraded as a bull, incurring considerable financial penalty. Rectal temperature is 38.6°C (101.5°F). The scrotum is approximately 25 cm in diameter and is soft on palpation and feels fluid-filled rather than containing fat. No testicles can be palpated. The scrotum is neither hot nor painful. Ultrasound examination of both sides of the scrotum yields the same sonographic findings (1.125).

1 Describe the important sonographic findings.

2 What conditions would you consider (most likely first)

3 What further investigations would you undertake?

CASE 1.126 When loading four 13-month-old intensively- reared beef bulls for transport to the slaughter plant, a farmer notes that one of the bulls (1.126, arrow) appears blind and walks into gates and other obstacles. The cattle are in excellent body condition and have grown at more than 1.4 kg/day. The cattle are fed ad-libitum cereals with access to barley straw. Clinical examination of two bulls reveals bilateral lack of menace response and papillary light reflexes. Inspection of other groups fails to reveal any abnormal behaviour or lameness.

1 What conditions would you consider (most likely first)?

2 What further examinations could you undertake to confirm your diagnosis?

3 What treatment would you administer?

4 What other problems might be expected?

CASE 1.1

1 What is this lesion? A large subcutaneous abscess.

2 What is the likely cause? There are no obvious skin puncture wounds. A contaminated IM injection into the gluteal region, which has tracked distally, is

likely.

3 What action would you take? Lance the abscess (1.1b) near its ventral margin to ensure complete drainage. The abscess cavity should be irrigated with very dilute povidone-iodine daily for the next few days. Parenteral antibiotic therapy is not necessary. Check whether the cow was injected IM 2-3 months ago and review injection technique where necessary.

CASE 1.2

1 What conditions would you consider (most likely first)? Amyloidosis (secondary to chronic pneumonia); right-sided heart failure; chronic liver pathology such as chronic severe fasciolosis; pyelonephritis; paratuberculosis; endocarditis.

Extracellular deposition of amyloid (abnormal deposits of glycoprotein) occurs mainly in the kidney, but also in the gut, liver, adrenal gland, spleen, and other tissues. Both primary and secondary forms of amyloidosis exist. Primary amyloidosis is likely an immune-mediated or metabolic storage disease, whereas secondary amyloidosis has been associated with chronic infections in various organ systems (in this case chronic suppurative pneumonia).

2 How could you confirm your diagnosis? Renal biopsy is rarely indicated. The poor condition of cows at presentation means that most are culled and the diagnosis confirmed at necropsy (1.2).

3 How can the condition be treated/prevented? There is no effective treatment as the condition is irreversible. Early treatment of chronic infection may reduce the risk of secondary amyloidosis, but the condition is uncommon and secondary in clinical significance to the primary lesion.

CASE 1.3

1 Comment on any clinically significant abnormalities. The calf does not appear dehydrated. The total plasma protein concentration is consistent with adequate passive antibody transfer (colostrum ingestion). The sodium and chloride concentrations are normal. The very low bicarbonate concentration and pH value indicate metabolic acidosis probably as a consequence of diarrhoea and loss of bicarbonate/production of organic acids from secondary milk fermentation in large intestine. The calf is hyperkalaemic following compensatory exchange of hydrogen ions for intracellular potassium ions, although there may be whole body depletion of potassium.

2 What treatment(s) would you administer? Treatment must correct the acidosis. Total base deficit (or negative base excess) is calculated as:

base deficit ? bicarbonate space (ECF) ? dehydrated calf weight

= 20 ? (0.5) ? 40 = 400 mmol bicarbonate

ECF = extracellular fluid volume 32-48 g of sodium bicarbonate yielding 400-600 mmol can be added to 3 litres of isotonic saline and administered over 3 hours, with the first litre given over 20 minutes or so. There is a marked improvement within this time period (1.3b). The higher bicarbonate content takes into account potential underestimation of the base deficit and ongoing losses.

There is debate whether follow­up fluids should comprise a high alkalinising oral rehydration solution (ORS) because the severe acidosis has already been corrected by IV bicarbonate administration. One litre of milk should be alternated with ORS to prevent starvation, because the ORS has a low energy content. There is no justification for antibiotic administration unless there is evidence of focal bacterial infection such as omphalophlebitis or polyarthritis.

Scouring was the most common disease reported in young calves and the greatest single cause of death in the UK. Between 2003 and 2012 around 10,000 faecal samples from neonatal calves with diarrhoea were tested. A diagnosis was reached in approximately 75% of submissions with isolation rates of rotavirus (42%), cryptosporidiosis (40%), bovine coronavirus (9%) and Colibacillosis (8%).

CASE 1.4

1 What conditions would you consider? Advanced (possible twin pregnancy) in an old cow; distended rumen due to poor fibrous diet and advanced pregnancy; hydrallantois; vagus indigestion; ascites (right-sided heart failure); hydramnion.

This is probably a twin pregnancy in an old cow coupled with a high fibre diet with inadequate supplementary feeding. Hydrallantois is caused by abnormal placental function with severe abdominal distension caused by the massive accumulation of allantoic fluid (up to 250 litres) that occurs over a short period during the last trimester.

2 What action would you take? Recommend replacing barley straw with grass silage or increasing concentrate feeding to prevent further loss of the cow's body condition and to ensure sufficient colostrum accumulation at calving. Energy requirements for dam maintenance and advanced pregnancy are approximately 80-90 MJ/day, typically afforded by ad-libitum good quality silage and 2-3 kg (4.4-6.6 lb) of barley per day. If straw is fed, this should be supplemented with urea or other protein source to improve intake. Failure to feed adequate energy levels may lead to starvation ketosis (pregnancy toxaemia) in cattle carrying twins.

Live twin calves were born 14 days later.

CASE 1.5

1 List the disease risks, and potential vectors, associated with this method of feed storage. A range of Salmonella species transmitted by wild birds; tuberculosis transmitted by badgers; paratuberculosis transmitted to feed from vehicle wheels,

boots, etc; Neospora caninum transmitted by dogs and foxes; botulism following the death of wild birds; mycotoxicosis from mouldy grain and wet storage conditions.

2 How could these disease risks be reduced? The building should be vermin proof. Doors must be kept closed whenever access is not required, otherwise there is no advantage of having doors. Storage bins (1.5b) should be used wherever possible.

CASE 1.6

1 Comment on the suitability of antibiotic storage and syringe and needle use/disposal. What are the risks associated with this practice? Needles and syringes are designed for single use, although farmers often use them on multiple occasions (there are no new syringes/needles on view). Several antibiotics, including the penicillin preparation in this situation, require storage between 2 and 8°C (35.6 and 46.4°F) (in a refrigerator for most months of the year). Exposure to high environmental temperatures could adversely affect drug efficacy. There is increased risk of contaminated injection sites, with dirty needles/syringes leading to abscesses/cellulitis. There is no sharps disposable receptacle. A 16 gauge needle is not suitable for injecting a cow; an 18 gauge needle would be more appropriate.

2 Comment on the bottle and teat used to ensure passive antibody transfer. Are there any risks you can foresee? It is good practice to encourage the calf to suck colostrum rather than use an oesophageal feeder, but the bottle and teat are filthy. As well as colostrum, the calf is likely to ingest bacteria contaminating the teat and bottle. Calf diphtheria could result from repeated use of a contaminated teat.

3 Any other comments? There is an antibiotic aerosol can in the wheelbarrow presumably to spray the umbilicus of newborn calves; however, there is also a spray bottle, but the contents do not look like strong veterinary iodine. A teat dip bottle may be easier to disinfect the umbilical remnant.

CASE 1.7

1 Describe the important findings. There is a large amount of free fluid within the abdominal cavity, with dorsal displacement of viscera including the liver (1.7b). There is no fibrin present, therefore the fluid is likely to be a transudate. The liver has very rounded margins consistent with chronic venous congestion (nutmeg liver).

Amyloidosis could also explain the hepatomegaly and ascites, but is uncommon in cattle.

2 What conditions would you consider? Ascites as a consequence of right-sided heart failure or hypoproteinaemia (hypoalbuminaemia). Causes of right-sided heart failure could include: chronic respiratory disease such as chronic suppurative pneumonia and diffuse fibrosing alveolitis; mediastinal mass such as thymic lymphosarcoma or abscess; endocarditis; pericarditis; dilated cardiomyopathy (DCM). Causes of hypoalbuminaemia could include: chronic fasciolosis; amyloidosis; pyelonephritis; paratuberculosis; gut tumour (uncommon in cattle compared with sheep).

3 What action would you take? Careful auscultation of the chest would detect septic pericarditis, but there may be no audible murmur in cattle with endocarditis and DCM. Transthoracic ultrasonography to check for pleural effusion and superficial lung pathology. Ultrasonographic examination of heart valves. Serum protein analysis. Sedimentation test for fluke eggs in faeces. Transabdominal examination of the right kidney.

Any action would be based on the findings of these examinations. Vegetative endocarditis of the tricuspid valve was confirmed in this cow.

CASE 1.8

1 What conditions would you consider (most likely first), and what is the pathogenesis? Barley poisoning/ruminal acidosis; salmonellosis. The sudden and unaccustomed ingestion and fermentation of large quantities of carbohydrate-rich feeds results in increased lactic acid production accompanied by a fall in rumen pH, which kills many cellulolytic bacteria and protozoa. Acid-tolerant bacteria such as Streptococcus bovis survive, producing more lactic acid. There is a marked increase in rumen liquor osmolarity, with fluid drawn in from the extracellular space causing dehydration. Low rumen pH reduces motility, causing stasis and mild bloat. Lactate is absorbed into the circulation, leading to the development of a metabolic acidosis. This metabolic crisis is further compounded by toxin absorption through the compromised rumen mucosa.

2 What action would you take? In most situations therapy is restricted to oral fluids, IV multivitamin preparations and antibiotic therapy. Proprietary antacid products contain 220 g sodium bicarbonate, 110 g magnesium oxide and 40 g yeast cell extract diluted in 20 litres for a cow. Antacid drenches, including 500 g of magnesium hydroxide/450 kg, are also recommended to counter the acidosis. Penicillin injections are given daily for up to 10 days in severely affected cattle to counter potential bacteraemia via the hepatic portal vein.

Intravenous fluids should contain bicarbonate, and in an emergency situation it would be safe to administer 10 mmol/l of bicarbonate over 2-3 hours and monitor progress. In practical situations: 16 g of sodium bicarbonate = 200 mmol of bicarbonate, therefore a 320 kg heifer estimated to be 7% dehydrated would require:

Estimated base deficit ? dehydrated body weight ? extracellular fluid volume

(i.e. 10 ? 300 ? 0.3)

= 900 mmol of bicarbonate

Thus 72 g of sodium bicarbonate in 5 litres of saline would approximate a 10 mmol/l base deficit in a 320 kg animal.

Siphoning off ruminal contents (rumen lavage) is described. Large volumes of warm tap water are repeatedly forced down a very wide bore stomach tube, and are then siphoned off. A rumenotomy to remove the rumen contents using a siphon can be attempted, but considerable care is needed to prevent leakage into the abdominal cavity during surgery because affected cattle are recumbent, and it is usually not possible to exteriorise much of the rumen wall due to the large fluid contents.

Management/prevention/control measures: grain/concentrate feeding must be gradually increased over a minimum of 6 weeks before ad-libitum feeding. Allow more than 10% of the diet as good quality roughage.

CASE 1.9

1 List the potential disease risks. Coccidiosis in calves (Eimeria alabamensis); leptospirosis; S. typhimurium and S. dublin; exotic serotypes from wildlife/ vermin; cryptosporidiosis (calves); paratuberculosis (calves infected from midden); abortion caused by Neospora caninum if the midden is used as a latrine by dogs/foxes; nitrate poisoning where surface water drains grassland area recently fertilised; Mycobacterium tuberculosis (infected cattle/badgers using midden as a latrine).

2 What immediate action would you recommend? The surface water must be fenced off immediately and mains water supply established. Livestock should not have access to a midden.

CASE 1.10

1 What conditions would you consider (most likely first)? Include: blackleg (clostridial myositis); femoral fracture; cellulitis/penetration wound; tetanus.

2 What treatment would you recommend? There is no effective treatment for blackleg when the condition is so far advanced and the heifer should be euthanased for welfare reasons. Treatment could be attempted with penicillin and supportive therapy such as oral fluids and an IV NSAID injection, but subsequent necropsy examination in this case revealed that this would not have worked and only have prolonged the animal's suffering, whereby the musculature is dry and dark purple with numerous gas pockets (1.10b). The lungs are congested and oedematous. Recent earth works with piles of excavated soil in the field could have been the source of the clostridia, with trauma to the musculature during bulling behaviour providing an anaerobic site for bacterial multiplication.

3 What control measures would you recommend? The farmer was advised to vaccinate the remaining cattle against Clostridium chauvoei (blackleg) immediately. In addition, all cattle were injected with procaine penicillin at the time of vaccination to prevent the handling procedure from precipitating further cases. The second blackleg vaccine was given 2 weeks later. No further losses resulted in this group. Blackleg vaccine is cheap and a valuable insurance policy if losses from blackleg have previously occurred on the farm.

CASE 1.11

1 Describe what you will do? The bull’s gait indicates a lesion affecting the lateral claw. The most likely lesion is a white line abscess, which occurs most commonly in the abaxial white line towards the sole. An abscess of the sole is also possible. Sole ulcers and digital dermatitis are uncommon in beef cattle and would be obvious on close inspection of the soles and bulbs of the heel, respectively.

The overgrown wall horn covering the sole is quickly removed using a hoof knife and the white line searched for the presence of any penetrating small sharp stones/ black marks. Where present, the white line abscess ascends towards the coronary band, therefore the wall rather than the sole should be removed. There should be no damage to the corium and therefore no bleeding when paring the foot. A considerable amount of the wall horn has been removed to release the abscess (1.11b), which was under considerable pressure. There is no need to bandage the foot in this case because the corium has not been damaged. There is no requirement to administer antibiotics.

The bull was sound within 24 hours and the lameness did not recur. Haemorrhage is evident in the sole of this claw at the site of a sole ulcer and the farmer was advised regarding routine foot trimming in a tilting crush specifically designed for bulls.

CASE 1.12

1 What conditions would you consider (most likely first)? Include: vagus indigestion; localised peritonitis; LDA; traumatic reticulitis.

2 How would you confirm your diagnosis? A diagnosis of vagus indigestion is based on the clinical findings (rumen hypermotility and abdominal shape) and exclusion of other conditions. Localised peritonitis, often arising from traumatic reticulitis,

is considered to be the most common cause of vagus indigestion where the heart rate is normal. Ultrasonographic examination of the anterior abdomen using a 5 MHz sector scanner failed to detect any abnormality. Ultrasound-guided abdominocentesis yielded a small quantity of straw-coloured peritoneal fluid with a low protein concentration and low cell count comprised mainly of lymphocytes (normal values). 3 What actions/treatments would you recommend? The prognosis for this bull was considered to be very poor due to the chronicity and severity of the abdominal distension and he was sent for slaughter, therefore no necropsy findings were available. Postmortem examination often fails to reveal any significant gross lesion other than massive distension of the forestomachs (1.12b, gas has been released from the rumen).

CASE 1.13

1 What are the possible causes? Physical obstruction/choke; pressure on the oesophagus by enlarged mediastinal and bronchial lymph nodes related to previous bout of bronchopneumonia; thoracic mass (thymic lymphosarcoma); poor diet. It is often not possible to diagnose a specific cause.

2 What action would you take? Pass an orogastric tube to relieve accumulated gas. Insert a trochar/cannula (1.13b) or create a rumen fistula if the problem recurs more than once per day over the following 3-4 days. Check for presence of chronic pneumonia; may ultrasound scan chest and treat accordingly (e.g. prolonged penicillin therapy for chronic suppurative pneumonia). If a trochar is inserted in the summer months, check regularly for cutaneous myiasis of the wound edges. Review diet, especially protein content, if no cause of the bloat is found. However, a single case in a group of growing cattle suggests that diet would be an unlikely cause.

3 How can you tell when the problem has resolved? Plug the trochar after 2-3 weeks to check whether the bloat returns or if the primary problem has been successfully treated. If the bloat does not return after several days, remove the trochar and the flank wound will quickly seal the rumen, which is now firmly adherent to the abdominal wall. A rumen fistula will close by granulation tissue from the wound edges after approximately 2-3 months.

CASE 1.14

1 What conditions would you consider (most likely first)? Bovine neonatal pancytopenia (BNP); coagulopathy associated with septicaemia.

BNP is a recently emerged disease of calves that has been described across Europe since 2007. It presents as a bleeding disorder of calves less than

1 month old resulting in a high level of mortality due to bone marrow trilineage hypoplasia accompanied by depletion of peripheral thrombocytes and leucocytes. The disease is mediated by ingestion of alloantibodies in colostrum from particular cows and the subsequent binding of these alloantibodies to calf haematopoietic cells. BNP is strongly associated with the use of a particular BVDV vaccine (Pregsure® BVD; Pfizer Animal Health) in the dams of affected calves.

2 What treatments would you consider? There is no treatment and affected calves should be euthanased for welfare reasons. Where doubt exists over the

diagnosis, symptomatic treatment with antibiotics and NSAIDs could be considered.

3 How would you confirm your diagnosis? Haematology reveals a massive leucopenia and thrombocytopenia. The disease is characterised by a hypoplastic or aplastic bone marrow at necropsy with multifocal petechial, ecchymotic and suffusive haemorrhages (1.14b).

4 What preventive measures could be adopted? In this beef herd BNP cases stopped when colostrum ingestion was prevented by muzzling the calf for the first 36 hours of life, and feeding colostrum obtained from a dairy herd not vaccinated with Pregsure® BVD. The beef cows were milked for 36 hours after calving and the colostrum and milk discarded.

CASE 1.15

1 What conditions would you consider (most likely first)? Tumour arising from the periosteum; granulation tissue associated with penetrating foreign body; sequestrum.

Sequestrum formation in the mid- third metatarsal/metacarpal region is occasionally encountered in 1-2-year- old cattle, with bulls more commonly presented than heifers/steers.

2 What further examination could you undertake? Radiography reveals thickening of the cortex underlying the well-circumscribed soft mass and marked periosteal reaction (1.15b). There is mineralisation of the mass where it is adherent to the periosteum.

3 What action would you take? The cow

is not lame and removal of the mass would be neither simple nor inexpensive. Re­growth would be a possibility. Analgesia could be achieved under deep xylazine sedation and large volume (3 mg/kg lidocaine) low extradural block. IVRA would be difficult to achieve with the lesion so high up the third metatarsal bone. Perhaps the pragmatic approach to cull the cow and use the sale value to part finance the purchase of a replacement heifer would be the best option. A biopsy might give a more informed prognosis but the farmer decided to cull the cow without incurring further expense.

CASE 1.16

1 Describe the important sonographic findings and your interpretation. The bright linear echo formed by normal visceral pleura is present in the dorsal lung field but is replaced ventrally by hypoechoic areas extending up to 4-8 cm into the lung parenchyma, consistent with extensive lung consolidation.

2 What pathology does the sonogram represent? There is extensive lung consolidation consistent with chronic bronchopneumonia and subsequent bronchiectasis. Bronchiectasis has been defined as a dilation of a segment of a bronchus and is the result of a chronic bacterial or mycotic infection with destructive

inflammation of the wall of the bronchus in chronic, undrained, purulent bronchitis with or without bronchopneumonia. Grossly dilated bronchi are filled with a viscous, purulent, yellow-green exudate comprising of large collections of inflammatory cells with collapse of the surrounding parenchyma (1.16b). These permanently dilated small bronchi and bronchioles, located in ventral parts of the lungs, contain a range of microorganisms including Mannheimia hemolytica and Pasteurella multocida, but especially Trueperella pyogenes.

T. pyogenes is a gram-positive coccobacillus that becomes established only following compromise of the host's physical, cellular or secretory defence mechanisms, often after viral, mycoplasmal and bacterial infections. Infection with T. pyogenes is commonly associated with persistent BVDV infection in growing cattle. Concurrent infection with Fusobacterium and other anaerobic bacteria is not uncommon, causing halitosis.

3 What treatment would you give? The most effective (and inexpensive) treatment is 22,000 IU∕kg procaine penicillin administered IM daily for up to 6 weeks, with a good treatment response within 2-3 days. However, this heifer failed to respond to antibiotic therapy due to extensive lung pathology and was euthanased for welfare reasons; bronchiectasis was demonstrated at necropsy by squeezing the consolidated lung areas with pus expressed from the lower airways (1.16b).

CASE 1.17

1 What condition would you consider the most likely cause? Peracute bovine respiratory syncytial virus (BRSV) infection (with secondary bacterial infection).

2 What action should the farmer have taken? The first few clinical cases in a respiratory disease outbreak are typically the most severely affected, therefore veterinary attendance is essential at the start of any respiratory disease problem. Veterinary examination is essential to identify the likely cause, exclude other potential causes of this outbreak, such as IBR, collect appropriate samples and decide on the best antibiotic therapy.

In this calf that died, a single injection of a soluble corticosteroid, such as dexamethasone, was indicated to reduce the immune-mediated/allergic type reaction associated with inhalation of viral antigen into the caudodorsal lung that occurs in severe cases of BRSV-induced respiratory disease. Such treatment may have been life-saving. The benefits of NSAIDs such as ketoprofen and flunixin meglumine remain equivocal in such cases of severe respiratory disease caused by BRSV.

Few farmers request veterinary attendance at the beginning of a respiratory disease outbreak; instead they rely on whole group antibiotic injection without any monitoring, which is not only more costly but often results in chronic cases. From the farmer's perspective, whole group antibiotic injection requires much less labour/time. Whole group antibiotic therapy is contrary to the policy of veterinary organisations in many countries worldwide, including the British Veterinary Association, on antibiotic usage and the One Health concept on antibiotic resistance. There can be little justification for the use of fluoroquinolone antibiotics in bovine respiratory disease, especially when used in a metaphylaxis approach.

3 What control measures could be adopted for future years? Vaccination against BRSV, preferably by the intranasal route, should be completed at least 2 weeks prior to housing. The enterprise should be evaluated for risk factors such as high stocking density, high humidity and poor ventilation of farm buildings, mixed age housing and weaning/dietary stress factors after housing. Purchased cattle must not be mixed with homebred cattle.

CASE 1.18

1 What is this condition? Congenital joint laxity and dwarfism (CJLD). CJLD is a congenital (non­inherited) skeletal anomaly reported in beef herds worldwide, with clusters of calves born with severe shortening of long bones, tendon laxity and occasionally brachygnathia.

2 How can the problem be investigated? Calves are born with disproportionate dwarfism, shortening of the diaphyses, misshapen epiphyses and variable joint laxity (1.18b).

3 What control measures can be introduced? The aetiology is unknown, although some authors have suggested manganese deficiency as a possible cause. The problem is associated almost exclusively with spring calving beef herds where cows are fed a silage-based diet without straw or cereal supplementation during the winter months. Damage to the developing fetus probably occurs between 3 and 6 months of gestation. An unknown dietary teratogenic factor may be involved, but none has been identified.

There is no treatment and although joints stabilise and calves may walk normally, they remain chronically stunted and have no value for beef production. In herds where the disease has occurred, problems in subsequent years can normally be prevented by supplementing the silage-based diet during mid trimester with some hay/straw and cereals.

CASE 1.19

1 What conditions would you consider (most likely first)? Include: persistent infection with BVDV; chronic suppurative pneumonia or other septic focus; poor dam milk yield/mastitis; congenital abnormality.

2 What tests would you undertake? A blood sample result was BVDV antibody negative/antigen positive, (probably) indicating a persistently infected BVDV animal. While retesting would be necessary in 1 month's time to differentiate from a transiently viraemic animal, this would be unlikely when the calf shows typical clinical signs of persistent BVDV infection. The faecal worm egg count was low at 100 strongyle epg (probably Ostertagia spp.).

3 What other clinical problems could be expected? Potential problems include a poor pregnancy rate in the breeding cattle in the group due to embryonic/early fetal death if infected by BVDV. In-utero infection of the developing fetus in seronegative females between 45 and 135 days results in the birth of a persistently infected calf with cerebellar hypoplasia/hydranencephaly, a common manifestation of fetal infection later in this period. Transient infertility of the bull could result after virus infection if he was seronegative. Abortions can be expected at 4-7 months of gestation in susceptible animals.

4 How could this scenario have been prevented? National eradication programmes have proved very successful in several countries in the EU and are progressing well in other member states. In other countries, prevention of disease could involve establishment and maintenance of a BVDV-free herd by serological screening of all purchased cattle and strict biosecurity including double fencing of all perimeters. A concurrent vaccination programme of all breeding cattle would appear to be the safest option where doubts exist over herd biosecurity. However, a recent study revealed that 21% of farmers vaccinated cattle using the incorrect dose of vaccine or by the wrong route, and nearly 50% had the wrong interval between doses.

CASE 1.20

1 Where is the lesion? The lesion lies between in the spinal cord between C6 and T2.

2 What lesion would you suspect (most likely first)? The most likely lesion is vertebral empyema originating in one of the articular facets extending to involve the vertebral body and into the vertebral canal causing cord compression (1.20b). Despite the chronic nature of the empyema (several weeks to months), the calf may present with sudden onset of neurological signs. Certain Salmonella serotypes, especially S. dublin, can cause such bone infections.

Other lesions include: vertebral body fracture - sudden onset of neurological signs and pain associated with movement of the head (more commonly affects C4/C5); vitamin E/selenium deficiency - recumbency caused by white muscle disease presents as a bright, alert calf weak on all four legs.

3 What ancillary tests could you undertake? Further tests to identify a vertebral body lesion (bone lysis) are difficult even with excellent quality radiographs. Myelography can be performed but is expensive and not without risk. Lumbar CSF

analysis is a useful indicator of an inflammatory lesion causing spinal cord compression with an increase in protein from 0.3 g/l to >1.2 g/l (30 mg/dl to >120 mg/dl).

4 What is the prognosis? Compressive spinal cord lesions (see 1.20b), whether traumatic or inflammatory in origin, offer a grave prognosis and this calf was euthanased for welfare reasons.

CASE 1.21

1 What is the cause (most likely first)? Necrotic stomatitis (calf diphtheria); actinobacillosis.

Fusobacterium necrophorum causes a necrotic stomatitis typically seen in young dairy calves kept under unhygienic conditions with dirty feeding equipment. Lesions may also follow trauma to the buccal cavity caused by oesophageal feeders used to administer either colostrum or oral electrolyte solutions, and dosing gun injuries. Infection may extend to involve the larynx, causing anorexia, pyrexia, frequent harsh coughing, inspiratory stridor (roaring, honking) audible from a considerable distance and dyspnoea. The laryngeal region is swollen and palpation is resented. Death due to asphyxiation with necrotic debris occluding the lumen may occur if animals remain untreated for several days.

2 What treatment would you recommend? Calf diphtheria is treated with procaine penicillin (IM injection for 5-7 consecutive days). Parenteral potentiated sulphonamides and oxytetracycline are also effective.

3 Are there any control measures? The disease is prevented by high standards of hygiene when rearing dairy calves. In this situation the farmer was administering colostrum to calves slow to suck by an oesophageal feeder, which was never cleaned or disinfected.

CASE 1.22

1 What are your observations/comments? The calving ropes and calving aid are filthy, which could introduce infection into the posterior reproductive tract/uterus when placing them around the calf's legs and/or head. Any unnecessary manual interference at calving greatly increases the risk of puerperal metritis, although the farmer says that few cows are sick after calving. You recommend that you review the calving records to compare those cows that calve unaided with those requiring ‘assistance', but only the minimum data of the birth dates of the calves are recorded.

Puerperal metritis commonly affects cows after unhygienic manual interference to correct fetal malpresentation/malposture, after delivery of twins or a dead calf and following infectious causes of abortion. In most of these situations, there is retention of some, or all, of the fetal membranes. Cows suffering hypocalcaemia during second stage labour have an increased incidence of retained fetal membranes (RFM) and metritis. Bacterial entry and multiplication within the uterus produces toxins, which are absorbed across the damaged endometrium. Vaginal examination often stimulates discomfort and vigorous straining, and reveals copious amounts of red-brown foetid fluid.

RFM should only be removed if they come away with gentle traction, but this is rarely undertaken in beef cattle and the placenta(e) are passed after 5-7 days without apparent adverse effects (1.22b). This situation differs significantly from dairy cattle, where retained placentae often give rise to clinical illness. The future reproductive performance of beef cows in relation to calving ease is rarely investigated in beef herds apart from comments on caesarean operations if the cow fails to become pregnant. Surprisingly, cystitis progressing to pyelonephritis appears to be unrelated to dystocia.

Assisting more than 50% of the herd to calve is far too high a percentage; ideally this figure should be zero, but twins and those calves in posterior presentation often need assistance. Selecting a bull based on calving ease would be a significant step forward, not least for animal welfare reasons.

CASE 1.23

1 What are these lesions? Capped hocks, cellulitis and effusion of the hock joint. Capped hocks are common in dairy cows caused by repeated trauma from unyielding (concrete) lying surfaces.

2 What is the likely cause? Poor cubicle design coupled with insufficient or inappropriate bedding material leads to repeated trauma and skin damage; skin penetration and development of cellulitis may result.

3 What action should be taken? Hock swellings are an indication of poor housing and can be readily prevented by good cubicle design, maintenance and amount and type of bedding material. The prevalence of hock swellings in dairy cattle has been used as an outcome measure of cow welfare. An example of very poor maintenance of sand bedded cubicles is shown (1.23b). Prevalence of hock and carpal lesions should be interpreted alongside whole herd lameness scoring. No treatment is necessary; prevention is important.

Infected (cellulitis) lesions are best treated with procaine penicillin or cephalosporin, the latter having no milk- withhold restriction in many countries. Lancing any large lesion should be carefully considered because this often results in considerable haemorrhage from blood vessels in the thick fibrous capsular wall. Furthermore, the incision site quickly seals over. Prior ultrasound scanning of the lesion would identify the nature of the swelling and the extent of any subcutaneous abscess.

CASE 1.24

1 What is the cause of this problem (most likely first)? Fracture of sacral vertebra(e) (crushed tail head syndrome, a vague term that refers to an injury to the sacral or coccygeal vertebrae of dairy cows following mounting activity, causing variable spinal nerve injury leading to tail paresis/paralysis and, in some cases, bladder dysfunction and sciatic nerve deficits). A lesion at S2-S4 would explain the clinical signs shown by this cow.

2 What treatment would you administer? In acute cases, treatment with NSAIDs or corticosteroids may reduce the local inflammation and improve neurological function temporarily, but the prognosis for full recovery is guarded. Careful palpation of the ventral surface of vertebral column per rectum may reveal the sacral fracture (1.24b).

3 What action would you take? This cow was euthanased and the sacral fracture confirmed at necropsy. Emergency on-farm slaughter could be considered but the carcass value of a dairy cow is often too low to be financially viable; transport to a slaughter plant cannot be justified for welfare reasons.

CASE 1.25

1 What area of the brain could be involved? The clinical signs are suggestive of a cerebellar lesion. The calf has shown clinical signs for the past month only, therefore a developmental lesion rather than a congenital lesion would be suspected.

2 What conditions would you consider? Cerebellar abscess; cerebellar abiotrophy.

3 What tests could be undertaken? A cerebellar abscess was considered to be the more likely diagnosis. A lumbar CSF sample collected under local anaesthesia revealed a clear and colourless sample, but laboratory examination showed increased protein and white cell concentration comprised almost exclusively of

neutrophils. There was no history of BVDV infection on this closed unit.

4 What action would you take? Antibiotic therapy is ineffective in treating large abscess(es) in the brain regardless of location and the calf was euthanased because of the hopeless prognosis. An abscess in the cerebellum was identified at necropsy (1.25b).

CASE 1.26

1 What conditions would you consider (most likely first)? Coccidiosis; poor nutrition; salmonellosis. Coccidiosis is caused by infection by the protozoan Eimeria spp., which parasitize the epithelium lining of the alimentary tract. E. zuernii, E. bovis and E. alabamensis are the most common and pathogenic. Infection causes loss of epithelial cells and villous atrophy, with consequent diarrhoea and possibly dysentery. Outbreaks of disease are commonly seen 3-4 weeks after mixing groups of dairy calves.

2 How would you confirm the diagnosis? Diagnosis is based on epidemiological and clinical findings affecting most calves in a group. Demonstration of large numbers of oocysts in faecal samples is helpful, but speciation is rarely undertaken in field outbreaks because of laboratory costs. Remember that small numbers of oocysts are

present in the faeces of many normal calves and the stage of infestation greatly influences the number of oocysts present in faeces. There is a good response to specific anticoccidial therapy. Histopathology findings in a dead calf confirm the clinical diagnosis.

3 What treatment would you recommend? Move calves from the infected building immediately. A sulpha drug given orally for 3-5 days is a common treatment. Toltrazuril and diclazuril can be used for both treatment and prophylaxis. Oral fluid therapy may be indicated in certain cases. Decoquinate can be used in-feed for prevention of coccidiosis in diary calves. Monensin sodium is used as a coccidiostat in many countries, but is not licensed within the EU.

Strict attention to disinfection of buildings between batches of calves and clean feeding areas mean that coccidiosis is uncommon in modern dairy units. Disease caused by E. alabamensis may result from contaminated water courses in pastured calves during summer months (1.26b). As survival of oocysts is possible from one year to another, calving on the same pasture each year may increase the disease risk.

CASE 1.27

1 What diseases would you consider (most likely first)? Include: environmental (coliform) mastitis; hypocalcaemia; acute septic metritis; other infectious conditions causing toxaemia/endotoxaemia; trauma at parturition resulting in a ruptured uterus; salmonellosis; botulism.

2 Which disease(s) is most likely? Coliform mastitis causing endotoxic shock is the probable cause of this clinical appearance. It may prove difficult to rule out the possible contribution of hypocalcaemia and many clinicians may elect to administer 400 ml of 40% calcium borogluconate slowly by the IV route while monitoring the cow’s heart rate. Constipation is more likely in hypocalcaemia than diarrhoea.

3 What treatments would you administer? Treatment of endotoxic shock (coliform mastitis) includes IV injection of a NSAID, repeated 12 hours later. Hypertonic saline (7.2%) infusion (5 ml/kg; 3 litres for a 600 kg [1,320 lb] cow) within 5-7 minutes is achieved through a 13 gauge/4 inch jugular catheter. Access to 30-60 litres of warm water, which may contain electrolytes, must be provided, although not all cows drink. Some clinicians recommend stomach-tubing volumes up to 30-40 litres if the cow does not drink immediately. This cow made a full recovery. Mastitis caused by Streptococcus uberis can present with many of the clinical features of coliform mastitis and it may prove prudent to administer a broad-spectrum antibiotic both parenterally and by intramammary infusion.

4 What control measures could be adopted? Control measures include proper hygiene in the calving accommodation (1.27b). Use teat sealants at drying-off. Consider use of J5 E. coli core antigen vaccine. Include pre­milking teat dipping in the parlour routine. Keep cows standing for 30 minutes after milking by offering fresh feed to enable complete teat sphincter contraction before lying down. Sand-bedded cubicles perform better than those bedded with sawdust. Ensure ventilation in the cubicle shed and a maximum occupancy of 90%.

CASE 1.28

1 What area of the brain could be involved? The clinical signs are suggestive of a cerebellar lesion. The calf has shown clinical signs since birth, therefore a congenital rather than a developmental lesion would be suspected.

2 What conditions would you consider? Cerebellar aplasia/hypoplasia; cerebellar abscess/focal meningitis; cerebellar abiotrophy; hydranencephaly. Cerebellar hypoplasia was considered to be the most likely diagnosis. The possible involvement of BVDV during fetal development could not be further examined because of the presence of maternally-derived antibody in the calf (unless the dam was a persistently infected BVD animal herself and therefore seronegative). Congenital BVDV infection is a common cause of cerebellar hypoplasia in calves with clinical

signs apparent from birth. Doming of the head caused by hypertensive hydrocephalus is an uncommon finding associated with congenital BVDV infection.

A lumbar CSF sample was collected under local anaesthesia. The sample was clear and colourless and laboratory examination revealed a normal protein concentration and white cell concentration. There was no evidence of infection of the central nervous system, therefore antibiotics were not indicated.

3 What action would you take? BVDV was subsequently isolated from a peripheral blood sample from this calf. Necropsy revealed gross evidence of cerebellar hypoplasia (1.28b).

CASE 1.29

1 What conditions would you consider? Congenital pseudomyotonia; cerebellar abiotrophy/abscess; otitis media; muscular dystrophy (white muscle disease); tetanus; Schmallenburg virus infection.

2 What tests could be undertaken? Brody’s disease is a rare human congenital disorder associated with exercise-induced impairment of muscle relaxation. The underlying cause for this condition has been determined to be a mutation of the ATP2A1 gene resulting in disturbed calcium reuptake into the sarcoplasmic reticulum at the end of the contractile phase. Recently, diseases associated with different /ATP2A1/ gene mutations have been described in the Chianina and Belgian Blue breeds and termed pseudomyotonia and congenital muscular dystonia 1, respectively. Analysis of the collected Chianina pedigree data suggested that congenital pseudomyotonia has monogenic autosomal recessive inheritance.

3 What action would you take? A further two calves were affected out of 40 calves born alive. All three affected calves were the progeny of a recently purchased Charolais bull. This bull was culled because of the hereditary component of this disease; no affected calves were born in the following four breeding seasons.

CASE 1.30

1 What conditions would you consider (most likely first)? Malnutrition/poor dam milk yield; parasitic gastroenteritis; coccidiosis; copper deficiency. A trace element deficiency problem would be expected to affect the majority/all of the growing animals in the group and in this herd only several of 30 calves are affected, suggesting that poor dam milk yield/nutrition could be a contributing factor. A thin, dry, sparse hair coat should not be confused with delayed shedding of winter coat (see 1.30). Faecal worm eggs were negative; ostertagiosis is not usually a problem until much later in the grazing season.

2 What samples could you collect? Plasma or serum copper levels are suitable for the diagnosis of clinical disease, but not for the estimation of body copper reserves. A group of seven to 10 cattle should be sampled to establish a diagnosis. Liver biopsy samples from three to four animals give an indication of body copper reserves, and can be used to monitor copper supplementation. Response to treatment is perhaps the most important indicator of copper deficiency; randomly treat 15 calves in this group and leave 15 calves unsupplemented. Injectable copper compounds vary in respect to their speed of absorption from the injection site and duration of activity, but a growth response, if present, would be detected within 6-8 weeks.

3 What advice would you offer? Where the cause of poor growth is caused by poor dam milk supply, provision of creep feed should improve calf growth rates. As the protein content of spring grass is likely to be adequate, barley or another cereal would suffice.

CASE 1.31

1 How would you collect a lumbar CSF sample? It is necessary to puncture the subarachnoid space at the lumbosacral site. Collection of lumbar CSF is facilitated if the animal can be positioned in sternal recumbency with the hips flexed and the hind legs extended alongside the abdomen (this case); samples can also be collected when the animal is standing restrained in cattle stocks. The site for lumbar CSF collection is the midpoint of the lumbosacral space identified as the midline depression between the last palpable dorsal lumbar spine (L6) and the first palpable sacral dorsal spine (S2). The site must be clipped, surgically prepared and between 1 and 2 ml of local anaesthetic injected SC. The needle (see below for a guide to needle length and gauge) is slowly advanced (over 10 seconds) at a right angle to the plane of the vertebral column or with the hub directed 5-10° caudally. It is essential to appreciate the changes in tissue resistance as the needle point passes sequentially through the subcutaneous tissue and interarcuate ligament, then the sudden ‘pop’ due to the loss of resistance as the needle point exits the ligamentum flavum into the extradural space. Once the needle point has penetrated the dorsal subarachnoid space, CSF will well up into the needle hub within 2-3 seconds. Between 1 and 2 ml of CSF is sufficient for laboratory analysis and while the sample can be collected by free flow over 1-2 minutes, it is more convenient to employ very gentle syringe aspiration over 10-20 seconds (1.31b).

• Calves 250 kg 4 inch, 18 gauge + internal stylet

The normal range of CSF protein concentration quoted for cattle is extensive erosion of articular cartilage. There is marked osteophytosis of the second phalanx.

2 What is the likely cause(s) of this condition? Puncture wound of the distal interphalangeal joint, although none is visible. Ascending infection from a sole ulcer is the more common aetiology in dairy cattle.

3 What is the likely duration of this condition? The development of these bony lesions would likely have taken a minimum of 3-4 months, during which time the cow would have been severely lame. It is likely that the history of 4 weeks' lameness is a gross underestimate of this cow's suffering. The chronicity of such lesions is clearly demonstrated by radiographic changes (1.35b).

4 Has this cow received appropriate treatment and care? Interdigital necrobacillosis (foul of the foot) is a common cause of severe lameness in cattle at pasture and responds rapidly to antibiotic therapy provided there is no penetrating foreign body in the interdigital space. It is unreasonable to wait (at least) 3 weeks without improvement before requesting veterinary assistance.

5 How can this problem be resolved? Digit amputation under IVRA. Flunixin meglumine (or other NSAID) is injected IV before surgery. A robust tourniquet is placed below the hock. Thirty ml of 2% lidocaine solution is injected into the superficial vein running on the craniolateral aspect of

the third metatarsal bone; analgesia is effective within 2 minutes. The affected digit is removed using embryotomy (Gigli) wire through distal P1. A pressure bandage is applied to limit haemorrhage, removed after 3-4 days and a light dressing applied for a further 3-4 days.

CASE 1.36

1 Describe the important features shown. There is marked soft tissue swelling and considerable lysis around the root of the third permanent molar tooth of the left mandible, with localised bone remodelling.

2 What conditions would you consider (most likely first)? Tooth root abscess; actinomycosis; bone neoplasia. The bone lesion appears to be too focal for Actinomyces bovis infection, which typically causes a more extensive pyogranulomatous osteitis/ osteomyelitis in the maxilla and mandible of adult cattle.

3 What treatment would you recommend? The response is likely to be poor even with prolonged antibiotic therapy. Extraction of the tooth was attempted per os but it could not be removed; more excessive force could have caused mandibular fracture. Discussions with the insurers resulted in an agreed plan to treat the bull for 2 weeks with a penicillin and streptomycin combination and re-evaluate after that treatment period. Initially, there was improvement with an increase in the bull's appetite, but this situation lasted only a few days. The bull started quidding again and the decision was taken to euthanase the bull for welfare reasons; the meat withdrawal period dictated by the antibiotic treatment was considered too long for the bull's welfare so there was no carcass value. Radiographs in this case provided an accurate assessment of the lesion, which aided discussions with the insurance company's expert assessors.

CASE 1.37

1 Describe the sonogram. There is loss of the bright linear echo formed by normal visceral pleura, replaced by a hypoechoic area containing numerous 1.5-2.0 cm well-encapsulated circular anechoic areas containing multiple hyperechoic dots typical of abscesses. This sonogram is typical of chronic suppurative pneumonia; the demonstration of bronchiectasis requires postmortem examination, but such pathology is typical in such cases.

2 What conditions would you consider? Chronic suppurative pulmonary disease (CSPD) and bronchiectasis.

3 What treatment would you recommend? Trueperella pyogenes is most commonly isolated from such cases with lung abscessation and bronchiectasis and typically follows incomplete/inappropriate antibiotic treatment for acute respiratory disease, often caused by Mannheimia haemolytica. The most effective treatment is 22,000 IU∕kg procaine penicillin (IM daily for up to 6 weeks), with a good treatment response within 2-3 days. This heifer responded well to treatment, but a rescan of her lungs showed little change after 6 weeks treatment (1.37b). The animal improved because infection was cleared from the airways (bronchiectasis); lung abscesses remain unaffected.

4 What is the prognosis for this heifer? The response rate for CSPD largely depends on the extent of pathology, which can be determined ultrasonographically. As a guide, the prognosis is reasonable if the extent of the lung pathology, measured in a vertical plane from the point of the elbow on both sides of the chest, totals less than 40 cm in a mature cow; scale down to ca. 25 cm in a bulling heifer (guideline only). The extent and chronicity of these lung lesions were severe and the farmer was advised not to breed this heifer and cull her for beef when she reached a marketable weight.

CASE 1.38

1 What is the definition of a downer cow? A cow that has been sternally recumbent for more than 24 hours, is not suffering from hypocalcaemia and has no obvious condition (e.g. mastitis, toxaemia or injury).

2 What is the likely cause? Downer cow syndrome has a multifactorial primary aetiology mostly related to dystocia and milk fever. Unless the initial cause of recumbency is promptly treated, lying in one position for more than 6 hours results in muscle damage and ischaemic necrosis, which may become irreversible after 12 hours' recumbency in the same position.

3 What treatment would you administer? Move to a dry, clean comfortable lying area, either a deep-bedded straw pen or outside into a sheltered grass paddock. The cow must be turned every 3 hours to prevent pressure damage to muscles and nerves. Ensure provision of ad-libitum good quality food and fresh water. A NSAID or corticosteroid injection reduces pain and tissue damage, as well as improving demeanour and appetite. Assist the cow in attempting to stand using cow nets, supportive harness, inflatable bags and water flotation tanks. Hip clamps (Bagshaw hoist) may be used once to assist diagnosis; however, repeated application may cause severe muscle damage.

4 What is the prognosis for this cow? Cows that cannot maintain sternal recumbency and fall into lateral recumbency, and are depressed or hyperaesthetic, have a poor prognosis. Cows that make repeated attempts to rise and can move themselves about are often called ‘creepers' or ‘crawlers'. Such cows are usually bright and alert, and have a good prognosis.

CASE 1.39

1 What conditions would you consider (most likely first)? Include: bacterial endocarditis; chronic suppurative pulmonary disease; pleural effusion/abscess; traumatic reticuloperitonitis; septic pericarditis; myocarditis.

Surprisingly, despite the sometimes large vegetative lesions present on heart valves, heart murmurs are inaudible in most cases of endocarditis. Transthoracic ultrasonographic examination of heart valves requires a sector scanner. Transthoracic

l.39b

ultrasonography revealed no evidence of lung pathology on either side of the chest. There was no peritoneal effusion ruling out traumatic reticuloperitonitis.

2 What treatment would you recommend? The organisms most commonly isolated from endocarditis lesions, including streptococci, are sensitive to penicillin. Treatment with 22,000 IU/kg procaine penicillin administered daily was commenced and a single injection of dexamethasone given IM (cow not pregnant).

3 What is the prognosis? The prognosis for endocarditis cases is hopeless but it is difficult to establish a definitive diagnosis; therefore, antibiotic therapy is often administered in case another treatable condition has been overlooked (unlikely in this cow as all other possibilities had been excluded from the differential diagnosis list). This cow failed to respond to treatment and was euthanased. At necropsy a large vegetative lesion was present on the tricuspid valve (1.39b). The liver was enlarged as a consequence of chronic venous congestion and the cut surface had the typical ‘nutmeg appearance'. There were numerous infarcts in the kidney. No primary septic focus was found but this is not unusual.

CASE 1.40

1 What conditions would you consider (most likely first)? Pharyngeal abscesses/ enlarged retropharyngeal lymph nodes; oral and laryngeal lesions caused by Fusobacterium necrophorum; actinobacillosis of retropharyngeal lymph nodes.

Pharyngeal abscesses/enlarged retropharyngeal lymph nodes in cattle result from penetration wounds, most commonly caused by incorrect drenching/ bolus administration. It is not always possible to distinguish the deep-seated retropharyngeal lymph nodes even when they are grossly enlarged.

2 How would you confirm you diagnosis? Diagnosis is not simple, especially when the infection has tracked along fascial planes and may erupt distant to the entry site in the pharynx. History of recent drenching/bolusing provides strong circumstantial evidence of pharyngeal trauma. Poor appetite resulting from enlarged

retropharyngeal lymph nodes (1.40b) or an abscess can prove difficult to diagnose. Radiography to illustrate soft tissue swellings, and possibly a fluid line should a large abscess be present, can prove very helpful but such facilities are not readily used in practice. Endoscopy and ultrasound- guided needle aspiration are also possible diagnostic techniques.

3 What treatment(s) would you administer? Response to broad­

spectrum systemic antibiotic treatment for 10-14 days (e.g. clavulanate potentiated amoxycillin or penicillin/streptomycin) will be variable depending on the extent of pharyngeal trauma/abscessation. Surgical drainage of retropharyngeal abscesses is possible via the oral cavity or using a lateral approach, but is not without risk.

CASE 1.41

1 What conditions would you consider (most likely first)? Epididymitis; orchitis; photosensitisation; inguinal hernia.

2 What further investigations would you undertake? Ultrasonography (1.41b) reveals marked swelling of the tail of the epididymis (5 MHz linear scanner,

ventral pole of testicle to the left side with the tail of the epididymis to the right, there is marked thickening [oedema] of the scrotal skin). These findings are consistent with a diagnosis of epididymitis. Rectal examination reveals enlarged seminal vesicles. There is no evidence of orchitis. This bull is intended for fattening; semen collection would be indicated after a further 3 months to assess semen quality in potential breeding bulls but is not indicated in this case. Repeat ultrasonography would be helpful to monitor treatment.

3 What is the likely cause? Numerous bacteria including Trueperella pyogenes,

E. coli, Histophilus somni and Staphylococcus spp. have been isolated from cases of orchitis and epididymitis.

4 What treatment would you administer? The bull was treated with florfenicol and was much improved the following day. The florfenicol treatment was repeated on day 3. The bull was normal by day 4 and was slaughtered 3 months later; no repeat ultrasound examination was considered necessary.

CASE 1.42

1 What conditions would you consider (most likely first)? Nervous acetonaemia/ ketosis and LDA. Excessive loss of body condition may have led to development of a severely fatty liver and other parenchymatous organs.

2 How could you confirm your diagnosis? Diagnosis of ketosis is based on clinical examination and confirmed by a positive cow-side Rothera's reagent test or laboratory demonstration of a 3-OH butyrate concentration in excess of 4.0 mmol/l. Various liver enzymes can be assayed to determine liver dysfunction caused by fat infiltration of the liver, but they tend to underestimate the severity of the problem. The LDA can be confirmed at corrective surgery (right omentopexy).

3 What treatment would you administer? Treatment included dexamethasone and 400 ml 50% dextrose IV. Propylene glycol was given orally along with 40-60 litres of warm water. Surgery to correct the LDA was postponed until the following day. The cow deteriorated overnight and was recumbent and unable to stand. The prognosis was hopeless and the cow was euthanased for welfare reasons. The highly friable and very fatty liver was evident at necropsy (1.42a, b). It can prove difficult to predict the extent of fatty infiltration of the liver even with an array of liver enzyme test results; liver biopsy is rarely undertaken in general practice. It is highly likely that this cow had been ill for much longer than the stated 24 hours.

4 How could this condition be prevented? A review of the far-off and close-up dry cow rations is necessary. Increased plasma NEFA concentrations are a good indicator of excessive fat mobilisation in the close-up dry period. Cows should enter the dry period in BCS 3/5 and maintain this value until calving. Excessive conditioning (BCS >4) is often the result of extended dry periods due to poor fertility.

CASE 1.43

1 What conditions would you consider? Femoral fracture; femoral nerve paralysis; sciatic nerve damage.

2 How could you confirm your diagnosis? Fracture through the distal femoral growth plate is demonstrated by radiography (1.43a, b).

3 What is the prognosis? Repair of the fracture was not possible and the calf was euthanased for welfare reasons.

4 How could this situation have been prevented? Excessive force using a calving jack to deliver oversized beef calves is not uncommon. Wherever possible, the cow should be haltered and released from the cattle stocks and allowed to assume lateral recumbency before pulling the calf. A caesarean operation was clearly indicated in this case.

CASE 1.44

1 Age at first calving. According to the English Beef and Lamb Executive (EBLEX), the age at calving in beef heifers is approximately 34 months. The target of calving beef heifers is 2 years old. While management and nutrition will be important factors, the extent to which disease contributes to poor liveweight gain and delayed breeding is not known.

2 Calving period. In England surveys show calving periods in the range of 20-22 weeks for 2010/11. Calving periods for beef suckler herds in Scotland were 14-16 weeks for 2010. The average calving intervals for suckler cows calving in England and Wales in 2010 were broadly similar, ranging from 440 to 446 days. Producers should be aiming for a compact calving period of 9 weeks. This suggests that 21% more calves are possible from the same number of cows by improving herd fertility and reducing the calving interval to an average of 365 days for all cows in the herd.

3 Barren rate. Data from enterprise costing surveys show barren cow rates in the range of 6.3 to 8.1 barren cows per 100 cows exposed to the bull in 2010. The industry benchmark for barren rate is less than 5% of females exposed to the bull.

4 Bull infertility. Up to 40% of bulls are subfertile. Bull fertility assessments are more often undertaken after detection of a high barren rate during a pregnancy diagnosis test or following an extended calving period. These fertility parameters are invaluable to those veterinary practitioners with a proactive approach to convincing their farming clients of the financial value of bull breeding soundness assessments ahead of the service period rather than after a problem has arisen. Whether semen collection using electroejaculation and microscopic analysis is a better assessment than palpation and ultrasound examination of scrotal content is another matter. The former assessment has proven popular with veterinary practitioners but there are few convincing published data to support this practice in UK beef herds.

CASE 1.45

1 What conditions would you consider (most likely first)? Liver fluke. Inadequate nutrition also presents as a whole group/herd problem of poor production and weight loss, but diarrhoea would be an uncommon finding.

2 How would you confirm your diagnosis? Undosed beef cattle grazing potentially infected pastures should either be treated or checked for the presence of fluke eggs in faeces (1.45b). Metacercariae ingested from pasture will be mature patent flukes by late winter (3-month pre-patent period). Liver enzymes, particularly GLDH and GGT, reflect liver and bile duct damage, respectively, but are not specific for liver fluke infection. Serology indicates past liver fluke infection but this may not be current. The coproantigen ELISA test detects digestive enzymes that are released into the bile by migrating (late immature) and adult flukes and

detected in faeces. Active fluke infection can be detected 3-4 weeks after infection but more reliably after 6-9 weeks, approximately 3-6 weeks before eggs can be detected in faeces.

3 What treatment would you administer? Triclabendazole is effective against developing flukes from several days old but is not necessary and should not be used for mature flukes. Closantel and nitroxynil are very effective against immature flukes from around 7 weeks post infection and can be used for the treatment of chronic fasciolosis. Albendazole and oxyclosanide are effective from 10-14 weeks post infection and such treatment is recommended to remove adult flukes in late spring.

4 What advice would you give to the farmer? Slaughterhouse data reveal that more than 25% of bovine livers are condemned because of liver fluke damage. The farmer should discuss such positive liver fluke results with their veterinary surgeon and develop an appropriate control programme.

CASE 1.46

1 What conditions would you consider (most likely first)? Femoral paralysis (the predominantly unilateral paralysis allows differentiation from a spinal lesion caudal to T2); congenital sarcocystosis; unilateral femoral nerve paralysis (should be differentiated from femoral fracture(s) [particularly through the proximal epiphysis], dislocated hip, pelvic fracture and infection of hip/stifle joints). Fractures of long bones following dystocia are rare and would be detected on careful clinical examination with radiography where appropriate.

2 What treatment would you administer? A single injection of dexamethasone may be useful (unproven) to reduce perineural swelling if the injury has just occurred (e.g. during calving [not this case]). NSAIDs could be administered but, as with the use of dexamethasone, there is no published evidence for their use in this situation. Calves with bilateral femoral nerve paralysis have a grave prognosis; unilateral injuries may take 6 months to fully recover. Careful examination of the calf is necessary to check for evidence of septicaemia and focal infections such as meningitis, polyarthritis, hypopyon, and omphlophlebitis, as these are more likely to result if there has been a delay/failure of passive antibody transfer due to the calf's recumbency and inability to find the cow's udder unaided.

3 How could this problem have been prevented? When a calf presents in anterior longitudinal presentation, two people pulling should be able to extend both fore leg fetlock joints one hand's breadth beyond the cow's vulva (indicates extension of the elbows into the pelvis) within 10 minutes. Any greater traction to achieve such progress forewarns of potential hip-lock and its consequences. This simple guideline is frequently ignored by farmers, when too much traction can also cause obturator and sciatic nerve damage to the cow; uterine prolapse is also not uncommon after prolonged dystocia and excessive traction.

CASE 1.47

1 What is the likely cause? Granulosa cell tumour; mastitis.

2 How would confirm your diagnosis? Transrectal ultrasonography (1.47b) reveals a multi-loculated mass, approximately 6 cm deep and 12 cm long, just beyond the pubis, consistent with a granulosa cell tumour.

3 What action could be taken? The tumour could be removed via a high right flank laparotomy under paravertebral anaesthesia, although there may be problems with exteriorisation of the tumour and effective ligation of its blood supply in the broad ligament. Access via a ventral midline approach under general anaesthesia may give better surgical access but is not without risk. The future breeding of the heifer is very difficult to predict because few such surgeries have been undertaken. Unless the genetic merit of the heifer is unique (which is seldom the case) the best financial option may be to cull the heifer for beef.

CASE 1.48

1 Describe the abnormal radiographic findings. There is marked soft tissue swelling and widening of the distal tibial growth plate. There is no evidence of significant bone lysis suggestive of infection.

2 What is the likely cause? Fracture involving the distal tibial growth plate.

3 What action should have been taken at the first veterinary examination? The animal was euthanased for welfare reasons after examination of the radiographs and the diagnosis confirmed at necropsy (1.48c). This type of fracture will not heal with casting the leg. The animal could not be slaughtered on-farm for human consumption because of prior antibiotic therapy.

Care must be taken when reaching a provisional diagnosis in cattle with sudden­onset severe lameness. If there is no evidence of infection, do not administer antibiotics. Sudden-onset severe lameness is most commonly caused by fracture of a long bone or joint trauma leading to marked effusion. Lameness caused by foot lesions and growth plate infections is more gradual in onset. NSAID injection is not an aid to diagnosis and is no excuse for an incomplete clinical examination - where doubt exists ask a colleague for a second opinion immediately.

CASE 1.49

1 What is this lesion? An extensive organised haematoma extending >30 cm from the probe head.

2 What is the likely cause? Trauma; a bulling injury would be possible in this age group. A coagulopathy may have been present at that time but was not investigated because only one animal was affected and there was no history of a similar problem on the farm.

3 What action should be taken? The mass has not reduced in size over 2 months

and the animal has difficulty rising, therefore the heifer should be euthanased for welfare reasons. Necropsy (1.49b) reveals that resorption of this haematoma has not occurred over 2 months and may not occur at all. The size and organised nature of the haematoma, which is firmly adherent to adjacent tissues, mean that attempted drainage would not have been possible and would simply have allowed infection to enter, with the development of a massive subcutaneous abscess.

CASE 1.50

1 Describe the important features of the sonogram obtained using a 5 MHz sector scanner in the sixth intercostal space approximately half way up the chest wall (1.50a). Ultrasound examination shows the absence of the hyperechoic line representing the visceral pleural (lung surface). There is approximately 5-6 cm of fluid (anechoic area) separating the chest wall and the pericardial sac, which of multiple hyperechoic dots), therefore it is not consistent with septic pericarditis. This case clearly demonstrates the clinical application of ultrasonography because the most likely cause on clinical examination would be septic pericarditis. At necropsy there was a large amount of blood within the pericardial sac from the tumour.

itself is distended to 5-8 cm. There is a large 5-10 cm hyperechoic mass firmly attached to the epicardium.

2 What conditions would you consider (most likely first)? These findings are consistent with a heart base tumour (1.50b). It is unusual to find significant pleural transudate in cattle with septic pericarditis. Furthermore, the fluid within the pericardial sac is uniformly anechoic and not purulent (absence

3 What treatment would you administer? There is no effective treatment and the cow should be euthanased immediately for welfare reasons. Indeed, this cow should have been euthanased several weeks ago and not allowed to deteriorate to this state.

CASE 1.51

1 What conditions would you consider (most likely first)? Hepatocaval thrombosis;

chronic suppurative pulmonary disease.

2 What tests could be undertaken to confirm your provisional diagnosis? A diagnosis of hepatocaval thrombosis is very difficult to confirm on clinical examination and is based on exclusion, where possible, of more common/ likely conditions. Epistaxis is the cardinal clinical sign of advanced hepatocaval thrombosis and indicates a hopeless prognosis such that affected cattle should be culled for welfare reasons. Often there is a minor bleed followed several days later by a fatal episode. Ultrasonographic examination of the chest would rule out chronic suppurative pulmonary disease; haematogenous spread from the thrombus gives a more caudodorsal distribution deeper within the lung parencyma. Ultrasonographic demonstration of the thrombus present in the caudal vena cava can be achieved in some cases, but such examination requires a sector scanner and is not commonly undertaken in general practice. Hepatomegaly, with rounded liver margins, would also be present, although not easily identified. A lesion involving a nasal passage would be unilateral.

3 What treatment would you administer? Effective treatment is limited by the difficulties inherent in early diagnosis of this problem. Theoretically, result in carcass condemnation. There is no effective treatment in cattle with significant pulmonary haemorrhage and these animals should be euthanased for welfare reasons.

procaine penicillin injected daily for at least 6 weeks may overcome the bacteraemia but will not remove the massive thrombus, with the result that further bacterial shedding is likely. This cow could be sent for slaughter. Chronic venous congestion leads to hepatomegaly and a ‘nutmeg appearance’ (1.51b). Evidence of significant bacteraemia with liver, kidney and lung involvement may

4 What control measures would you recommend? The role of subacute ruminal acidosis is proposed in the aetiology of this condition, therefore reducing risk factors for this condition may help, although there are no specific control measures.

CASE 1.52

1 What is the prognosis for this calf? The prognosis is guarded because there is already considerable damage to the gut and omentum in the 30 minutes it takes for you to attend. It is also impossible to render the omentum and serosal surface of the intestines sterile before returning them to the abdomen.

2 What action would you take, including details of your anaesthetic approach? Inject flunixin (or other NSAID) IV. Inject antibiotics IM - there are no specific recommendations, but amoxicillin/clavulaninic acid combination is often used. Protect the prolapsed intestines in a sterile plastic drape until replacement (see 1.52). There are a number of anaesthetic options but xylazine sedation followed by ketamine is the most commonly used. Xylazine is given IM (0.05-0.07 mg/kg) and the animal left for approximately 10 minutes. Induction of anaesthesia is then achieved by administering ketamine (3-5 mg/kg IV), which produces 10-20 minutes of surgical anaesthesia. Anaesthesia can be extended with incremental doses of ketamine (2-3 mg/kg IV), which give a further 10 minutes of surgical anaesthesia. Alphaxane (4.4 mg/kg IV) is very safe in young calves and gives 10 minutes of surgical anaesthesia. Propofol (4-6.5 mg/kg IV) can also be used.

Once surgical anaesthesia has been achieved, place the calf in dorsal recumbency and extend the hernial ring cranially with scissors taking great care not to damage the intestines present within the ring. Remove gross contamination and replace the prolapsed intestines while flushing all surfaces with sterile saline. Suture the incision and the hernial ring. The benefits of intra­abdominal antibiotics are debatable. Stomach tube with 3 litres of colostrum. Monitor carefully and continue antibiotics and NSAIDs for the next 2 days. The major risk is peritonitis, which will be manifest as reluctance to suck but with a distended abdomen due to static fluid-filled intestines and possible accumulation of exudate, dullness and colic.

3 How can this problem be prevented? This problem occurs sporadically, often caused by an overzealous dam with vigourous licking of the calf and the umbilical remnant. Some farmers maintain that application of iodine to the umbilicus aggravates this behaviour.

CASE 1.53

1 Describe the radiographic findings. A grid would have improved the quality of the ventrodorsal radiograph shown because of the large amount of muscle in this area. However, there is evidence of a shallow acetabulum and flattening of the femoral head affecting both hip joints.

2 What conditions would you consider? Include: hip dysplasia; osteochondrosis dissecans; rickets (would be unusual in this natural rearing system).

3 What action would you take? There is no treatment and the calf should be euthanased for welfare reasons. The severity of the hip lesion is evident at necropsy (1.53b). Portable x-ray facilities are available in most large animal practices but are rarely used in cattle, mainly because of cost. However, the animal welfare implications of this case must be very carefully considered because this calf has been lame for 3 months without decisive action. Attempting to fatten the animal will not be successful because the animal is already poorly grown and spends much of its time lying down; isolation will reduce competition for feed but will not necessarily increase intake. While radiography may be seen as an unnecessary expense by the farmer, the veterinary surgeon's constant endeavour is the health and welfare of animals committed to his/her care, not the farm's profitability. No other calves were affected and the cause of the hip dysplasia was not determined.

CASE 1.54

1 Why would the farmer apply hobbles? Obturator nerve and sciatic nerve injuries (L6) result in adductor paresis in newly calved animals. Hip-lock during anterior presentation of the calf is the most common cause of adductor paresis. Severe abduction (‘doing the splits') can also occur when the cow loses her footing on wet slippery surfaces. Hobbles are a crude but effective means of restricting abduction for a short period of time. Husbandry measures are also essential such as non-slip walking surfaces (1.54b, where the cow is bedded on deep straw), housing the animal in a small group to reduce competition at the feed bunk and milking at the end to prevent bullying.

2 Are the hobbles fitted correctly? Hobbles should be placed just above the cow's fetlock joints (1.54b) and checked regularly for skin abrasions. Inflatable cushions, webbing nets and swim tanks can all be used in the animal's rehabilitation, but the

amount of time on busy commercial dairy farms is rarely adequate for such individual animal care.

3 How long should hobbles remain in place? Hobbles should only be necessary for 7-10 days and should not be left on for as long as 2 months, as was the case in this heifer.

4 How could the risk of this problem be reduced? Avoid excessive traction during calf delivery. Avoid sharp corners and wet slippery walking surfaces, especially for recently calved cows.

CASE 1.55

1 What conditions would you consider (most likely first)? Cerebral abscess; congenital abnormality such as hydanencephaly or hydrocephalus; polioencephalomalacia; vitamin A deficiency; lead poisoning; closantel toxicity.

2 What tests would you undertake? A provisional diagnosis of cerebral abscess is based on chronicity of the condition, insidious onset and lack of other clinical signs suggestive of particular toxicities. A lumbar CSF sample collected in the standing animal under local anaesthesia failed to reveal any abnormality; however, this is not an unusual finding in cerebral abscess cases and a normal sample should not rule out this possibility.

3 What treatment would you administer? The calf was treated daily with procaine penicillin for 3 weeks without improvement. The decision was taken to euthanase the calf due to the 3 months’ duration of altered behaviour and failure

to respond to treatment; necropsy revealed hydrocephalus (1.55b). The cause of the hydrocephalus was not determined but clinical signs would probably have been present from birth (congenital lesion) and not been noted by the farmer. It is possible that the hydrocephalus resulted from a developmental lesion, but this could not be determined. No similar cases had occurred on this farm nor were there any in the following 3 years.

CASE 1.56

1 What conditions would you consider (most likely first)? Hypomagnesaemia; lead poisoning; urea/nitrate poisoning.

2 What treatment would you administer immediately? While unlicensed for use in cattle, 8 ml of 20% pentobarbitone sodium solution injected IV as a bolus controls seizure activity a great deal more effectively than either diazepam or xylazine. Within 30 seconds the seizure activity is controlled and 50 ml of 25% magnesium sulphate added to a bottle

of 400 ml of 40% calcium borogluconate solution is given by slow IV injection over 10 minutes. The remaining 350 ml of the bottle of 25% magnesium sulphate solution is given SC in two divided sites immediately behind the shoulder. The cow was able to maintain sternal recumbency when pulled upright after all the treatments had been administered and walked off to find its calf after a further

20 minutes.

3 What samples would you collect to confirm your diagnosis? A serum sample for magnesium concentration was collected before treatment but was not analysed because of the good response (1.56b).

4 What control measures could be adopted for the rest of the herd? It is unusual to encounter hypomagnesaemia during the summer months (absence of stormy weather and no lush pasture). It is possible that bulling behaviour had interrupted grazing patterns and reduced feed intake over the previous 12-24 hours. General recommendations are to feed at-risk cattle up to 2 kg per head per day of high magnesium concentrates and good quality barley straw, but it unlikely cattle would eat these feeds when there is a good supply of grass. No management changes were adopted and no further cases occurred during the remainder of the grazing season. Ad-libitum minerals are often provided to cows at pasture but there is no convincing evidence that this measure prevents hypomagnesaemia.

CASE 1.57

1 What conditions would you consider (most likely first)? Infectious bovine keratoconjunctivitis (IBK); foreign body (e.g. grass awns) within the conjunctival sac; bovine iritis; infectious bovine rhinotracheitis. With IBK, spontaneous recovery starts in mild cases 3-5 days after clinical signs are first observed, and is complete

2 weeks later. In severe cases, ulceration may progress to corneal perforation and panophthalmitis but this is uncommon.

2 What treatment would you administer? Topical ophthalmic antibiotic cream containing cloxacillin is commonly used by farmers. Antibiotic injection (penicillin, oxytetracycline or ceftiofur) into the dorsal bulbar conjunctiva is the best treatment but can be difficult to achieve in fractious adult cattle and requires good restraint. Injection into the upper palpebral conjunctiva is commonly used, but it should be noted that this technique will not give residual antibiotic levels in the eye and relies on leakage onto the cornea from the injection site. This technique has no advantage over systemic injection, except for the much lower cost because of the smaller antibiotic dose. When subconjunctival or topical treatment is not practical, single dose long-acting oxytetracycline, florfenicol, tilmicosin or tulathromycin have all been reported to be effective.

Metaphylactic injection of all at-risk cattle with a single IM injection of long- acting oxytetracycline or tilmicosin could be considered in severe epidemics, but there are no supporting field data.

3 What action would you take? Outbreaks of IBK may occur after the introduction of purchased stock, therefore whenever possible, all new stock should be managed separately as one group away from the main herd. Fly control can be attempted using impregnated ear tags and pour-on insecticides, but these are often of short duration and repeated treatments can prove relatively expensive. Development of immunity following infection is variable and recurrence is common.

CASE 1.58

1 What conditions would you consider (most likely first)? Include: infectious bovine rhinotracheitis (IBR); pasteurellosis; recrudescence of chronic suppurative pneumonia.

2 How would you confirm your diagnosis? Ocular swabs (vigorous action to obtain cellular material) for a FAT and PCR for IBR. Paired serology would involve 2 weeks' delay but could be undertaken because the bull was from an IBR-accredited herd and had not been vaccinated.

3 What treatment(s) would you recommend? The farmer was advised to vaccinate all cattle immediately with an intranasal IBR vaccine. The bull was treated with procaine penicillin (44,000 IU/kg IM for 3 consecutive days) and was much improved the following day.

4 What control measures could be adopted for future years? IBR vaccination (and possibly BVD and leptospirosis vaccination) on arrival on the farm is very effective and introduced cattle should be quarantined for at least 2-4 weeks after arrival.

CASE 1.59

1 What conditions would you consider (most likely first)? Include: inhalation pneumonia; septic pericarditis; chronic suppurative respiratory disease exacerbated after calving; pleurisy; hepatocaval thrombosis; endocarditis.

2 What tests would you undertake? Real-time B-mode ultrasonographic examination of the right chest with a 5 MHz sector scanner reveals normal lung surface and no distension of the pericardium. On the left side there is normal lung in the dorsal third of the chest replaced ventrally by an extensive anechoic area containing multiple hyperechoic dots typical of a pleural abscess/pyothorax extending at least 12 cm from the chest wall. These sonographic findings, in addition to the tinkling/splashing sounds, are consistent with a diagnosis of unilateral inhalation/necrotising pneumonia progressing to pyothorax. The unilateral nature of the lesion, presumably because the cow was recumbent on that side, would explain how the cow was still alive.

3 What treatment would you recommend? The extensive nature of the pyothorax lesion (1.59b) and destruction of the left lung (1.59c) means that treatment would be ineffective and the cow was euthanased for welfare reasons. Drainage of the pyothorax could be attempted in addition to an extended treatment regime of penicillin (and metronidazole where licensed), but this would be a salvage procedure only and cannot be justified for welfare reasons.

4 How could this condition have been prevented? Prevention of the hypocalcaemia by calculating the dry cow ration based on dietary cation anion balance, together with prompt treatment, would have prevented this case occurring. Other causes of inhalation pneumonia include incorrect drenching technique, especially in hypocalcaemic cows with temporary loss of the swallow reflex.

CASE 1.60

1 What conditions would cause weight loss and diarrhoea (most likely first)? Include: Johne’s disease (Mycobacterium avium var paratuberculosis; MAP); chronic fasciolosis; chronic salmonellosis; chronic bacterial infection leading to debility.

2 What further tests could be undertaken? The ELISA test specificity is 97% but the sensitivity of this test is low until the latter stages of disease. If the clinical signs are suggestive of Johne’s disease but the first sample proves negative, quarantine the animal and retest in 4-6 weeks. PCR testing of faeces is generally undertaken where serology is positive but the cow shows no clinical signs. Culture of MAP from faeces takes 4-6 weeks. At necropsy, acid-fast bacteria can be demonstrated both within the gut wall and ileocaecal lymph nodes in cattle with Johne’s disease. Cattle with patent fasciolosis pass eggs in the faeces, although numbers may be low due to the host’s immune reaction.

3 Why is the calf much smaller than other calves in the group? The calf suffered from chronic intrauterine growth retardation as a consequence of poor dam protein status caused by leakage across the diseased intestines (protein-losing enteropathy).

4 What is the prognosis for the calf? The calf is highly likely to have already been infected with MAP from transplacental infection, via contaminated colostrum and milk, and a highly contaminated environment considering the dam is in the advanced clinical stage of disease and has profuse diarrhoea. While the incubation period for clinical disease is typically 4-5 years, clinical disease leading to emaciation is not uncommon in cattle as young as 15-18 months (1.60b). It is generally assumed that such early mainfestation of clinical signs is a consequence of massive challenge,

usually from a dam in the agonal stage of disease (this case). Against veterinary advice, the farmer fostered this calf onto another cow whose calf had died. This action will simply lead to environmental contamination and greater risk of disease dissemination and the possibility that the animal will succumb to clinical disease before reaching slaughter weight at 15-18 months.

CASE 1.61

1 What is your diagnosis? LDA. The LDA occupies the craniodorsal area of the left side of the abdominal cavity where auscultation and succussion reveal high- pitched ‘tinkling’ sounds. There is also evidence of (secondary) ketosis.

2 What other conditions could cause tympany in this area? Rumen void, which refers to the gap caused by the shrunken rumen falling away from the left abdominal wall; gas cap in the rumen associated with ruminal atony, acidosis, grain overload, etc.; pneumoperitoneum is rare.

3 What action would you take? There are numerous treatment options:

• Rolling the cow to correct the LDA has been practised but requires three people, is as time consuming (therefore as costly) as surgery, and less than 40% successful.

• A Grymer/Sterner blind toggle suture is not without risk if the operator is inexperienced in this technique.

• Corrective surgery is best performed in the standing cow under distal paravertebral analgesia. A right laparotomy incision is made and the abomasum deflated using a 14 gauge needle connected to a flutter valve. On release of gas, the abomasum slowly sinks towards the ventral midline, pulled by its liquid contents. The greater omentum is grasped by the surgeon’s right hand and carefully pulled around to the ventral mar­gin of the right laparotomy inci­sion. An omentopexy (1.61b) or pyloropexy is performed whereby a continuous suture taking four 4-5 cm bites of omentum or pylorus is continued to close the peritoneum and internal oblique muscle layer. The laparotomy wound is closed routinely.

4 What treatment(s) would you administer? Treatment for the secondary acetonaemia comprises an IM injection of dexamethasone and 400 ml of 50% dextrose administered IV. Propylene glycol can be administered orally.

CASE 1.62

1 What conditions would you consider? Lice (pediculosis); forage mites; sarcoptic mange; chorioptic mange; bovine besnoitiosis, a vector-transmitted disease caused by the protozoan parasite Besnoitia besnoiti, is not present in the UK.

1 Cattle: Answers

2 What further tests could be undertaken? Inspection of the skin reveals extensive louse infestation. Microscopic examination of skin scrapings reveal numerous chewing (round mouthparts; Damalinia bovis) and sucking lice (narrow and more pointed mouthparts; Linognathus vituli.).

3 What actions/treatments would you recommend? Treatment options include pour-on pyrethroid (e.g. cypermethrin) compounds that effect rapid improvement but may require repeat treatment in 2-4 weeks. All in-contact cattle must be treated. Injectable group 3 anthelmintics (macrocyclic lactones, including avermectins and milbemycins) are not always wholly effective against chewing lice and pour-on formulations should be used; however, this is an expensive option because anthelmintic treatment is not necessary. Furthermore, use of a group 3 anthelmintic may increase the selection pressure for resistant parasite strains, including gastrointestinal parasites.

Pediculosis is widespread in all beef herds and routine treatment is recommended at housing. Interestingly, bulls are invariably more severely affected than cows.

4 Are there any consequences of this problem? Disruption to grazing/feeding may cause reduced liveweight gain/loss of body condition in severe infestations, although very heavy burdens are more often a consequence rather than the cause of debility. Anaemia as a consequence of severe louse infestations is rare.

CASE 1.63

1 Describe the sonogram. There is a well-encapsulated 2 cm diameter abscess immediately beneath the capsule with adherent small intestine wall. There are five more 3-8 cm diameter abscesses detected throughout the liver (not shown).

2 What conditions would you consider (most likely first)? Include: liver abscessation; liver abscessation and localised adhesions involving small intestine.

3 What treatment would you recommend? The liver abscesses appear well- encapsulated and are not sufficient in size or number to cause a significant effect, although it is not possible to examine all of the liver, particularly where

it is in contact with the diaphragm. Continue the course of penicillin for a further 10 days.

The cow failed to improve despite treatment and was culled. Necropsy revealed focal peritonitis with adhesions between the liver capsule and small intestine (1.63b), where there is considerable fibrin deposition on the liver surface.

CASE 1.64

1 What conditions would you consider (most likely first)? Lungworm (Dictyocaulus viviparus) challenge; fog fever; IBR; BRSV; influenza A; bluetongue.

2 What laboratory tests could be undertaken to confirm your provisional diagnosis? Larval challenge in susceptible adult cattle results in clinical signs typical of lungworm infection, but the challenge may not yet be patent (Baermann technique - negative).

3 What treatment would you administer? Remove cattle from the contaminated pastures. Prompt anthelmintic treatment is essential. Some cattle may have a protracted convalescence.

4 What control measures would you recommend? Vaccination of calves before their first grazing season confers life-long immunity in most situations unless severely challenged as adults. Avoid grazing cattle on potentially heavily contaminated pastures. Alternate annual grazing with sheep where possible.

CASE 1.65

1 What conditions would you consider (most likely first)? Malignant catarrhal fever (MCF); mucosal disease; severe IBR; listerial iritis; bluetongue; foot and mouth disease.

2 How could you confirm your suspicions? Diagnosis is based on clinical signs and confirmed by demonstration of MCF virus by PCR, antibodies in serum and/or characteristic postmortem findings. Only one animal affected in the group would exclude many diseases (e.g. IBR, bluetongue and foot and mouth disease).

3 What treatment would you administer? There is no treatment for MCF and affected cattle must be euthanased immediately for welfare reasons. High doses of corticosteroids given systemically may give temporary improvement of clinical signs in a small number of mild cases, but these recovered cattle never thrive.

4 List any preventive/control measures. MCF is caused by ovine herpesvirus-2. Contact with periparturient sheep or goats appears necessary for transmission to cattle and deer, although several months may elapse between such contact and overt disease (2 months in this case). A sheep flock may have a high seroprevalence but the method of transmission to cattle remains unknown. Cattle do not transmit MCF. Control relies on avoiding contact with sheep, but such management is not possible on most mixed stock farms.

CASE 1.66

1 What conditions would you consider? Bacterial meningoencephalitis; septicaemia.

2 How could you confirm your diagnosis? Diagnosis of meningoencephalitis follows lumbar CSF collection under local anaesthesia using a 20 gauge 1 inch hypodermic needle. Samples are usually collected with the calf positioned in sternal recumbency, but can easily be collected when the calf is in lateral recumbency (this

case). The collected sample is turbid, caused by the influx of white cells, and has a frothy appearance visible after sample agitation due to the increased protein concentration (1.66b). Laboratory analysis reveals a total protein concentration of 1.9 g/l (19 mg/dl) (normal 55 g/l [5.5 g/dl] are often quoted).

3 What is the likely cause? Escherichia coli is the most common isolate from septicaemic calves but Pasteurella spp., Staphylococcus pyogenes and Trueperella pyogenes have been isolated from clinical cases of meningoencephalitis.

4 What treatment(s) would you administer? The calf was treated with IV marbofloxacin and soluble corticosteroid (dexamethasone, 1.0 mg/kg) but failed to improve and was euthansed for welfare reasons 6 hours later.

5 What recommendations would you offer? This condition arose due to failure of antibody transfer plus a contaminated calving pen. The calving was assisted late at night and the calf unsupervised until morning. In this situation either the farmer milks colostrum from the cow immediately or uses stored frozen then thawed colostrum from another cow (3-2-1: 3 litres, first 2 hours of life, first milk).

CASE 1.67

1 How could effective analgesia be achieved? The calf is injected with flunixin meglumine or other NSAID IV. Effective analgesia after lumbosacral extradural injection of 3 mg/kg of 2% lidocaine solution allows a detailed and pain- free clinical examination of hind leg joint lesions and fractures, and presents a cheap and readily available alternative to general anaesthesia. Injectable general anaesthetic drugs such as alphaxalane or propofol may be considered prohibitively expensive. Administration of xylazine (0.1 mg/kg IM) followed by administration of ketamine (2-3 mg/kg IV) is commonly used in practice.

2 What action would you take? Reduce the fracture under extradural block and apply a fibreglass cast.

3 What is the likely prognosis? The prognosis for metatarsal fracture is generally good. The cast was removed after 5 weeks when the fracture had healed well and the calf was not lame.

CASE 1.68

1 What conditions would you consider (most of the nasal cavity; ethmoid carcinoma; nasal osteomyelitis of the hard palate; advanced erosive fungal sinusitis.

2 What further tests could be undertaken? Rhinoscopy reveals a large >5 cm mass occupying the ventral meatus (1.68b).

3 What action would you take? There is no evidence of metastasis to the drainage submandibular lymph nodes and squamous cell carcinomas do not usually spread beyond the local drainage lymph nodes. Immediate slaughter for human consumption is the best course of action in this case. Surgical removal is possible but unrealistic and not in the animal's best interest.

likely first)? Squamous cell carcinoma lymphosarcoma; nasal osteosarcoma;

CASE 1.69

1 What conditions would you consider (most likely first)? Necrotic enteritis; mucosal disease; salmonellosis; coccidiosis.

2 How could you confirm your suspicions? Diagnosis is based on exclusion of other diseases and confirmed at necropsy, as the prognosis is grave. Mucosal disease is possible but unlikely in such a young calf. Coccidiosis, caused by Eimeria alabamensis, is usually a group problem. Typical, although non-diagnostic, haematological findings in this disease are anaemia (variable in its severity) and leucopenia caused by a severe non-regenerative neutropenia. Many affected calves have high blood urea concentrations associated with kidney pathology.

3 What necropsy findings would confirm your suspicions? Ulcers often overlain by necrotic debris and secondary fungal infection may occur in the larynx, rumen, abomasum and small and large intestines, extending as far as the rectum. The ulcerative lesions vary from small discrete punctate lesions to large linear diphtheritic plaques overlying Peyer's patches (1.69b). The ulcers may be full thickness, leading to areas

of localised peritonitis on the serosal surface with adhesions to adjacent gut. The kidneys often appear swollen and pale with infarcts. Inhalation pneumonia is often seen in association with severe pharyngeal and laryngeal diphtheresis.

4 List any preventive/control measures. As the cause remains unknown, there are no specific control measures.

CASE 1.70

1 Describe the sonogram. There is evidence of the right kidney, extending from the abdominal wall for 2-3 cm only, containing several small anechoic areas, possibly part of the renal pelvis, but this structure is poorly defined. Distal to this structure is a 5-6 cm diameter, well-encapsulated uniform mass.

2 What could this structure represent? Nephroblastoma; perirenal abscess.

3 What action would you take? No other reason for poor growth in this calf was found on clinical examination. The calf was too small to attempt to palpate/ image the left kidney per rectum. Due to the poor prognosis the calf was euthanased for welfare reasons and the diagnosis of nephroblastoma confirmed at necropsy (1.70b). The left kidney was normal; it was not possible to explain why the nephroblastoma caused poor growth or whether it was simply a coincidental finding.

CASE 1.71

1 What conditions would you consider? Osteochondrosis is caused by abnormal differentiation of cells in growing cartilage and can progress to osteochondritis dissecans, with impaired vascularisation of articular cartilage leading to necrosis and fragmentation of cartilage. Some degree of joint effusion of the hock joint is very common in many beef bulls. It may be due to a mild osteochondrosis lesion that never progresses to osteochondritis dissecans and thus causes little or no lameness.

2 Is this bull fit for sale as a breeding bull? Diagnosis of osteochondritis dissecans is based on the presence of considerable joint effusion in association with chronic mild

to moderate lameness. Radiography may confirm the presence of calcified flaps free within the joint (‘joint mice'), but such identification is not easy. Diagnosis is confirmed at necropsy in bulls that remain so lame as to prevent natural service (1.71b).

3 How could this problem be reduced/prevented? Less emphasis should be placed on achieving maximum growth rate to sale in beef bulls, but this parameter features highly in estimated breeding values. Start breeding when the bull is fully mature at around 2 years old.

CASE 1.72

1 What are the important sonographic features seen in the sonogram? There is a thick-walled (1-1.5 cm) umbilical abscess (anechoic area containing multiple hyperechoic dots), extending to 4 cm diameter, to the right of the sonogram. In the centre there is a poorly defined 4 cm diameter anaechoic area containing fine hyperechoic lines. This area represents localised accumulation of peritoneal fluid with fibrin tags (exudate), consistent with localised peritonitis. Normal intestine is visible distal to this accumulation of exudate and to the left side of the image. The ultrasound findings are suggestive of a focal peritonitis associated with an umbilical abscess.

2 What action would you take? The cause of the abscess and associated peritonitis was thought to be Trueperella pyogenes, but no samples were taken for culture. The calf was treated with a 14-day course of daily penicillin injections (time-dependent action) and made an uneventful recovery. AmoxycillinZclavulanic acid combination could also have been used but is considerably more expensive. The abscess was not lanced at the initial veterinary visit because of its thick wall and adjacent, and possibly adherent, intestine. Furthermore, the well-encapsulated abscess was considered to be much less significant than the peritonitis. The good response to antibiotic therapy was surprising because peritonitis lesions from umbilical infections in young calves can form adhesions between loops of intestines, blocking flow of digesta (1.72b) and leading

to severe consequences of collapse, toxaemia and death. The diagnosis of focal fibrinous peritonitis was based on the ultrasound examination; had this scanning not be undertaken then the full extent of the problem would not have been identified. The examination took less than 5 minutes, but allowed a more accurate diagnosis.

CASE 1.73

1 What conditions would you consider (most likely first)? Include: type I ostertagiosis; copper deficiency; poor pasture management; transient BVDV infection (persistently infected animal added to naive group).

2 What further tests could be undertaken? Modified McMaster technique for strongyle eggs. Either count 4-6 individual samples or pool together. Examination revealed individual counts from 800 to 1,400 strongyle eggs per gram of faeces in four animals. Low serum copper concentrations samples from 4-6 calves would indicate depletion of liver copper reserves - normal values were recorded in this investigation.

3 What treatment(s) should be administered? Treatment with an injectable avermectin anthelmintic effected a good response (cessation of diarrhoea within a few days) and provided protection against reinfestation for the remainder of the summer grazing period (cattle housed 3 weeks later).

4 Could this problem(s) be prevented next year? Parasitic gastroenteritis control on contaminated pasture requires strategic anthelmintic treatment including intraruminal pulse release boluses (benzimidazole every 3 weeks), ivermectin injections 3, 8 and 13 weeks after turnout, doramectin injections at turnout and 8 weeks later, or doramectin slow release injection at turnout. Where there is a known risk, lungworm is best prevented by vaccination 2 and 6 weeks before exposure.

CASE 1.74

1 What are the potential benefits and risks?

Benefits:

• Much reduced environmental pathogen challenge, provided good weather and a sufficiently large field, which should reduce cryptosporidi­osis problem but requires good handling facilities nearby.

• Easier to identify first stage labour - cow isolates herself from the group.

• Reduced bedding and medicine costs.

Risks:

• Time-consuming to check all cows in a large field, especially during the 9-10 hours of darkness.

• May prove difficult to attend to calving problems and get cow into han­dling facilities, especially at night.

• May prove difficult to treat the calf's umbilicus soon after birth, although far fewer problems are encountered when calving outdoors.

• May encounter problems with catching and tagging calves, especially if aggressive dam.

• Hypothermia of newborn calves during severe weather.

CASE 1.75

1 Describe the abnormal radiographic findings. There is a fracture of P1.

2 What action should be taken? The calf was sedated with xylazine and short duration general anaesthesia induced with 3 mg/kg ketamine IV. The fracture was reduced by realigning the lateral deviation of the distal leg (see 1.75a) and a fibreglass cast applied. The calf was sound after a few days and the cast removed after 1 month. The calf made an uneventful recovery and is shown 6 months later (1.75b). Fracture of P1 presumably resulted from torsional forces applied to the sole remaining digit of that foot. This author has seen only one other case of P1 fracture following digit amputation in the same foot in 37 years of farm animal practice.

Other causes of lameness after digit amputation include cellulitis involving the incision site and osteomyelitis of the P1 stump.

CASE 1.76

1 What conditions would cause such weight loss and diarrhoea (most likely first)? Include: Johne's disease (Mycobacterium avium paratuberculosis; MAP); chronic salmonellosis; chronic bacterial infection leading to debility/amyloidosis.

2 What further tests could be undertaken? The cow tested positive on ELISA for paratuberculosis. The ELISA test specificity is 97%, but the sensitivity of this test is low until the latter stages of disease. If the clinical signs are suggestive of Johne's disease but the first sample proves negative, quarantine the animal and retest in 4-6 weeks. PCR testing of faeces is generally undertaken where serology is positive but the cow shows no clinical signs. Culture of MAP from faeces takes 4-6 weeks. At necropsy, acid-fast bacteria can be demonstrated both within the corrugated small intestine (1.76b, left side; normal gut on right side) and ileocaecal lymph nodes in cattle with Johne's disease.

3 What control measures could be adopted? A test and cull policy could be adopted after a whole herd screen to determine the true prevalence of paratuberculosis. If the seroprevalence is high, then whole herd slaughter and restocking may be the most cost­effective programme, but few beef farmers are able to embark on such a strategy. There are no guidelines for a whole herd culling policy but a seroprevalence of >15-20% would

warrant serious consideration. There are several problems with the test and cull policy, not least the cost of annual testing, but also the low test sensitivity and less than 100% specificity (see above).

Vaccination against Johne’s disease prevents overt disease but is not an option for many beef farmers because replacement heifers are typically bought as either yearlings or in-calf heifers, while vaccination has to be undertaken within the first 2 weeks of life. Disadvantages of a vaccination policy include a granulomatous reaction at the injection site, cost, interference with the comparative intradermal

tuberculin test and trade/export restrictions.

CASE 1.77

1 What conditions would you consider (most likely first)? Proximal duodenal obstruction; retroflexed caecum; intestinal torsion; peritonitis; intussusception.

2 What further tests would you undertake? Ultrasonography provides immediate results of the peritoneum and viscera to the depth of 20 cm from the abdominal wall for most 5 MHz sector scanners (10 cm for 5 MHz linear scanners). Particular attention should be paid to fluid distension (>5-7 cm) of lengths of intestines, with reduced peristalsis suggestive of an obstruction. This fluid also appears more uniformly anechoic rather than containing multiple hyperechoic dots typical of normal digesta.

Abdominocentesis should be guided by ultrasound findings. Demonstration of an inflammatory exudate with a high protein concentration and an increased white cell count with predominance of leucocytes is indicative of peritonitis. However, peritonitis localised by the omentum is not a simple diagnosis because infection can be contained within the omentum and therefore cannot always be sampled by abdominocentesis.

3 What action would you take? In this case, fluid-filled intestines (duodenum) were identified ultrasonographically in the lower right cranial quadrant, suggestive of a duodenal obstruction. At surgery a thin ‘thread-like’ taut fibrinous band was

found on the serosal surface, constricting the duodenum. As this constriction was at arm’s length from the right flank laparotomy site, it was snapped between the surgeon’s fingers. The bull made a full recovery. The cause of the constricting fibrinous band was not identified.

CASE 1.78

1 What conditions would you consider (most likely first)? Hepatocaval thrombosis; chronic suppurative pulmonary disease; nasal tumour; sinusitis; endocarditis.

2 How can you confirm your provisional diagnosis? Epistaxis is considered to be the cardinal clinical sign of advanced hepatocaval thrombosis. Diagnosis of hepatocaval thrombosis is very difficult and is often based on exclusion of more common/likely conditions. Ultrasonographic demonstration of a thrombus present in the caudal vena cava can be achieved in some cases, but such examination is rarely undertaken in general practice. Ultrasonographic examination of the chest would rule out chronic suppurative pneumonia. Bacteraemic spread from the thrombus often forms foci deep within the lung parenchyma, which do not involve the visceral pleura and therefore cannot be imaged. Endocarditis cases often have an increased and irregular heart rate (>100 beats per minute) but normal heart sounds without an audible murmur.

3 What treatment would you administer? Once arterial bleeding occurs there is damage to the wall of a major blood vessel, which cannot be repaired. Theoretically, procaine penicillin injected daily for at least 6 weeks may overcome the bacteraemia, but will not remove the massive thrombus within the vena cava such that further bacterial shedding is likely.

4 What action would you recommend? Emergency slaughter on farm is likely to be ill-advised because the cow is in poor condition and there is likely to be foci in the liver, lungs and kidneys, which may result in carcass condemnation. Necropsy findings typically include chronic venous congestion leading to hepatomegaly and a ‘nutmeg appearance’. The cow should not be transported to a slaughter plant because it may bleed out at any time. The best action is to shoot the animal for welfare reasons. At necropsy, liver abscesses are common adjacent to the vena cava and extending into the lumen (1.78b), seeding the lungs and other organs.

CASE 1.79

1 What conditions would you consider (most likely first)? Pedal bone fracture extending to involve the articular surface. Careful examination of the foot has eliminated other more common causes of lameness including white line abscess.

2 What action would you take? A wooden block applied to the sound claw relieves lameness and the prognosis is very good where the fracture does not involve the articular surface. However, the prognosis in this bull is guarded. Unfortunately, no follow up is available for this bull.

CASE 1.80

1 Describe the important features of the sonogram obtained at the sixth intercostal space using a 5 MHz sector scanner (1.80a). Ultrasound examination reveals purulent material (5-6 cm anechoic area with multiple hyperechoic dots) distending the pericardial sac. There is fibrin deposition on the epicardium (broad irregular hyperechoic band) and oedema of the myocardium (narrow anechoic band underlying the fibrin deposits). These findings are consistent with a diagnosis of septic pericarditis (1.80b).

2 What treatment would you administer? There is no effective treatment and the cow should be euthanased immediately for welfare reasons. While ‘pericardial strips’ have been described, it is clear from the necropsy image that removing the pericardium will not be successful due to the large amounts of fibrin deposited on the epicardium. Such surgery is rarely, if ever, justified.

3 Could this situation have been

prevented? Septic pericarditis occurs in some cases of traumatic reticulitis following penetration of the pericardial sac by a sharp metal object. Prompt detection of traumatic reticulitis cases would permit removal of the wire, but sometimes the wire passes through to the pericardium very quickly, as evidenced by the lack of significant peritoneal reaction. Routine administration of magnets to lodge within the reticulum is practised in herds with a history of ‘hardware disease’ to attract and bind ingested metal objects.

CASE 1.81

1 Describe the important sonographic findings. Transabdominal ultrasonographic examination reveals fluid distension of loops of the caecum (estimated to be approximately 20 cm in diameter), with large amounts of fibrin on the serosal surfaces. The caecal wall appears oedematous.

2 What further tests might you undertake? Ultrasound-guided abdominocentesis could be undertaken but the peritoneal fluid is an inflammatory exudate, as evidenced by the large amounts of fibrin.

3 What action would you take? There is severe localised peritonitis involving the wall of the caecum, with fibrinous adhesions between adjacent loops. The prognosis is hopeless and the cow was euthanased immediately. Necropsy confirmed the severe localised fibrinous peritonitis (1.81b).

4 Comment on the value of an exploratory laparotomy in this case. There was no indication for an exploratory laparotomy in this case because transabdominal

ultrasonography had clearly indicated

the severity of the fibrinous peritonitis (see 1.81a). The cost and, more importantly, the unnecessary surgery cannot be justified in this case. A more thorough investigative approach obviates the need for ‘heroic’ last ditch exploratory surgery, which is rarely, if ever, successful.

CASE 1.82

1 What conditions you would consider (most likely first)? Septic pericarditis; dilated cardiomyopathy; pleural effusion associated with either thymic lymphosarcoma or end-stage farmer’s lung.

Ultrasonography revealed massive distension of the pericardial sac extending half way up the chest wall on both sides and containing fibrinous exudate.

2 What treatment would you recommend? There is no effective treatment and the cow was euthanased for welfare reasons. The extent of the pathology was revealed at necropsy (1.82b).

3 What recommendations would you make? Attention to storage of car tyres used on top of silage sheets. Use of prophylactic magnets in the cow's reticulum. Bonfire sites can be a source of sharp metallic objects.

Septic pericarditis is a common sequela to traumatic reticuloperitonitis. While surgery to remove sharp metallic objects from the reticulum was common in veterinary practice 30 years ago, these cases are no longer detected at an early stage and have progressed to septic pericarditis before veterinary attention is requested on farm. As a consequence, septic pericarditis is a common cause of culling/ fatality on both beef and dairy farms. One explanation may be that farmers delay requesting veterinary attention until the next routine visit (often every 1-2 weeks). Some large farms have standard operating procedures with respect to treatments for various clinical presentations; this further delays veterinary examination and surgery to remove the wire while it is still within the reticular wall. Traumatic reticuloperitonitis is one of the few conditions that results in a dramatic reduction in milk yield and appetite; farmers must present such cases that day and not delay, otherwise the consequences are usually fatal.

CASE 1.83

1 What conditions would you consider (most likely first)? Localised peritonitis; endocarditis; pleurisy; recrudescence of chronic suppurative pulmonary disease; liver abscessation.

2 What furthers tests would you undertake? Diagnosis of localised peritonitis can be made following abdominocentesis and demonstration of an inflammatory exudate with a high protein concentration and an increased white cell count with a predominance of leucocytes. However, localised peritonitis is not a simple diagnosis because infection can be contained within the omentum and therefore cannot always be identified by abdominocentesis. In addition, the needle point may enter fibrin deposited on serosal surfaces in many cases. A positive belly tap and therefore probably involves the abomasum rather than the reticulum. Five MHz linear scanners are also extremely useful - do not be distracted by their 10 cm range, as 7 cm of exudate is significant (3 cm depth of body wall). Once again, be aware of omental bursitis, which cannot be identified by transabdominal ultrasonography because the infection is enveloped by the omentum and cannot be imaged.

result is diagnostic, but remember the limitations if no sample or indeed a normal transudate is obtained.

Transabdominal ultrasonography provides immediate results of the peritoneum and viscera to the depth of 20 cm for most 5 MHz sector scanners and is most useful for examination of the anterior abdomen. An inflammatory exudate with extensive fibrin tags is shown (1.83b) in the right cranial abdomen

3 What treatment would you administer? Parenteral antibiotic therapy is hopeless in all but very localised cases of peritonitis and is often undertaken in those situations where there has been only limited investigation with the expectation that the animal is suffering from another infectious disease.

4 What action would you take? Because antibiotic therapy is rarely successful in diffuse peritonitis cases, the animal should be euthanased for welfare reasons.

CASE 1.84

1 What conditions would you consider (most likely first)? Primary photosensitisation and dermatophilosis.

2 What are the possible causes? Primary photosensitisation occurs when preformed photodynamic agents are absorbed from the gut. Hepatogenous (secondary) photosensitisation results from liver disease and the inability to excrete phylloerythrin, a metabolite of chlorophyll. Liver disease and secondary photosensitisation can be caused by the ingestion of mouldy feed containing aflatoxins and from chronic liver fluke infection (there was no history of liver fluke on this farm and faecal sedimentation results were negative).

3 What advice would you offer? The cow should be housed to protect it from direct sunlight. Systemic corticosteroids may be indicated in the acute erythematous stage of photosensitisation to prevent extensive inflammation and necrosis, but this stage had long passed and the cow was 6 months pregnant (risk of abortion). Topical emollients and antibiotics may help soften and protect the skin but are not commonly used.

CASE 1.85

1 List four important observations. (1) The cow has an arched back consistent with severe lameness. (2) The cow has an extreme plantigrade stance of both hind feet (right hind foot more obvious with the accessory claws almost touching the ground). There is considerable swelling around the right hind fetlock joint. (3) The cow is in very poor body condition (BCS expected to reduce the size of a well-encapsulated abscess. Several other similar cases have responded well but further studies are necessary before any conclusions can be drawn from a small number of cases, but this treatment response is encouraging.

CASE 1.87

1 What conditions would you consider (most likely first)? Pregnancy toxaemia; severe chronic fasciolosis; metritis; hypocalcaemia.

Pregnancy toxaemia can occur during the last month of gestation in cows carrying twin calves fed a very low energy diet such as straw without supplementary feeding. This situation can occur in beef cows under severe drought/starvation conditions. Occasionally, fatty liver disease/pregnancy toxaemia results when farmers elect to drastically reduce feeding to over-conditioned pregnant beef cows after several dystocia cases in the group, mistakenly believing this regimen will reduce calving difficulties in the remainder; such abrupt energy reduction/starvation occurred in this case.

2 What tests would you undertake? Elevated serum ketone bodies (3-OH butyrate) and low plasma glucose concentrations support the clinical diagnosis. Markedly increased serum concentrations of liver enzymes, such as GLDH and GGT, and hypoalbuminaemia would reflect significant liver damage. Transabdominal ultrasound examination would reveal hepatomegaly (extending well beyond the costal arch). Further interpretation of liver ultrasound appearance is difficult because severe fatty change simply results in loss of normal liver architecture and can be difficult to differentiate from poor image quality.

3 What treatments would you administer? Recumbent cattle with pregnancy toxaemia (this case) should be destroyed for welfare reasons because the liver damage is so severe that recovery is not possible (1.87b). Less severely affected cattle could be treated symptomatically with oral fluids containing propylene glycol, IV multivitamin preparations, IV glucose, dexamethasone and antibiotics to treat septic metritis.

4 What control measures would you recommend? Provide adequate dietary energy (60-80 MJ/day) during late gestation with an extra 20 MJ/day for twin-bearing

cows and those in low body condition. Regular condition scoring of cows will detect weight loss. Ultrasound scanning during early pregnancy (weeks 5-14 after bull removed in a 9-week breeding season) identifies twin pregnancies, allowing grouping of these cows and correct nutrition.

CASE 1.88

1 What is the likely cause of such mortality? An 8-11% pre-weaning mortality rate has been quoted in several published surveys undertaken in the UK and the USA. The most likely cause of death is septicaemia and bacteraemic conditions, such as meningitis and polyarthritis, resulting from failure of passive antibody transfer. Umbilical infection leading to peritonitis is also a possible contributing factor. Losses due to septicaemia usually occur within the first 3-5 days; diarrhoea is an agonal finding.

2 How would you investigate this problem? Several methods can be used to determine passive antibody transfer; collection of plasma samples and measure of total protein concentration using a refractometer is by far the cheapest and allows a meaningful number of calves to be sampled as part of ongoing monitoring. Failure of passive transfer has been defined as a 55 g/l (5.5 g/dl) by 24 hours after ingestion indicates adequate colostrum ingestion. Necropsy of septicaemic calves may reveal only widespread petechial haemorrhages on serosal surfaces. A lumbar CSF tap is the best method to confirm meningitis, otherwise histopathology is required, as the gross appearance of congested blood vessels covering the brain is difficult to interpret.

3 What simple practical recommendations would you make? In simple practical terms, all calves must receive 3 litres of colostrum (first milking) within 2 hours of birth. Calves born within a large communal area may not find their dam and removal from the cow at birth to an individual pen and feeding colostrum by oesophageal feeder is the better option in a busy farm situation. There is debate whether a bottle and teat results in more effective antibody transfer, but this is overcome by feeding 3 litres. Feeding this volume also overcomes the problem of varying immunoglobulin concentrations in colostrum; estimating specific gravity using a ‘colostrometer’ can be helpful but is not essential. Feeding pooled colostrum depends on the herd paratuberculosis status because of the transmission risk for this disease, which is reaching endemic proportions in the UK and other countries. This potential problem can be overcome by installing a pasteurisation facility on the farm. The umbilicus of all calves should be immersed in strong veterinary iodine as soon as possible after birth of the calf.

CASE 1.89

1 What conditions would you consider (most likely first)? Puerperal metritis; toxic mastitis; salmonellosis; grain overload; concurrent LDA.

Puerperal metritis commonly affects cows after unhygienic manual interference to correct fetal malpresentation/malposture, after delivery of twins or a dead calf, and following infectious causes of abortion. In most of these situations, there is retention of some, or all, of the fetal membranes. Cows suffering hypocalcaemia during second stage labour have an increased incidence of retained fetal membranes and metritis. Bacterial entry and multiplication within the uterus produces toxins that are absorbed across the damaged endometrium. The likelihood of metritis increases in proportion to the duration of manual intervention in dystocia cases. The provisional diagnosis is based on history, clinical findings and elimination of other common diseases. Vaginal examination often stimulates discomfort and vigorous straining, and reveals copious amounts of red-brown foetid fluid.

2 What treatments would you administer? IV oxytetracycline and flunixin meglumine or a similar NSAID with IM oxytetracycline for the following 2-4 days. In toxic cows, rapid IV infusion of 3 litres of 7.2% hypertonic saline is indicated, with clean drinking water readily available. Thirty to 60 litres of warm water containing a variety of electrolytes, rumen stimulants and propylene glycol are often administered by stomach pump.

Retained fetal membranes should only be removed if they come away with gentle traction. Uterine lavage with several litres of warm sterile saline administered through the cervix using an orogastric tube has been suggested, with fluid and uterine detritus siphoned off by lowering the end of the tube to about the level of the udder. Care must be taken when attempting uterine lavage, as this technique may further damage a compromised uterine lining and promote further toxin absorption.

3 What follow-up treatment would you recommend? Observe closely as metritis/ twins are risk factors for LDA. The farmer is advised to present the cow for a pre­breeding check 21-28 days post calving when clinical endometritis, if present, can be treated with antibiotic wash-out or prostaglandin injection.

CASE 1.90

1 What conditions would you consider (most likely first)? Include: cystitis/ pyelonephritis; bladder tumour; chronic peritonitis.

2 How could you confirm your provisional diagnosis? Urinalysis reveals a strong positive result for protein, blood and white blood cells consistent with cystitis/ pyelonephritis. A direct smear of mid-stream urine sediment yields gram-positive rods. The BUN concentration is 14.9 mmol/l (41.8 mg/dl) (normal range 2-6 [5.6-16.8]). There is a slight leucocytosis (10.4 ? 10⁹/l [10.4 ? 10³/pl), resulting from a marginal neutrophilia. There is a marked hypoalbuminaemia and elevated globulin concentration (18.8 g/l [1.88 g/dl] and 61.3 g/l [6.13 g/dl], respectively), consistent with chronic bacterial infection.

Bacteriological culture of a urine sample yields a pure growth of Corynebacterium renale.

Transrectal ultrasonography using a linear scanner typically reveals a markedly thickened bladder wall (>1 cm). Transabdominal ultrasonography of the right kidney using a 5 MHz scanner reveals almost complete loss of normal kidney structure replaced by an irregular 6 cm diameter anechoic area containing hyperechoic dots consistent with a large abscess (1.90b). This appearance is consistent with pyelonephritis, with almost complete loss of normal kidney structure.

3 What is the prognosis? The prognosis for pyelonephritis is very poor due to the extent of kidney

destruction despite prolonged penicillin therapy. Some clinical improvement can be achieved in the short term in less severely affected cattle, which may allow slaughter. 4 What treatment would you recommend? Penicillin is excreted in the urine and is very effective against C. renale. Treatment should be administered IM once daily for 3-6 weeks. Unilateral nephrectomy has been described, but should be carefully considered; rarely does infection involve only one kidney and flank analgesia is wholly inadequate for such surgery.

CASE 1.91

1 Describe the important sonographic and necropsy findings. There is an extensive pleural effusion occupying the ventral half of the chest extending to 15 cm (1.91a). There is dorsal displacement of the lung with consolidation of its ventral margin caused by the amount of fluid within the chest (1.91b). There is no evidence of fibrin suggestive of an inflammatory exudate.

2 What are the possible causes? The most likely conditions to consider would include: (Holstein) dilated cardiomyopathy; right-sided heart failure caused by a space-occupying mass in the thorax (e.g. thymic lymphosarcoma or large mediastinal abscess); myocarditis.

There is no sonographic evidence of a distended pericardial sac suggestive of pericarditis. The lung surface appears normal with no evidence of chronic suppurative pneumonia or pleuritis. Hypoproteinaemia can result in peripheral oedema, but such an extensive pleural effusion would be rare.

3 What action would you take? Thoracocentesis could be undertaken to measure protein concentration and white cell concentration to confirm the fluid as a transudate. The heifer should be euthanased for welfare reasons. Holstein dilated cardiomyopathy affects 2-4-year-old animals where an inherited aetiology has been suggested. Diagnosis is based on exclusion of other possible aetiologies of right-sided heart failure, although an increased heart rate and dysrhythmia are common findings.

CASE 1.92

1 How would you correct this problem? The vaginal prolapse is replaced after

sacrococcygeal extradural injection of 5 ml of 2% lidocaine (procaine is not licensed for extradural injection). (Note: The needle should be advanced at 45°

to the (horizontal) vertebral column.) The prolapsed tissues are thoroughly cleaned in warm dilute antiseptic solution but it may not be possible to remove all faecal material. After waiting for 5 minutes after extradural injection, steady pressure is applied to the prolapsed tissues and they are easily replaced. A Buhner suture of 5 mm umbilical tape is placed in the subcutaneous tissue surrounding the vulva to retain the prolapse and pulled tight to approximately two fingers (1.92b). Antibiotic therapy may be advisable because of the faecal contamination of the vaginal mucosa, but there are no guidelines

based on field studies.

2 What is your advice regarding the management of this cow? The farmer is advised of the high probability of recurrence and the cow should be culled after she has reared her calf this year. Note that in natural mating systems cows can become pregnant despite the Buhner retention suture in situ. Should this happen, the suture must be slackened before the expected calving date. The suture can be retied after calving and passage of the fetal membranes. Vaginal prolapse is more commonly encountered 1-3 months after calving, often during oestrus when the cow mounts another cow.

CASE 1.93

1 What conditions would you consider (most likely first)? Include: radial nerve paralysis following trauma in the mid/distal humeral region; trauma of the shoulder/elbow joints; penetration wound causing cellulitis/joint infection; severe foot lesion (foot abscess, septic pedal arthritis).

2 What treatment(s) would you administer? Clinical examination failed to reveal any evidence of a fracture and there are no joint swellings. The injury occurred

2 weeks ago, therefore corticosteroid injection to reduce any associated soft tissue swelling would be unlikely to have much beneficial effect. The cow was isolated with her calf in a small paddock.

3 What is the prognosis for this cow? The cow showed signs of improvement after 3 months and was fully recovered after 6 months. Such protracted convalescence is normal for radial nerve damage.

CASE 1.94

1 Identify the potentially toxic plant present in the field? Senecio jacobaea (ragwort). This plant is uncommon in the UK but can occur in many countries worldwide, especially under extensive grazing conditions. Senecio spp. contain pyrrolizidine alkaloids. Poisoning usually occurs following ingestion of the wilted plant in conserved forage such as hay or silage.

2 What clinical signs might be expected? Clinical signs are caused by chronic liver damage and include chronic weight loss, diarrhoea, jaundice and peripheral oedema, with possible ascites caused by hypoproteinaemia. Affected cattle are often dull and even obtunded. There may be evidence of tenesmus with resultant rectal prolapse. The important differential diagnoses include chronic liver fluke infestation and lead poisoning.

3 How is the diagnosis confirmed? Diagnosis is based on clinical evidence of a hepatopathy with exposure to ragwort (check silage/hay). Elevated liver enzyme concentrations reflect the hepatic insult. Diagnosis is confirmed following liver biopsy or necropsy.

4 What treatment and control measures could be adopted? There is no effective treatment once clinical signs appear. Remove contaminated feed. Control ragwort on pasture by use of selective herbicides. Wilted ragwort is more palatable to cattle, therefore it must not be topped if cattle remain in the field. Ragwort is not a problem in mixed grazing system with sheep.

CASE 1.95

1 What conditions would you consider (most likely first)? Rickets, osteochondrosis dissecans.

Lack of mineralisation of a cereal-based ration along with vitamin D deficiency can lead to gradual osteomalacia of growing bones and spontaneous long bone fractures. Fractures involving the cervical vertebrae lead to recumbency, with evidence of cervical pain. This situation arises due to inadequate calcium supplementation with excess dietary phosphorus typically present in a cereal-based ration. Less severely affected calves show widening of the metaphyses, particularly of the proximal third metacarpal and third metatarsal bones, causing moderate lameness.

2 What further examinations could you undertake to confirm your diagnosis? Radiography reveals poor mineralisation and flaring of the distal metaphyses. In some cases there may be erosion of articular cartilage and exposure of subchondral bone (1.95b) with accompanying joint effusion and severe lameness. Diagnosis is based on a cluster of spontaneous long bone fractures and review of the diet, with detailed investigation of its mineral supplementation including vitamin expiry date.

3 What treatment would you administer? There is no specific treatment for the lame bulls in the group. Depending on the degree of lameness, these animals should be reared in isolation and slaughtered as early as possible on farm, as they are unlikely to be fit for transport to a slaughterhouse. Immediate correction of the mineral content of the ration with appropriate vitamin D supplementation is necessary.

Problems have occurred when farms have changed to organic rearing systems and it is essential to ensure that diets contain the correct vitamin and mineral supplementation.

CASE 1.96

1 What conditions would you consider (most likely first)? Include: ringworm (Trichophyton spp. infection); sarcoptic mange; lice (pediculosis); chorioptic mange.

2 What further tests could be undertaken? Microscopic examination of hair/ skin scrapings from the periphery of the lesions reveals fungal hyphae typical of Trichophyton spp. infection. Culture examination can be undertaken on special media.

3 What actions/treatments would you recommend? There are no specific treatments in many EU countries, although in-feed griseofulvin medication for 10-14 days is still available in some countries. Most farmers elect to do nothing, as lesions eventually regress over 3-6 months, but in the interim the cattle do not look well and there is the risk of transmission to other livestock. Unless buildings are thoroughly cleaned when depopulated, infection may remain and clinical signs appear in the next batch of cattle.

An attentuated ringworm vaccine strain of T. verrucosum is routinely used in many dairy herds but rarely in beef cattle.

4 Are there any special concerns? There is a zoonotic risk following contact with the calves or their environment.

CASE 1.97

1 Describe the abnormal findings in the sonogram. The walls of the right ventricle are clearly visible at 7 and 13 cm from the probe head. There is an increased amount of fluid (transudate) within the pleural space (anechoic areas). There are 5-6 almost spherical hypoechoic ‘nodules' present within the pleural space, several of which appear adherent to the pericardium; there are several ‘nodules' that are adherent to the parietal pleura. As the probe head is moved dorsally there is an increased depth of pleural effusion extending to 10 cm deep. Examination of the lungs fails to reveal any abnormality of the visceral pleura.

2 What is this lesion? The masses are consistent with a tumour. The absence of inflammatory exudate (fibrin within the anaechoic pleural fluid) would suggest that infection is unlikely. Furthermore, the ‘nodules' do not have the appearance of abscesses.

3 What is the likely cause? Enzootic bovine leucosis (EBL) must be considered a possible cause of a tumour in countries where this virus is endemic in the cattle population. The suspected tumour masses are outwith the pericardial sac, therefore a heart base tumour is unlikely.

4 What action should be taken? The cow should be culled for welfare reasons. Where appropriate, blood samples should be collected for EBL testing. In some countries regulatory authorities should be informed about the suspicion of a tumour in an adult bovine animal. Necropsy of this cow revealed the nature of the tumour mass (1.97b, arrow) with metastases to the mediastinal lymph nodes. EBL testing was negative; the nature of the tumour was not identified because of cost.

CASE 1.98

List five biosecurity measures and five biocontainment measures that will reduce the risk of Salmonella dublin infection in a dairy herd.

Biosecurity:

• Avoid introducing potentially infected animals by maintaining a closed herd. Quarantine all introduced stock for at least 4 weeks.

• Source new stock from other farms with high health status and not from markets.

• Avoid communal grazing.

• Maintain good fences to prevent straying of neighbouring stock.

• Insist visitors have clean boots and disinfect before entering and leaving the farm premises.

Biocontainment:

• Consider herd vaccination.

• Isolate sick animals in dedicated isolation boxes and not calving boxes.

• Clean and disinfect buildings between occupancies. Provide good drain­age and waste removal.

• Protect all feed stores from vermin

• Only spread slurry on arable land wherever possible. Leave all grazing land at least 3 weeks after spreading slurry.

CASE 1.99

1 What conditions would you consider (most likely first)? Septicaemic colibacillosis; enterotoxigenic Escherichia coli; peritonitis from ascending umbilical infection.

2 What is the cause of this problem? Two factors are critical in the development of septicaemic colibacillosis:

• Inadequate passive immunity from colostral immunoglobulins.

• Exposure and invasion via the nasal, oropharyngeal mucous membranes, tonsil, upper respiratory tract, or intestine of an E. coli serotype able to produce an overwhelming septicaemia, endotoxaemia and death. The umbilicus is not the major portal of entry for bacteria causing septicae­mia. A dirty calving environment with high bacterial challenge increases the risk of disease.

3 What treatment would you administer, and what is the prognosis? Florfenicol is a good antibiotic choice for septicaemic calves, but the prognosis is hopeless if the calf shows seizure activity and there is early evidence of polyarthritis

(slight fluid distension of several joints; see necropsy findings in 1.99b; note that joint infection and accumulation of exudate can be severe even at 3 days old). Supportive therapy includes IV NSAID injection. A high dose of soluble corticosteroid (1.0 mg/kg dexamethasone) reduces cerebral oedema but remains controversial in the treatment of bacterial meningoencephalitis, which is part of the septicaemic condition.

4 What control measures would you implement? Septicaemia is best prevented by ingestion of 7-10% of the calf's body weight of colostrum (3 litres minimum is recommended) within the first 6 hours of the calf's life. Stored colostrum can be used if there is insufficient dam supply, but note

the potential risk for paratuberculosis transmission. Hygiene in calving boxes should be improved as should calf accommodation. Numerous methods can be used to assess passive antibody transfer, but total plasma protein determination using a refractometer is the cheapest and can be readily undertaken in the practice laboratory. Pre-colostral values of 40-45 g/l (4.0-4.5 g/dl) rise to >55-65 g/l (5.5-6.5 g/dl) from 24 hours after appropriate colostrum ingestion.

CASE 1.100

1 What action would you take? A large volume, low extradural lidocaine block (3 mg/kg) is administered to paralyse the hind legs and allow pain-free examination of the distal left hind leg. The bull is then heavily sedated with IV xylazine. (Note: Sedation should be given after extradural injection of the standing animal because paresis and sedation take effect at much the same time with the animal quietly and safely assuming sternal recumbency.) Flunixin is then injected IV. Careful paring of both claws of the left hind foot fails to reveal any sole abnormality and there are no discarging sinuses at the coronary band nor widening of the interdigital space typical of septic pedal arthritis.

A dorsoplantar radiograph of the right fetlock region is shown (1.100b). There is considerable sidebone of the lateral claw but no evidence of infection of either distal interphalangeal joint.

Further examination of the fetlock region was suggestive of thickening of the joint capsule but this interpretation was limited by the surrounding subcutaneous oedema. There was no indication to amputate a digit and the severity and duration

of lameness therefore dictated that the bull be euthanased for welfare reasons. The provisional diagnosis of septic fetlock was confirmed at necropsy, which revealed the fetlock joint to be filled with a pannus (1.100c, arrow). Arthrocentesis would have failed to yield a sample; arthrotomy would have been unsuccessful and only further prolonged suffering. The cause of the septic fetlock joint was not determined.

CASE 1.101

1 Describe the abnormalities present. There is marked erosion of the articular surface of the third metacarpal bone.

2 What action would you take? The prognosis is hopeless and the calf must be euthanased for welfare reasons. The extent of joint pathology is clearly evident (1.101b). There is extensive pannus within the joint. Marked joint effusion is uncommon in septic arthritis in cattle in all but neonatal calves.

In the absence of significant radiographic changes (or indeed radiographic examination in most practice situations), the decision to euthanase this calf should be based on the chronicity of the severe lameness, which is refractory to antibiotic therapy. Antibiotic therapy, and possibly joint lavage, for septic arthritis is rarely successful in calves more than several weeks old. It can prove difficult to convince a farmer that an animal with a septic joint will not respond to a ‘stronger’ antibiotic, but the welfare of the animal is paramount.

3 Are there any specific control measures? The cause of the joint infection in this case was not determined but presumed to be haematogenous in origin. It is not uncommon to find a single septic joint in growing ruminants where there is no obvious primary lesion.

CASE 1.102

1 What conditions would you consider (most likely first)? Spastic paresis; dislocated hip. Dorsal patellar luxation is rare in cattle.

2 What options would you consider? Many calves are euthanased for welfare reasons following clinical examination because of the prohibitive cost of surgery and only 75% success rate in early cases; calves showing signs for several months, or affecting both hind legs, have a poor outcome.

Tenotomy of the gastrocnemius muscle is rarely undertaken because of frequent recurrence. Partial or total tibial neurectomy is performed under xylazine sedation and large volume extradural block (3 mg/kg lidocaine at the sacrocoggyceal space) with the affected leg uppermost for surgery. Blunt dissection between the two heads of the biceps femoris muscle in the lateral thigh reveals the tibial and peroneal nerves, which are isolated and stimulated with forceps (nerves shown in 1.102b in a prepared necropsy specimen). Stimulation of the tibial nerve causes flexion of the digits and fetlock; once identified, a 5 cm portion of nerve is sectioned and removed.

3 What control measures could be implemented? The cause is not known but a hereditary component is likely. The condition is more common in the Belgian Blue breed. There are no specific control measures in this particular herd with crossbred cattle and no Belgian Blue genetics.

CASE 1.103

1 What conditions would you consider (most likely first)? Squamous cell carcinoma of the hard palate or nasal cavity; ethmoid carcinoma; nasal lymphosarcoma; nasal osteosarcoma; osteomyelitis of the hard palate; advanced erosive fungal sinusitis.

2 What further tests could be undertaken? Mediolateral radiographs of the muzzle revealed a soft tissue opacity extending from the level of the first molar to the zygomatic arch and dorsal nasal conchae (1.103b). The opacity had ill-defined edges and protruded into the pharyngeal region and along sinus contours.

Rhinoscopy revealed the ventral and common meati of both nostrils to be filled with impacted ingesta, which prevented advancement of the rhinoscope beyond the level of the oral lesion.

3 What action would you take? There is suspicion of metastasis in the enlarged submandibular lymph

nodes, but squamous cell carcinoma does not usually spread beyond the local drainage lymph nodes. Immediate slaughter for human consumption is prevented by the farmer's antibiotic administration and the interval to salvage is considered too long, therefore the cow was euthanased for welfare reasons. Histopathology confirmed the diagnosis of squamous cell carcinoma.

CASE 1.104

1 What conditions would you consider (most likely first)? Osteoarthritis of the stifle caused by repeated trauma with variable rupture of the cruciate ligaments; osteoarthritis of the hip.

Repeated joint trauma (possibly caused by bulling injuries) results in joint instability with proliferation of fibrous tissue within the joint capsule, degeneration and loss of articular cartilage, exposure and eburnation of subchondral bone, and peripheral osteophyte formation (1.104b, arrows). Crepitus is difficult to appreciate because it can be difficult to distinguish from ‘clunking’ of the normal hip joint. Few cows are so neglected that there is subchondral bone grating against subchondral bone to produce crepitus. Many beef bulls can reach 1.0-1.1 tonnes compared with cow liveweights of 600-700 kg (1,320-1,540 lb).

2 What other tests could you employ? Detailed radiographic and ultrasonographic examinations are rarely employed because after several months’ moderate lameness and severe muscle wastage the cow must be culled for welfare reasons irrespective of further findings.

3 What treatment would you administer? Analgesics may afford temporary reduction in lameness for 3-5 days, but affected cattle should be culled because of chronic pain and they will also not be productive. It can prove difficult to be certain that such cattle are fit to transport to a slaughterhouse; the nearest plant must always be used.

4 What action would you take? There are no specific control measures. Extreme beef bulls should be avoided and their condition limited to fit not obese, as commonly purchased at breeding sales. Review underfoot conditions that could lead to slips and falls if cattle are bred indoors. Cull early to avoid chronic pain (see 1.104b).

CASE 1.105

1 Describe the abnormalities present. There are no appreciable abnormalities visible on the radiograph.

2 What action would you take? The calf is heavily sedated with xylazine (stage 4; 0.3 mg/kg IM). The calf is left undisturbed and after 10 minutes it is found in sternal recumbency. Flunixin is injected IV. A low extradural block of lidocaine (3 mg/kg) is administered to paralyse the hind legs and allow pain-free

examination of the fetlock joint. A 14 gauge needle is inserted into the fetlock joint at two sites and the joint flushed with Hartmann’s solution, but no foreign material is displaced. The joint is then prepped for an arthrotomy because the material in the joint is thought to be a pannus (fibrin firmly adherent to the joint surface, bacteria and inflammatory cells), which cannot be flushed through needles. The arthrotomy yields large plaques of pannus. The prognosis is hopeless and the calf is euthanased for welfare reasons. The extent of joint pathology is clearly evident (1.105b) and it proves impossible to remove all the pannus even via an arthrotomy. 3 Are there any specific control measures? The farmer had suspected a cellulitis lesion and treated the calf himself. It is debatable whether joint lavage/arthrotomy would have been successful at the first signs of lameness. Joint lavage is most useful in neonatal calves rather than in growing calves/adult cattle. Radiography is of little clinical help during the early stages of joint sepsis and may mislead the clinician into thinking that there is no significant joint pathology present. In some cases there is widening of the articular space, but the contralateral normal joint should be radiographed for comparison; even then, angulation of the beam can affect this measurement. Arthrocentesis is often negative as the joint contains a pannus rather than more fluid exudate.

CASE 1.106

1 What is the likely cause? Localised infection/cellulitis caused by non-sterile subcutaneous injection following treatment with calcium borogluonate or dextrose injection; subcutaneous abscess; haematoma.

2 What action would you take? No action is necessary at the moment. There is no evidence that the swelling is developing into a large abscess and about to discharge. Ultrasound examination would identify whether the swelling is a haematoma or abscess; it may prove difficult to differentiate subcutaneous accumulation of fluid that has not been absorbed from cellulitis.

3 How can this problem be prevented? Use a sterilised flutter valve and new hypodermic needle for all subcutaneous injections. Too often, the farmer’s flutter valve is rinsed through with hot water and left hung up in the milk bulk tank room with the needle still attached until used again. The value of subcutaneous injection of calcium borogluconate is probably overrated because it is often poorly absorbed and is irritant and painful. The extent of subcutaneous reaction is evident at necropsy of any recently calved cow treated by this route. Calcium chloride gels are more effective as supportive treatment for milk fever, but care is needed in cattle without a proper swallow reflex. On a herd basis, high milk fever prevalence is greatly reduced by feeding a diet with a high dietary cation/anion balance in consultation with the farm’s nutritionist.

CASE 1.107

1 What conditions would you consider (most likely first)? Include: summer mastitis; bacterial endocarditis; polyarthritis; other chronic bacterial infections; redwater (babesiosis).

2 What is the cause? Primary invasion of the mammary gland, with either the anaerobic organism Peptococcus indolicus or Streptococcus dysgalactiae, is followed by Trueperella pyogenes infection to cause summer mastitis. There is circumstantial evidence only to link the sheep headfly Hydrotaea irritans with disease transmission.

3 What treatments would you administer? The right forequarter will not recover normal lactogenesis. Intramammary antibiotic infusion is ineffective due to the chronicity/extent of the infection, although parenteral antibiotics, typically penicillin, are administered. Frequent stripping of the affected quarter every 2-4 hours is necessary to remove toxins and cellular debris, but is not a simple procedure because of the painful oedematous teat. Lancing the teat in the vertical plane, thereby reducing the risk of haemorrhage associated with teat amputation, to facilitate drainage often produces disappointing results. NSAIDs, such as flunixin meglumine or ketoprofen, provide pain relief and stimulate appetite. Corticosteroids reduce joint effusions and reduce inflammation, although they will cause abortion if administered to cattle later

than the first trimester of pregnancy, although this is not a concern in this non-pregnant cow.

4 What control measures would you recommend? Dry cow therapy/teat sealants (1.107b; operator should be wearing gloves) remain the most effective means of preventing summer mastitis. Fly repellants, whether in the form of pour-on, spray-on or impregnated ear tag, provide useful protection against nuisance flies.

CASE 1.108

1 What conditions would you consider (most likely first)? Infection of the proximal interphalangeal (P1/P2) joint; septic pedal arthritis; penetration wound and associated cellulitis.

2 What action would you take? Amputate the digit through distal P1 under IVRA after first injecting flunixin IV. Use lidocaine as procaine is not licensed for IV use, observing meat withholding times as appropriate. It can prove difficult to judge the incision site through proximal P1 - aim to exit 2 cm proximal to the discharging sinus on the lateral aspect with your Gigli wire. The bull was not sound until 3 weeks after amputation, which is a longer convalescence period than usual. Putting a block on the sound claw and lavaging the infected joint could have been attempted, but this would have cost the same as digit amputation and likely not have achieved such a good outcome.

Farmers are reluctant to pay for radiography because clinical judgement is almost always correct in these cases. However, radiography provided some interesting findings (1.108b). There is loss of the articular surfaces of the proximal interphalangeal joint, consistent with chronic infection, and a large defect of the articular surface of P1, possibly arising from infection of the associated growth plate.

CASE 1.109

1 What is your diagnosis? Superfoul with extension of infection into both distal interphalangeal joints. Interdigital necrobacillosis with extension into both distal interphalangeal joints

Superfoul is the term often used to describe the peracute form of interdigital necrobacillosis (‘foul of the foot').

2 How could you confirm your diagnosis?

Radiography demonstrates extension of infection into both distal interphalangeal joints (1.109c). The extensive bone destruction suggests that the lesions are of more than

3 weeks' duration.

3 What action would you take? Immediate action for superfoul is essential. Under IVRA, debride the interdigital lesion and pack with 2-4 500 mg clindamycin tablets. Apply a bandage. Treat cow with tylosin (10 mg/kg IM q12h for at least 5 days). Administer a NSAID such as

flunixin or ketoprofen for 3-5 days. Isolate the cow in a well-bedded straw pen. However, these measures are far too late for this cow and she must be euthanased immediately for welfare reasons.

Review the management of this cow and investigate whether other cattle are affected. Inspect the cattle accommodation paying particular attention to hygiene and slurry management. Advise veterinary examination of lame cows as soon as possible, especially where there is no response to antibiotic therapy of suspect ‘foul of the foot’ cases.

4 List any management, prevention and control measures. Quarantine all cattle introduced into the herd. Biosecurity is also very important for many other diseases. Reduce environmental contamination and increase bedding in cubicles. Disinfectant footbaths containing either formalin or copper sulphate are reported to provide good control. Attend to all lame cows immediately.

CASE 1.110

1 What action would you take? It can prove difficult to decide whether to continue with antibiotics for another day or so or to flush the joint. Previous success with early joint lavage on this farm made the farmer keen not to delay. Flunixin is

injected IV. The calf is sedated with IM xylazine. The calf is left undisturbed and after 10 minutes is positioned in sternal recumbency and a high extradural block of lidocaine (3 mg/kg) is administered to paralyse the hind legs and allow pain- free examination and lavage of the stifle joint. A 14 gauge needle is inserted into the stifle joint and a slightly turbid free- flowing (non-viscous) sample is obtained. Another needle is inserted on the other side of the joint and the joint alternately flushed through these needles with 3 litres of Hartmann’s solution (1.110). This calf made a very good recovery and was much less lame 2 days later.

In some joint infections, large plaques of fibrin/pannus form within days of

lameness being detected. The prognosis is hopeless in such cases because the material cannot be flushed out.

2 Are there any specific control measures? Bacteraemia with localisation within joint(s) follows management shortcomings related to failure of passive transfer and poor environmental hygiene, allowing high bacterial challenge. Bacteraemia/ septicaemia in neonatal calves is one of the few infections where a fluoroquinolone antibiotic could be considered; clinical experience shows that marbofloxacin may provide a better treatment response than florfenicol, but there are no supporting published data.

CASE 1.111

1 What conditions would you consider? Osteoarthritis of the tibiotarsal joint as a consequence of wear and tear. Some degree of joint effusion of the tibiotarsal and tarsometatarsal joints is very common in many beef bulls and proves difficult to interpret because these bulls often appear sound.

2 What assessment could you undertake? Radiography of the tarsus (1.111b, c) shows marked osteophytosis of the tarsometatarsal joint in particular. The extensive osteophytosis appears to contradict the history of low-grade intermittent lameness, but the tarsometatarsal joint is a low motion joint where ankylosis may not cause marked lameness.

3 Is this bull fit for future breeding? Predicting future breeding of this bull is difficult based on a single examination. Repeat radiographs should be taken in 6-12 weeks to check progression of lesions, particularly those involving the more important tibiotarsal joint. In a commercial farming situation, the bull is in excellent condition and is now 6 years old; the pragmatic option may be to sell the bull for slaughter, thus generating approximately 50% of the cost of an 18-month-old replacement. An extended calving period and high barren rate as a consequence of reduced bull fertility has a major affect on beef herd profitability; farmers will often comment that their first loss is the best loss!

4 How could this problem be reduced/prevented? The osteophytosis probably resulted from joint trauma during mating and there are no obvious control measures other than appropriate underfoot conditions.

CASE 1.112

1 Comment on the significant radiographic abnormalities. There is marked soft tissue swelling over the abaxial aspect of the coronary band. There is marked widening of the articular space of the distal interphalangeal joint with extensive erosion of articular cartilage. There is extensive osteophytosis involving the distal interphalangeal joint and, to a lesser extent, the proximal interphalangeal joint. These radiographic findings are consistent with chronic infection of the distal interphalangeal joint of at least 3 months' duration and probably longer.

2 What treatment would you administer? The extensive osteophytosis will probably result in ankylosis in several weeks/months. As the cow is moderately lame, a block is fitted to the sole of the sound claw of the right hind foot and she is treated for 3 consecutive days with a NSAID. The cow was 3-4/10 lame after this treatment course. The cow continued to improve and was sound when transported for slaughter 2 months later. An alternative approach would have been to amputate the digit through distal P1, but this would have caused short-term acute pain whereas the joint was almost ankylosed and a block further reduced lameness.

3 How should this problem have been treated when the cow first presented lame? The cow should have been presented for veterinary examination soon after it failed to respond to the treatment administered by the farmer; however, several weeks/ months often elapse before such examination occurs (this case). Radiographic examination greatly assisted the prognosis and management of this case and need not be expensive because only one dorsoplantar view is needed.

CASE 1.113

1 What conditions would you consider (most likely first)? Tetanus; hypomagnesaemia; lead poisoning; meningitis. The calf is too young for polioencephalomalacia.

2 What laboratory tests could be undertaken to confirm your provisional diagnosis? There is no confirmatory test for tetanus and diagnosis is based on

the clinical signs and history. The elastrator ring used for castration, applied illegally to the scrotum at 6 weeks old, could be the origin of the problem (1.113b).

3 What treatment would you administer? There is no consensus regarding the dose rate of antitoxin; one protocol gives 50 units/kg liveweight IV followed by IM doses of the same amount as thought necessary every 12 hours. Crystalline

penicillin is recommended IV at the first examination for its more rapid onset of action, followed by 44,000 units per kg of procaine penicillin IM twice daily. NSAIDs should be given daily to provide analgesia. Acetylpromazine (0.05 mg/ kg q8h) should be administered to provide muscle relaxation. Local wound debridement remains controversial. Tetanus cases should be housed singly in a darkened, deep-bedded shed. None of these treatments would have produced any improvement in this case and the calf was euthanased for welfare reasons.

4 What control measures would you recommend? Efficacious vaccines are available but are not routinely used unless there is a farm history of clostridial disease (more commonly blackleg).

CASE 1.114

1 What is this defect? Horizontal fissure in the hoof horn (‘thimbling’).

2 What is the likely cause? Poor horn production during a severe toxaemic episode such as coliform mastitis or metritis appears as a horizontal fissure in the hoof horn of all eight digits. As this defect in the wall grows down to about two-thirds of its length 3-4 months later, it weakens and further separates from the healthy horn proximally. The corium remains intact distal to the horizontal fracture, holding the distal hoof horn attached at the toe. This fissure moves when weight is taken, tensing the corium still attached distally and causing variable pain and lameness. Foreign material can occasionally become impacted in the fissure, causing pressure, and may lead to abscesses.

3 What action would you take? Careful hoof paring is only necessary when the cow is lame in order to remove all underrun horn and impacted material. This is best achieved with hoof shears, taking note that the hoof capsule may still be attached at the toe.

4 Are there any specific control measures? There are no specific control measures except for prompt treatment of toxic conditions.

CASE 1.115

1 Describe the abnormalities present. There is extensive loss of the articular surface of the glenoid of the scapula. The articular space is greatly increased.

2 What is the likely cause? The radiographic changes are consistent with chronic septic arthritis of the right shoulder joint.

3 What action would you take? The calf should be euthanased for welfare reasons because the bony changes are now too extensive for joint lavage/arthroscopy. After several days, joint infection causes formation of a pannus, which is firmly adherent to articular cartilage and proves very difficult to remove even by arthroscopic surgery. A pannus is a membrane of granulation tissue (fibroblasts and neovascularisation) and bone marrow-derived cells (macrophages). Differentiation of fibrin deposition within a joint and a pannus proves very difficult on gross examination because a

pannus is an extension of the pathological change within the joint. However, a pannus is more adherent to the synovial membrane and articular cartilage than fibrin, and is much more difficult to peel off. An example of pannus in a case of a septic stifle joint is shown (1.115b); the widespread and adherent nature of the pannus prevents successful treatment even by arthroscopy/arthrotomy. There are few radiographic

changes during the early stages of the infectious disease process except for slight widening of the articular space, which is best appreciated by comparing it with the contralateral normal joint, although projection of the beam can cause artefacts with respect to distance between articular surfaces. Arthrocentesis often fails to yield sufficient sample for analysis and must not be mistaken for the absence of pathological changes within the joint.

4 Are there any specific control

measures? There was no evidence of

a puncture wound over the shoulder joint and infection was assumed to have been haematogenous during the neonatal period. Review colostrum management and environmental hygiene.

CASE 1.116

1 What conditions would you consider (most likely first)? Include: thymic lymhosarcoma causing compression of the cranial vena cava and oesophagus; right­sided heart failure caused by severe interstitial pneumonia or a space-occupying mass in the thorax such as a large mediastinal abscess; dilated cardiomyopathy; septic pericarditis; chronic suppurative pneumonia/pleuritis/pleural effusion; endocarditis.

Mild bloat results from compression of the oesophagus as it passes through the mediastinum by the tumour mass.

2 How could you confirm your diagnosis? There is no confirmatory diagnostic test for thymic lymhosarcoma; however, several of the important differential diagnoses can be eliminated by transthoracic ultrasonography of the lungs, pleurae and heart; no abnormalities were found in this case. The mediastinum is separated from the chest wall by aerated lung and cannot be examined ultrasonographically.

3 What action should you take? In the UK, concerns over enzootic bovine leucosis virus (EBLV) require notificationofregulatoryauthorities. The heifer was euthanased for welfare reasons and the diagnosis of thymic lymphosarcoma confirmed at necropsy (1.116b). Tests for EBLV proved negative.

CASE 1.117

1 Interpret the radiographic findings (1.117a, b). Fracture through the proximal tibia involving the epiphysis.

2 What is the prognosis? Repair of the fracture is not possible and the calf was euthanased for welfare reasons.

3 How could this situation have been prevented? Excessive force using a calving jack to deliver large beef calves is not uncommon. Fractures may result when calving ropes are attached to a jack and the cow falls down, caused by the pressure exerted and the acute pain produced. Femoral nerve paralysis affecting the calf is common following ‘hip-lock’. Wherever possible, after the calving problem has been assessed and the calving ropes applied, the cow should be haltered, released from the cattle stocks and allowed to assume lateral recumbency before pulling the calf. Unfortunately, this recommendation is not always possible because of insufficient farm staff, poor facilities and an uncooperative and aggressive cow. If, as a veterinary surgeon, you attempt to deliver the calf with the dam restrained in cattle stocks, always forewarn the farmer of the risks involved, otherwise you may be found liable for any adverse outcome if the cow falls down.

CASE 1.118

1 What are the possible causes (most likely first)? Sciatic nerve damage; tibial nerve damage; peroneal nerve damage.

The sciatic nerve supplies the extensor muscles of the hip and hock and the flexors of the stifle and fetlock (tibial branch), and the extensors of the fetlock (peroneal branch). Damage to the sciatic nerve proximal to the stifle (before branching) causes the hip, stifle and hock to drop and the fetlock joint is knuckled, but the leg can still take weight. Sciatic nerve injury may result from calving injury and pelvic trauma, and perineural injection.

Tibial nerve injury results in flexion of the hock and slight knuckling of the fetlock joint, but not as severe as peroneal nerve paraylsis, where the dorsal surface of the hoof may contact the ground. Peroneal nerve injury over the lateral aspect of the stifle region typically occurs following prolonged recumbency on an unyielding surface.

2 What treatment would you administer? A single injection of dexamethasone may be beneficial if the injury has just occurred (e.g. during calving), although such treatment is difficult to evaluate. Tibial and peroneal nerve damage resolves over several weeks without treatment provided the cow is ambulatory.

3 How could this problem have been avoided? Farmers must not use excessive traction during delivery of the calf. Provide deep straw bedding in calving accommodation to prevent pressure over bony prominences. Regularly turn recumbent cattle from one side to the other side. Use an aseptic technique for injection of antibiotics and other preparations.

CASE 1.119

1 Describe the important radiographic findings. There is considerable lysis of P3 and osteophytosis of the distal interphalangeal joint.

2 What is this defect, and what is the likely cause? The findings are consistent with a diagnosis of toe necrosis. The aetiology has not been determined, but spirochaetes responsible for digital dermatitis have been implicated.

3 What action would you take? The conservative approach would be to apply

a wooden block (or equivalent) to the sound claw and pare away all underrun horn surrounding the toe necrosis lesion under IVRA, but this would create a considerable hoof defect, which is unlikely to heal. This approach would not address the osteoarthritis of the distal interphalangeal joint, as evidenced by the associated osteophytosis.

Digit amputation was undertaken under IVRA and IV injection of a NSAID. The extent of P3 lysis is shown in sagittal section (1.119b).

4 Are there any specific control measures? Measures should first be directed at the control of digital dermatitis; greatly improved slurry management, daily foot bathing and topical antibiotic (oxytetracycline) treatment of lesions. Be aware that spirochaete infection can be transmitted between cows by hoof knives and other equipment.

CASE 1.120

1 What conditions would you consider (most likely first)? Accidental toggling of small intestine or other viscus (not the abomasum); leakage of digesta from the toggling site and the development of diffuse peritonitis.

2 What laboratory tests could be undertaken to confirm your provisional diagnosis? Diagnosis is based on clinical signs and demonstration of an inflammatory exudate with a high protein concentration and an increased white cell count, with predominance of leucocytes, following ultrasound-guided abdominocentesis. Prior ultrasound examination is very helpful because peritonitis is not a simple diagnosis when infection has often been contained by the omentum (less likely in this case because toggling occurred just beneath the abdominal wall).

3 What treatment would you administer? Parenteral antibiotic therapy is hopeless in all but very localised cases of peritonitis, and is often undertaken in those situations where there has been limited investigation with the expectation that the animal is suffering from another infectious disease.

4 What is the prognosis? A guarded prognosis was afforded this cow; however, 3 litres of hypertonic saline was infused IV over 5 minutes followed by 30 litres of isotonic saline over the next 3 hours. Flunixin was also administered IV and florfenicol injected IM. The cow deteriorated further overnight and was euthanased for welfare reasons. Postmortem examination revealed extensive fibrinous adhesions in the cranioventral abdomen, with one toggle having torn through the wall of the small intestine.

5 What alternative surgical approach could have been undertaken? A right omentopexy undertaken in the standing unsedated cow under paravertebral anaesthesia is the more commonly adopted approach for LDA; this procedure takes longer and costs more, but results are generally better unless the surgeon is highly experienced with the toggling approach.

CASE 1.121

1 Describe the sonogram. There is a large accumulation of inflammatory exudate extending to more than 8 cm deep, with considerable fibrin deposition on the

serosal surface of the reticulum and bridging the space between peritoneum and reticulum. A similar image would have been obtained using a 5 MHz linear scanner (‘rectal scanner’).

2 What is the prognosis for surgery? The prognosis for recovery following surgery is guarded because the fibrin deposited on the serosal surface of the reticulum and fibrinous adhesions will markedly restrict reticular contractions even if a foreign body is successfully removed.

3 What action would you take? The cow should be euthanased for welfare reasons. The extensive peritonitis prevents on-farm slaughter for human consumption. This decision is proven correct by the necropsy finding (1.121b); note that the cow has been positioned in dorsal recumbency for postmortem examination and that the peritoneal fluid has drained, leaving only fibrin. The severity of lesions identified ultrasonographically often appears to be greater at postmortem examination.

4 What control measures could be employed? Examine farm records for history of cows culled due to unexplained poor performance (possible traumatic reticulitis and/or peritonitis cases) and any record of septic pericarditis to gauge the extent of potential problems. Check to see whether car tyres are used on silage clamps and the risk from these when fragments of decaying tyres are accidentally put into the total mixed ration wagon. Bonfire sites are another source of nails and other sharp debris. Discuss the possibility of prophylactic reticular magnets.

CASE 1.122

1 What is the likely cause? Large subcutaneous abscess; haematoma; umbilical hernia.

Ultrasound examination of the mass reveals a 15 cm diameter well- encapsulated anechoic area with multiple hyperechoic dots (1.122b) typical of an abscess.

2 What action would you take? To achieve drainage, lance the abscess

at its ventral margin where the capsule is at its thinnest. Expect some bleeding

from vessels in the abscess capsule wall but this will stop within 5-10 minutes.

The abscess cavity should be irrigated with very dilute povidone-iodine and repeated 2-3 days later. The incision should be packed with gauze swabs to prevent it healing. Parenteral antibiotic therapy is not necessary. While lancing the abscess is simple in a calf, a mature bull presents several risks from kicking and the bull should be confined in cattle stocks and sedated for safety reasons. While xylazine is licensed for IV use in cattle, romifine (1 mg/100 kg, off-label use) is a much better sedative.

CASE 1.123

1 What conditions would you consider (most likely first)? Include: peripheral vestibular lesion (otitis media); trauma to involve the peripheral facial nerve; listeriosis.

2 What is the likely cause? The vestibular system helps the animal maintain orientation in its environment, and the position of the eyes, trunk and legs with respect to movements and positioning of the head. Unilateral peripheral vestibular lesions are commonly associated with otitis media and ascending bacterial infection of the eustachian tube. There may be evidence of otitis externa and a purulent aural discharge in some cases, but rupture of the tympanic membrane is not a common route of infection.

3 What treatment would you administer? Pasteurella spp., Streptococcus spp. and Trueperella pyogenes have been isolated from infected lesions. A good treatment response is achieved with 5 consecutive days treatment with procaine penicillin, although other antibiotics including oxytetracycline and trimethoprim­sulphonamide combination are also used. Mycoplasma bovis is reported to be a common cause of otitis media in calves in endemically infected dairy herds. In this situation, a different antibiotic may be necessary such as a macrolide (e.g. tilmicosin, gamithromycin).

4 What is the prognosis for this case? The prognosis is very good in acute cases. The prognosis is poor in neglected cases where infection has extended into bone (empyema), but this is rare.

CASE 1.124

1 How would you correct this problem? The uterus is replaced after sacrococcygeal extradural injection of 5 ml of 2% lidocaine. Ideally, the cow should be haltered, cast and rolled onto her sternum and the hind legs positioned behind with the hips fully extended and the weight of the cow's hindquarters taken on her stifle joints, but this is not possible if there is only you and the farmer present and the cow is aggressive to humans. Instead, the cow is restrained in cattle stocks. The prolapsed uterus is cleaned in warm dilute povidone-iodine solution and any gross contamination

removed. The uterus is then held at the level of the vulva and replaced starting at the cervical end (1.124b). At first there seems to be little progress but eventually the uterine horn is replaced into the vagina and carefully returned to its normal ‘comma-shaped’ position. A

400 ml ‘calcium’ bottle (or similar) can be used to extend your reach to ensure the uterine tip is fully everted. A Buhner suture of 5 mm umbilical tape is placed subcutaneously surrounding the vulva to prevent repeat prolapse.

Very occasionally, the uterus can be inverted and would prolapse again, but it is held in place by the Buhner suture. This situation causes the cow to strain and should not be confused with the cow trying to pass the fetal membranes. Untie the Buhner suture, replace the uterus, which is often easier the second time because there is more tone in the uterine wall, and tighten the suture. The suture can be removed after 3-5 days.

2 What treatments will you administer? Oxytocin (40 iu IM). The cow is treated with parenteral oxytetracycline for 3 consecutive days to prevent metritis. There is no evidence of concurrent hypocalcaemia. The cow should be checked around 21 days after calving and treated with prostaglandin F2 alpha if there is evidence of chronic endometritis.

CASE 1.125

1 Describe the important sonographic findings. There are 5-8 very thin-walled fluid-filled structures (anechoic areas bordered by find circular white lines). There is no evidence of fibrin tags within the fluid. There is no testicular tissue or gut (small intestine) wall.

2 What conditions would you consider (most likely first)? The sonogram is consistent with a collection of very distended blood vessels forming a varicocoele. The cause of the varicocoele could not be determined but could have arisen following trauma after late Burdizzo castration, although this could not be proven. No evidence of surgical castration is noted but such scars are difficult to appreciate. There is no evidence of intestine walls, therefore a diagnosis of an inguinal hernia can be discarded. There are no visible testicles, therefore epididymitis and orchitis can be excluded.

3 What further investigations would you undertake? No further examination is necessary. You are convinced that there is no testicular tissue present in the scrotum and sign a certificate to this effect. Needle aspiration of the scrotum is contraindicated. Unfortunately, no information was available from the slaughter plant; more importantly the farmer received no complaint about this steer being a bull!

CASE 1.126

1 What conditions would you consider (most likely first)? Vitamin A deficiency; lead poisoning; polioencephalomalacia/sulphur toxicity for bore hole water supply; hepatopathy.

There is no obvious source of lead; the water is from a mains supply. The lack of a papillary light reflex would rule out polioencephalomalacia. There is no access to hepatotoxic agents/plants such as ragwort.

2 What further examinations could you undertake to confirm your diagnosis? Serum vitamin A analysis reveals concentrations consistent with deficiency.

3 What treatment would you administer? There is no effective treatment for the bulls in this group. Examination of the current supplement reveals that the minerals and vitamins are 6 months past their expiry date and included at only half the recommended rate. Immediate correction of the mineral and vitamin content of the ration is necessary for younger calves, although blindness may still result due to compression of the optic nerves as the animals grow, but the optic foramina remain the same size.

Careful loading of the blind animals and sympathetic management at the slaughter plant are essential. The affected cattle could be moved with normal cattle to guide their way. On-farm slaughter would be preferable if possible.

4 What other problems might be expected? Lack of mineralization of the cereal­based ration and vitamin D deficiency can lead to osteomalacia of growing bones and spontaneous long bone fractures. Less severely affected calves show widening of the metaphyses, particularly of the third metacarpal and third metatarsal bones, causing moderate lameness.