Hedgehogs

African pygmy hedgehogs, or four-toed hedgehog Atelerix albiventris (APH), have become popular pets over the past decade or so and are more frequently presented to the clinician.

Consultation and handling

Most hedgehogs can be handled reasonably easily, although this can vary between individu­als.

Anting, or anointing, is a behavior seen when the hedgehog tastes or mouths a novel food or substance. Excessive salivation is triggered that, when it has been mouthed into a thick substance, is then spread along the hedgehog's sides and back. Many reasons have been sug­gested for this, including antipredation, but its true function remains unclear.

Hedgehogs can be asymptomatic carriers of ringworm, so caution should always be exer­cised when handling them. Wearing gloves will help protect from ringworm plus reduce the risk of an urticarial reaction from the pinpoint pressure from particularly prickly hedgehogs can produce on the palms of your hands.

African pygmy hedgehogs should kept at an environmental temperature of 24° to 30° C; at temperatures below 18° C or above 30° C they may enter torpor. For European hedgehogs true hibernation is triggered by temperatures falling consistently below 15° to 17° C, and arousal is triggered by temperatures rising above 12° C.

Blood sampling

Under general anesthesia, use the jugular vein for larger volumes. Small amounts can be taken from the cephalic, lateral saphenous, and femoral veins. The vena cava can be accessed, but the heart lies further rostral in hedgehogs so care should be taken when using this method.

Nursing care

Thermoregulation

For general principles see “Thermoregulation” under Nursing Care in Chapter 2. Keep African pygmy hedgehogs at 24° to 30° C; avoid temperatures below 18° C as this may induce torpor even in healthy hedgehogs.

Fluid therapy

Fluids can be given subcutaneously up to 100 mL/kg beneath the loose skin over the dorsum, although absorption may take some time. Vascular access is difficult. The cephalic vein may be accessible for bolus fluids; otherwise consider intraosseus administration into the trochan­teric fossa or proximal tibia.

Nutritional support

Hedgehogs need to be fed a high-quality diet. Normal diet should be a mixture of high- quality dried cat foods, live invertebrate prey such as mealworms, and some vegetable mate­rial. Do not give milk as this can trigger diarrhea. Anorexic hedgehogs can be offered or fed on commercially available supportive powdered carnivore or omnivore diets or on high- calorie wet foods as available for cats.

Analgesia

Anesthesia

Starve for 4 hours maximum to reduce risk of regurgitation.

Gaseous anesthesia

• Premedicate with atropine at 0.01 to 0.05 mg/kg SC to prevent hypersalivation.

• Induction with gaseous isoflurane in an induction chamber

• Maintain either with a mask or intubate with small-diameter endotracheal tube ((mycosis fungoides—Chung et al 2014)

Alopecia and quill loss

• Dermatophytosis (ringworm)—Trichophyton mentagrophytes var. erinacei, Arthroderma benhamiae var. erinacei, Microsporum spp.

• Mites

• Bacterial dermatitis

• Staphylococcus simulans (Han et al 2011)

• Epitheliotropic T-cell lymphoma (mycosis fungoides—Chung et al 2014)

• Ectoparasites

Scaling and crusting

• Ringworm—Trichophyton mentagrophytes var. erinacei, Arthroderma benhamiae var. erinacei, Microsporum spp.

• Epitheliotropic T-cell lymphoma (mycosis fungoides—Chung et al 2014)

• Ectoparasites

Erosions and ulceration

• Bite wounds

• Burst abscesses

• Foot and mouth disease

Nodules and nonhealing wounds

• Papillomas (suspected viral etiology)

• Pododermatitis

• Abscesses

Changes in pigmentation

• Dermatophytosis

• Mites

• Neoplasia

Ectoparasites

• Mites

• Caparinia erinacei, C.

• Notoedres oudesmani

• Notoedres cati (Pantchev and Hofmann 2006)

• Chorioptes spp.

• Otodectes cyanotis (ear mites)

• Demodex erinacei

• Sarcoptes spp.

• Neotrombicula spp. (chiggers)

• Ticks

• Rhipicephalus sanguineus (APH)

• Haemaphysalis erinacei (APH)

• Ixodes ricinus (EH)

• Ixodes hexagonus (EH)

• Fleas

• Archeopsylla erinacei

• Myiasis

• Lucilia spp.

• Calliphora spp.

Neoplasia

• Mast cell tumor

• Mammary tumors

• Squamous cell carcinoma

• Sebaceous carcinoma (Kim et al 2010)

• Neurofibroma

• Extraskeletal osteosarcoma (Phair et al 2011)

• Epithelioid variant of hemangiosarcoma (Finkelstein et al 2008)

• Epitheliotropic T-cell lymphoma (Chung et al 2014; Spugnini et al 2008)

Otitis externa

Pinnal dermatitis

Cutaneous emphysema

Other findings on clinical examination

• Discharge from ear canal; unpleasant smell from ear (otits externa)

• Crusty areas on pinnae, especially around margins (pinnal dermatitis)

• Quill loss, hyperkeratosis (dermatophytosis, bacterial dermatitis—Fig. 6-1)

• Quill loss, chronic pruritic dermatitis leading to self-trauma, scabs, lethargy, dehydration, and weight loss (Caparinia mites)

• Vesicles or open lesions on feet, muzzle, perineum, and tongue (foot and mouth disease)

Fig. 6-1. Hedgehog exhibiting quill loss secondary to a bacterial dermatitis.

Investigations

1. Microscopy: Examine fur pluck, acetate strips, or skin scrapes to affected area and examine for ectoparasites and ringworm.

2. Cytology: Stain with lactophenol blue for ringworm.

3. Examine material from ear canals for Otodectes cynotis.

4. Bacteriology and mycology: Hair/quill pluck or swab lesions for routine culture and sensitivity.

5. Fine-needle aspirate followed by staining with rapid Romanowsky stains

6. Biopsy obvious lesions.

7. Ultraviolet (Wood's) lamp: Positive for Microsporium canis only (not all strains fluoresce)

8. Radiography

9. Routine hematology and biochemistry

10. Endoscopy

11. Biopsy

12. Ultrasonography

TreatmentZspecific therapy

• Bite wounds

• Clean and debride; hedgehogs may self-mutilate, so primary closure with subcuticular suture pattern is preferred.

• Abscesses

• Drain and debride; some may require surgical removal.

• Be aware of possibility of mycobacteriosis.

• Bacterial dermatitis

• Appropriate antibiosis

• Clean lesions with topical antibacterial preparations (e.g., chlorhexidine/F10).

• Papillomas

• Likely benign; surgical resection if required

• Dermatophytosis (ringworm)

• Systemic antifungals

- Itraconazole at 5 to 10 mg/kg PO every 12 to 24 hours

- Ketoconazole 10 mg/kg PO b.i.d.

- Griseofulvin 25 to 50 mg/kg PO daily

• Potential zoonosis

• Mites

• Caparinia infestations are often highly pruritic and may require antiinflammatories to control pruritis and covering antibiosis for secondary skin infections.

• Ivermectin 0.2 to 0.5 mg/kg SC every 2 weeks for 3 treatments

• Selamectin topically at 15 mg/kg, 2 doses at 30-day interval (Delk et al 2013)

• Topical 10% imidacloprid plus 1.0% moxidectin spot-on (Advocate for Cats (UK), Advantage Multi (US), Bayer) at 0.1 mL/kg (Kim et al 2012)

• Moxidectin 0.3 mg/kg SC; repeat after 10 days (Pantchev and Hofmann 2006)

• Permethrin 1%, apply once only

• Amitraz 0.3% dip every 7 to 10 days

• Fleas

• As for mites; also environmental control as for other small animal species

• Ear mites

• Topical antiparasitic ear preparations, although the small size of the ear canal may prevent effective treatment.

• Selamectin spot-on at 6 mg/kg as a topical spot-on preparation

• Cross-infection with dogs and cats in the same household may occur.

• Ticks

• Unlikely in captive APH; common in wild hedgehogs of all species

• Manual removal; may need general anesthetic to allow access to all areas if high tick burden

• Ivermectin at 0.2 mg/kg SC or topically repeat after 2 weeks

• Note: Ticks in both APH and EH are implicated in harboring rickettsial infections.

• Myiasis

• Physical removal of maggots

• Ivermectin 0.2 to 0.5 mg/kg SC once only, but can be repeated after 2 weeks.

• Fluids

• Covering antibiosis; analgesics

• Neoplasia

• Surgical resection

• Some may respond to chemotherapy. Consult contemporary small animal protocols according to histopathologic classification.

• Epitheliotropic T-cell lymphoma: May respond to chemotherapy if diagnosed sufficiently early

• Pododermatitis

• Radiography to assess underlying bone involvement

• Clean and debride if appropriate.

• Covering antibiosis

• Analgesia

• Soft substrate

• Otitis externa

• Systemic antibiosis/antifungals according to culture

• Topical otic preparations if tympanic membrane known to be intact

• Pinnal dermatitis

• No one etiology identified; associated variously with dermatophytosis (see above), acariasis (see “Mites” above), nutritional deficiency, low-humidity conditions, and dry skin

• Cutaneous emphysema

• Etiology often difficult to ascertain; may be linked to mediastinal injury (e.g., rib fracture), allowing air to escape subcutaneously; deep-seated gas-producing infections

• Air/gas in subcutaneous tissues

• Release/aspirate gas aseptically; may need to be repeated

• Covering antibiosis and analgesia

• Foot and mouth disease—see Gastrointestinal Tract Disorders

Respiratory tract disorders

Bacterial

• Pasteurella

• Corynebacterium

• Bordetella bronchisepticum

Fungal

• Histoplasmosis (see Splenic Disorders)

Parasitic

• Capillaria aerophilum (EH)

• Crenosoma striatum (EH)

Neoplasia

• Bronchoalveolar carcinoma

• Squamous cell carcinoma

• Pulmonary adenocarcinoma

Other noninfectious problems

• Aspiration pneumonia (Pei-Chi et al 2015)

• Pulmonary hemorrhage (Pei-Chi et al 2015)

• Cardiac disease (see Cardiovascular Disorders)

Findings on clinical examination

• Dyspnea

• Respiratory noise

• Nasal discharge

• Lethargy

• Inappetence

• Sudden death

Investigations

1. Tracheal wash/bronchoalveolar lavage

2. Fecal microscopy (lungworm eggs)

3. Culture and sensitivity

4. Cytology

5. Pleural tap and cytology

6. Radiography

7. Endoscopy

8. Biopsy

9. Ultrasonography

Management

1. Supportive treatment (e.g., fluids, covering antibiosis)

2. Reduce stress levels. Hospitalize away from dogs and noisy cats; keep in darkened position.

TreatmentZspecific therapy

• Bacterial pneumonia

• Appropriate antibiosis

• NSAIDs

• High-oxygen environment

• Mucolytics may be useful.

• Lungworms

• Consider covering antibiosis and NSAIDs, as rapid die-offs of worms following treatment can cause serious lung damage and increase risk of pneumonia.

• Ivermectin at 0.2 mg/kg PO topically body weight; repeat after 2 weeks.

• Fenbendazole at 50 mg/kg PO body weight; repeat after 2 weeks.

• Crenosoma spp. carried by snails. Prepatent period of 21 days before eggs are shed. Prevent access to mollusk hosts. Crenosoma can cross placental barrier.

Gastrointestinal tract disorders

Permanent dental formula

A. albiventris and E. europeus

In A. albiventris the deciduous teeth begin to erupt at 18 days and are complete by 9 weeks old. The permanent teeth begin to erupt at around age 7 to 9 weeks. The upper incisors slot into a gap between the lower incisors, which are forward-projecting.

Disorders of the oral cavity

An anesthetic will be required for a good oral examination

• Dental disease

• Periodontal disease

- Antibiosis

- Tartar removal under general anesthetic

- Dental extractions

Fig 6-2. A good oral exam on a hedgehog requires an anesthetic. This hedgehog lost an upper incisor; the resultant tooth root abscess caused a unilateral discharge that triggered the initial presentation.

- Attempt prophylaxis by feeding self-cleaning, abrasive diets such as chitinous insects, adding charcoal or powdered bone to feed, or hard kibble.

• Fractured tooth

- Extraction

• Tooth root abscess

- Extraction

- Antibiosis

• Mandibular osteomyelitis

- Actinomyces naeslundii (Martinez et al 2005)

- Appropriate antibiosis (e.g., potentiated sulfonamides)

- High risk of systemic spread

• Bone cysts (mandibular swelling)

• Neoplasia

- Undifferentiated sarcoma (Fig. 6-3)

• Neoplasia

• Squamous cell carcinoma

• Poorly differentiated tumor

• Fibrosarcoma plasmacytoma

• Mucoepidermoid carcinoma of the parotid gland (Pei-Chi et al 2015)

Fig 6-3. Hedgehog exhibiting an undifferentiated sarcoma of the gums of the lower mandible visible as an asymmetric swelling of the mandible.

Differential diagnoses for gastrointestinal disorders

Viral

• Foot and mouth disease

• Parvovirus

Bacterial

• Bacterial enteritis

• Salmonella

Fungal

Protozoal

• Cryptosporidium erinacei (Kvac et al 2014a)

• Eimeria rastegaiv

• Isospora erinacei

Parasitic

• Nematodes

• Capillaria erinacei

• Capillaria spp.

• Physaloptera spp. (stomach worms)

• Gonglyonema spp. (esophageal worms)

• Acanthocephalans (thorny-headed worms)

• Echinorhynchus erinacei; E. roase (EU)

• Moniliformis cestodiformis, M. moniliform (APH)

• Hymenolepis erinacei (tapeworm)

• Brachylaemus erinacei (fluke)

Nutritional

• Milk (lactose intolerance)

• Dietary indiscretion

Neoplasia

• Squamous cell carcinoma (oral)

• Fibrosarcoma plasmacytoma (oral)

• Plasmacytoma (intestinal)

• Acinic cell carcinoma (intestine)

• Adenocarcinoma

• Intestinal lymphosarcoma

Other noninfectious problems

• Foreign body (e.g., carpet fibers)

• Gastric ulceration (Pei-Chi et al 2015)

• Gastroesophageal intussusception (Lee and Park 2012)

• Megaesophagus (Lee and Park 2012)

• Liver disease

Findings on clinical examination

• Diarrhea

• Green mucoid diarrhea (Capillaria spp.)

• Reduced or absent feces (obstruction, constipation, inappetence)

• Vesicular lesions on the tongue, snout, and feet (foot and mouth disease)

• Sudden death (Cryptosporidium)

• Anorexia, vomiting, collapse (foreign body)

• Hemorrhagic diarrhea (lymphosarcoma)

• Melena, restlessness (flukes)

• Vesicular and abraided lesions on tongue, around muzzle, feet, and perineum (foot and mouth disease)

Investigations

1. Fecal examination

a. MZN staining for Cryptosporidium

b. Bipolar eggs (Capillaria spp.—but see also lungworm in Respiratory Tract Disorders)

c. Proglottids (tapeworm)

d. Unipolar eggs (flukes)

e. Grass seedlike worms; embryonated eggs with hooks visible (acanthocephalans)

2. Radiography

a. Foreign body

3. Routine hematology and biochemistry

a. Pronounced leukocytosis with neutrophilia and lymphocytosis (intestinal lymphosarcoma—Helmer 2000)

4. Culture and sensitivity

5. PCR (parvovirus)

6. Endoscopy

7. Biopsy

8. Ultrasonography

Management

1. Fluid therapy (see Nursing Care)

2. If vomiting:

a. Do not feed for around 6 hours and use antiemetics (e.g., metoclopramide at 0.2 to 1.0 mg/kg SC t.i.d.

b. Monitor blood glucose; consider dextrose/saline fluids.

TreatmentZspecific therapy

• Foot and mouth disease

• Notifiable in United Kingdom, and reportable in United States

• Euthanasia

• Parvovirus

• Symptomatic treatment

• Bacterial enteritis

• See “Management” above.

• Appropriate antibiosis

• Salmonella

• Potentially zoonotic

• Discuss implications of zoonotic risk with owner.

• Cryptosporidium

• Often subclinical, but described as a cause of sudden death (Graczyk et al 1998). Postmortem revealed a catarrhal gastroenteritis.

• Prepatent period 4 to 5 days; patent period >20 days (Kvac et al 2014a)

• No effective treatment recognized

• Potentiated sulfonamides may be of use, as may nitazoxanide at 5 mg/kg PO s.i.d.

• Potential zoonosis (Kvac et al 2014b), so consider euthanasia.

• Eimeria and Isospora

• Toltrazuril at 10 mg/kg PO daily for 2 days, repeated weekly for 3 weeks

• Potentiated sulfonamides

• Capillaria spp.

• As for lungworm in Respiratory Tract Disorders

• Acanthocephalans

• Praziquantel at 25 mg/kg PO

• Covering antibiosis and analgesia for heavy burdens

• Tapeworm

• Usually asymptomatic

• Prevent access to beetles (intermediate hosts).

• Praziquantel at 5 to 10 mg/kg PO or SC; repeat monthly if required.

• Fluke

• As for tapeworm

• Foreign body

• Likely to need surgical removal

• Gastric ulceration

• As for other species: Consider antibiosis, H₂ blockers (e.g., cimetidine, ranitidine), and gastroprotectants (e.g., sucralfate).

• Gastroesophageal intussusception

• Attempt surgical correction; poor prognosis

• Treat underlying causes, typically esophagitis.

Nutritional disorders

Hedgehogs are invertebrate predators with omnivore leanings, so the natural diet of hedge­hogs consists largely of invertebrates such as insects and terrestrial mollusks, with some fruits and roots taken. Recommended fat and protein levels are 5% and 22%, but with mealworms having 33% fat and 53% protein, offering a diet largely of these commercially available insects is likely to lead to obesity. In addition there is a risk of hypocalcemia unless balanced with suitable calcium supplements. Hence the following recommendations are made:

Hedgehog nutrition

1. Low-calorie dry cat or dog kibble foods are recommended. The dental self-cleaning nature of these foods helps to reduce dental disease (see Gastrointestinal Tract Disorders'), and the lower calorific value reduces the risk of obesity.

2. Only a small percentage of insect-based foods such as mealworms should be offered.

3. A small proportion of vegetable material is recommended.

4. Adjust portion size to that consumed overnight.

• Obesity

• Common with captive diets; likely an imbalance between high caloric intake and reduced energy expenditure (reduced exercise, nonbreeding, nonhibernation)

• Weigh weekly and record the weights so as to avoid obesity.

• Limit amount offered so that all is consumed overnight with none left over.

• Hypoglycemia from starvation (see Pancreatic Disorders for management)

• Hepatic lipidosis

• Linked to anorexia, especially in obese individuals

• Aggressive fluid therapy

• Parenteral nutrition with glucose and vitamins

• Assisted feeding by syringe (see Nursing Care)

• Calcium gluconate PO or propylene glycol PO may be of use.

• Dexamethasone at 0.2 mg/kg IV, SC, or PO once only

• Thiamine (vitamin B₁) deficiency

• Possibly linked to feeding diets deficient in or compromised for vitamin B₁ (e.g., frozen milk) or due to chronic gut environment abnormalities (e.g., diarrhea)

• Signs include weight loss, ataxia and paresis, lethargy, and muscle weakness.

• Vitamin B complex at 1 to 2 mg/kg thiamine content as needed IM

• Supplement with thiamine at 300 mg/hedgehog/day.

• Hypovitaminosis A (see Ophthalmic Disorders)

• Hypovitaminosis D₃

• Stunted growth, shortened deformed limbs, squatting gait

• Anorexia, ataxia, hyperpnea, weight loss, diarrhea

• Deformation of vertebrae and ribs; pathological fractures of long bones

• Biochemistry (Table 6-3)

• Supplement with dietary vitamin D₃ and calcium.

Hepatic disorders

Viral

• Herpesvirus (EH)

Nutritional

• Hepatic lipidosis

• Ketosis (see Reproductive Disorders)

Neoplasia

• Lymphoma/lymphosarcoma (see Systemic Disorders)

• Metastases (e.g., insulinoma)

• Hemangiosarcoma

• Adenocarcinoma

• Hepatocellular adenoma

• Hepatocellular carcinoma

• Bile duct cyst adenoma

• Biliary carcinoma

Other noninfectious problems

• Lymphocytic hepatitis

• Cholangiohepatitis

• Chylous ascites (Roh et al 2014)

• Cirrhosis (Roh et al 2014)

Findings on clinical examination

• Reduced appetite or loss of appetite

• Vague signs of ill health

• Abnormal feces

• Hepatomegaly

• Jaundice (rare)

• Ascites

• Bile-tinged (green) diarrhea

• Seizures

Investigations

1. Radiography

2. Routine hematology and biochemistry

3. Culture and sensitivity

4. Abdominal tap

a. Milky white fluid with triglyceride Enalapril at 1.0 mg/kg PO every 24 hours (Delk et al 2013)

- Benazepril 0.25 to 0.5 mg/kg PO daily should be considered; less nephrotoxic than enalapril

- Pimobendan at 0.3 mg/kg PO b.i.d.

- L-carnitine at 50 mg/kg PO b.i.d. (Delk et al 2013)

• Hypertrophic cardiomyopathy

- Atenolol at 0.5 to 2.0 mg/kg PO daily

- Diltiazem at 0.5 to 1.0 mg/kg PO b.i.d.

• Valvular heart disease

• Treat as for dilated cardiomyopathy

• Erythropoietic porphyria

• Treat symptomatically.

• Wolff et al (2005) report affected hedgehog showed few signs of ill health. Lack of expected photodermatitis possibly due to nocturnal nature of APH.

• Presumed autosomal recessive as in other species

• Bacterial infections

• Appropriate antibiosis

Systemic disorders

Viral

• Retrovirus (possible cause of lymphoma)

• Pneumonia virus of mice (PVM—Madarame et al 2014)

• Herpesvirus

Bacterial

• Bacteremia/septicemia

• Mycobacteriosis

• M. bovis

Fungal

• Histoplasma capsulatum (see Splenic Disorders)

Nutritional

Neoplasia

• Lymphosarcoma (multicentric, gastrointestinal)

• Myeloproliferative disease/myelogenous leukemia

Other noninfectious problems

• Torpor (see Neurologic Disorders)

• Levamisole toxicity

Findings on clinical examination

• Weight loss

• Hind-leg weakness (wobbly hedgehog syndrome, intervertebral disease—see Neurologic Disorders)

• Chronic upper respiratory infections, dyspnea, general lethargy, wasting, and lymphadenopathy (lymphoma)

• Palpable abdominal masses (splenomegaly, mesenteric and/or gastric lymph nodes—lymphoma)

• Seizures

• Ataxia

• Circling

• Hyperesthesia, twitching, dyspnea, hypersalivation, and possibly cyanosis (levamisole toxicity, metaldehyde poisoning)

• Bluish colored feces or vomit (metaldehyde poisoning)

• Sudden death; signs of pain and discomfort and rapid death (herpesvirus)

Investigations

1. Radiography

a. Mediastinal masses, pleural effusions, abdominal masses (lymphoma)

2. Routine hematology and biochemistry

3. Bone marrow aspirate/lymph node cytology (lymphoma)

4. Abdominal centesis and cytology

5. Culture and sensitivity

6. Endoscopy

7. Biopsy/necropsy

a. Lymphoma (especially mesenteric lymph node, peripheral lymph nodes, spleen, liver, and any abnormal organs)

8. Ultrasonography

Management

• See Nursing Care.

TreatmentZspecific therapy

• Rabies

• Significant zoonosis. Euthanize.

• Bacteremia/septicemia

• Appropriate antibiosis

• Supportive therapy as necessary (see Nursing Care)

• Mycobacteriosis

• Zoonosis; notifiable in UK

• Euthanasia

• Lymphoma/lymphosarcoma

• Chemotherapy protocols for small animals are regularly altered and updated, so if in doubt, consult a veterinary oncologist.

• Palliative treatment for lymphoma:

- Prednisolone at 0.5 mg/kg PO b.i.d., increasing to control signs. Note: Prednisolone treatment alone is likely to make the lymphoma refractory to chemotherapy.

- Regular annual CBC to screen for lymphoma

• PMV

• Recorded as strongly suspected cause of encephalitis by Madarame et al 2014

• Levamisole toxicity

• Treat symptomatically.

• Metaldehyde poisoning

• Typically seen in EH following direct ingestion of slug bait; indirect ingestion

(i.e., consumption of poisoned slugs) appears to have minimal effects.

• Control hyperesthesia/convulsions (e.g., diazepam at 2 to 3 mg/kg SC, PO, per rectum body weight).

• Consider apomorphine as an emetic.

• Supportive therapy (e.g., fluids, gastric lavage)

• Herpesvirus

• If diagnosed antemortem, consider acyclovir or famciclovir.

• Poor prognosis

Musculoskeletal disorders

A unique property of hedgehogs is their ability to roll into an almost closed ball and position their spines into an erect position. This is achieved by a combination of the frontodorsalis and caudodorsalis muscles, which respectively move the spines down over the rump and forehead. The panniculus carnosus muscle rolls the hedgehog up, while the orbicularis muscle pulls the mantle of spines together like a drawstring.

Bacterial

• Myositis

Parasitic

• Pentastomids

• Lingulata spp.

• Armillifer armillatus

Neoplasia

• Osteosarcoma (Benoit-Biancamano et al 2006; Rhody and Schiller 2006)

Other noninfectious problems

• Bone cysts (see Gastrointestinal Disorders)

• Traumatic fractures

• Orbicularis muscle prolapse

• Osteoarthritis

• Foreign body/annular fiber around digit/extremity

• Any causes of weakness

• See Neurologic Disorders

• See Cardiac and Hematologic Disorders

• See Systemic Disorders

• See Pancreatic Disorders

Findings on clinical examination

• Pain

• Lameness

• Swelling

• Hind-leg paresis/paralysis

• Mandibular swelling (bone cysts)

• Self-mutilation of hind feet (spinal osteosarcoma—Rhody and Schiller 2006)

• Apparent paralysis; the hind legs and pelvis protrude backward and sideways from below spiny coat, with the tail and anus pulled up over the back. The orbicularis muscle is found to lie above (dorsal to) the pelvis (orbicularis muscle prolapse).

Investigations

1. Radiography

a. Osteolysis, pathological fractures (multiple myeloma)

b. Spinal cord compression (osteosarcoma)

2. Traumatic fractures

3. Routine hematology and biochemistry

4. Culture and sensitivity

5. Endoscopy

6. Biopsy

7. Ultrasonography

TreatmentZspecific therapy

• Traumatic fractures

• Repair using standard small animal techniques.

• May respond well to strict rest (close confinement), especially if bone density suspect (See “Hypovitaminosis D₃" in Nutritional Disorders)

• Neoplasia

• Surgical resection, amputation, chemotherapy, or radiation therapy as for other small animals

• Annular fiber

• Remove under general anesthesia; may require digital amputation if extremity not considered viable

• Pentastomids

• Incidental finding in peritoneum

• Surgical removal

• Osteoarthritis

• Analgesics/antiinflammatories (see “Analgesia” in Nursing Care)

• Myositis

• If bacterial, use appropriate antibiosis; otherwise analgesia

• Orbicularis muscle prolapse

• Under anesthesia, pull the muscle back into position. It will usually stay in place.

Neurologic disorders

Viral

• Herpes simplex virus 1 • Rabies

Bacterial

• Bacterial meningitis or other CNS infection

• Otitis media/interna

Nutritional

• Hypoglycemia

• Thiamine deficiency (see Nutritional Disorders)

• Malnutrition (see “Hedgehog Nutrition” in Nutritional Disorders)

Neoplasia

• Cortical carcinoma (of the nerve sheath)

• Schwannoma

• Lymphoma (Burballa et al 2012)

Other noninfectious problems

• Toxins

• Trauma

• Torpor

• Intervertebral disc disease (Raymond et al 2009)

• Other spinal lesions (e.g., fractures)

• Wobbly hedgehog syndrome

Findings on clinical examination

• Apparent weakness

• Posterior paralysis/paresis

• Seizures

• Otitis externa (see also “Ear Mites” in Skin Disorders)

• Exposure to possible source of herpes simplex (e.g., owner with cold sores)

Investigations

1. Full neurologic examination

2. Radiography

a. Intervertebral disc collapse, spondylosis (intervertebral disc disease)

3. Routine hematology and biochemistry

4. Serology for toxoplasmosis

5. Culture and sensitivity

6. Endoscopy

7. Biopsy

8. Ultrasonography

Management

• Important to differentiate from other causes of weakness (insulinoma, lymphoma, etc.)

TreatmentZspecific therapy

• Herpes simplex virus 1

• Unlikely to be diagnosed premortem

• If diagnosed, attempt treatment with oral lysine at 250-500 mg/kg PO or acyclovir at 40 to 100 mg/kg PO daily.

• Rabies

• Significant zoonosis; euthanasia

• Bacterial CNS infection

• Appropriate antibiosis

• Supportive care

• Fungal infections see Dermatophytosis in Skin disorders

• Hypoglycemia

• For management of hypoglycemic episodes, see Pancreatic Disorders.

• Orthopedic conditions

• Treat as for other small animals.

• Torpor

• Check environmental temperatures. For APH it should be above 18° C.

• Hedgehogs will initially use external heat sources to begin reversal of torpor before initiating physiologic heat generation.

• During torpor, hedgehogs do not thermoregulate but allow their body temperature to fluctuate with the ambient temperature.

• In the related A. frontalis, torpor is believed to be an energy-saving strategy rather than directly linked to low temperatures (Hallam and Mzilikazi 2011); lighter individuals had shorter bouts of torpor than heavier ones, possibly due to reduced levels of fat reserves.

• Wobbly hedgehog syndrome

• Progressive hind-limb ataxia and muscle wastage

• Eventually tetraparesis

• Death within 18 to 25 months following onset of signs

• Ameliorative treatment—consider NSAIDs, B vitamin supplementation.

• Unknown etiology. Some lines appear more susceptible than others, suggesting a genetic predisposition.

• Intervertebral disc disease

• NSAIDs

• Surgical decompression

Ophthalmic disorders

Hedgehogs have shallow orbits and large eyelid fissures, which can predispose them to prop­tosis, especially combined with excessive amounts of retrobulbar fat due to obesity.

Bacterial

• Salmonella spp.

• Mycobacterium spp.

• Osteomyelitis of the nares/socket

Protozoal

Nutritional

• Obesity

• Hypovitaminosis A

Neoplasia

• Carcinoma of the ocular globe

• Acinic cell carcinoma (Fukuzawa et al 2004)

Other noninfectious problems

• Idiopathic cataracts

• Retinal degeneration

• Foreign body

• Trauma

Findings on clinical examination

• Corneal ulceration

• Conjunctivitis

• Nasal discharge

• Uveitis

• Corneal edema, hypopyon, and synechiae

• Cataracts

• Exophthalmos proptosis (obesity, retrobulbar lesion, acinic cell carcinoma, panophthalmitis)

• Megaglobus/glaucoma

• Cataracts

• Keratoconjunctivitis sicca, conical deformation of eyeball, and discoloration (hypovitaminosis A)

Investigations

1. Ophthalmic examination

2. Schirmer tear test (STT)

a. In long-eared hedgehogs (Hemiechinus auritus), the mean STT = 1.7 ±

1.2 mm/1 min with a range of 0 to 4 mm/1 min. For males the STT was 2.2 ± 1.2 mm/1 min; for females, 1.3 ± 1.1 mm/1 min (Ghaffari et al 2012).

3. Topical fluorescein to assess extent of ulceration

4. Tonometry

5. In long-eared hedgehogs (Hemiechinus auritus), the intraocular pressure (IOP) = 20.1 ± 4.0 mm Hg (range, 11.5 to 26.5 mm Hg). For males the IOP was 18.2 ± 4.0 mm Hg; females, 22.0 ± 3.2 mm Hg (Ghaffari et al 2012).

6. Skull radiography

7. Routine hematology and biochemistry

8. Culture and sensitivity

9. Biopsy

10. Ultrasonography

TreatmentZspecific therapy

• Proptosis

• Typically involves orbital cellulitis, corneal perforation, and panophthalmitis (Wheler et al 2001). The lens may be absent, extruded through a corneal lesion.

• Enucleation

• Covering antibiosis

• Consider protective tarsorraphy of the remaining eye, as bilateral proptosis is possible.

• Corneal ulceration

• Topical and systemic antibiosis

• Once infection cleared, treat as for other small animals (e.g., scarification to encourage healing, conjunctival grafts etc.).

• Uveitis

• Topical ophthalmic steroid or NSAID preparations

• Topical ophthalmic antibiotic preparations plus systemic antibiosis if appropriate

• Enucleation if severe

• Cataracts

• Treat for any uveitis as above.

• Cataract removal either surgically or by phacoemulsification

• Neoplasia

• Enucleation

• Hypovitaminosis A

• Supplement with vitamin A.

• Topical lubricants and antibiosis if keratoconjunctivitis sicca present

Endocrine disorders

Neoplasia

• C-cell carcinoma (thyroid gland)

• Follicular adenoma (pituitary gland)

• Adenocarcinoma (parathyroid gland)

• Adrenal adenoma

• Adrenocortical carcinoma (Juan-Salles et al 2006)

• Pheochromocytoma

Findings on clinical examination

• Palapable mass on ventral neck (thyroid carcinoma)

• Dysphagia, weight loss, tetraplegia (thyroid carcinoma—Miller et al 2002)

Investigations

1. Radiography

2. Routine hematology and biochemistry

a. Thyroxine (T₄) in EH varies with season from 2.4 nmol/L (winter) to 16.0 nmol/L (summer)—Augee et al 1979

3. Low-dose dexamethasone suppression test (hyperadrenocortism)

4. Culture and sensitivity

5. Endoscopy

6. Biopsy

7. Ultrasonography

TreatmentZspecific therapy

• Hyperadrenocorticism

• Trilostane at 2.0 mg/kg PO daily initially, can increase to 6.0 mg/kg daily

Urinary disorders

Bacterial

• Cystitis

• Leptospirosis

Neoplasia

• Lymphoma (see Systemic Disorders)

Other noninfectious problems

• Urolithiasis

• Cystitis

• Nephrosis

• Intrarenal calcinosis

• Renal calculi

• Nephritis

• Nephrocalcinosis

• Tubular necrosis

• Glomerulosclerosis

• Renal infarcts

• Glomerulonephropathy

Findings on clinical examination

• Depression

• Anorexia

• Weight loss

• Polydipsia/polyuria

• Oral ulceration

• Hematuria (urolithiasis, cystitis, uterine neoplasia, endometrial polyps—see Reproductive

Disorders)

• Hind-leg weakness

• Melena

• Dysuria/polyuria

• Pinkish urine (erythropoietic porphyria—see Cardiovascular and Hematologic Disorders)

• Urine dribbling, wet perineum, constant licking at genitalia (urolithiasis)

• Painful urination, stranguria (urolithiasis, cystitis)

• Green urine (leptospirosis)

• Death

• Palpable abnormalities

• Distended bladder (urethral obstruction)

Investigations

1. Urinalysis (normal urine parameters, see Table 6-6)

a. Ketonuria (ketosis—see Reproductive Disorders)

b. Leptospires may be seen in urine.

2. Radiography

a. Useful to differentiate uncomplicated cystitis from urolithiasis

b. Contrast studies (pyelography, double contrast bladder studies, pneumocystography)

3. Routine hematology and biochemistry (Table 6-7)

a. Serology for leptospirosis

4. Cytology

5. Culture and sensitivity

6. Endoscopy

7. Biopsy

8. Ultrasonography

Management

1. Fluid therapy (see Nursing Care)

2. Reduction of proteinuria with angiotensin retention blocker (e.g., telmisartan at

1 mg/kg PO once daily)

3. Anabolic steroids may be useful.

4. Appropriate antibiosis

TreatmentZspecific therapy

• Leptospirosis

• Often subclinical

• Experimental infection of EH with L. pomona (Webster 1957) causes intermittent fever, jaundice, and abortion.

• Appropriate antibiosis

• Urolithiasis

• May be linked to dried cat food-based diet

• If urethral obstruction:

- Attempt catheterization (can be difficult in males due to J-shaped os penis).

- Cystocentesis

- Surgical cystotomy

- If unable to clear urethra, create a perineal urethrostomy.

• Cystic calculi

• Cystotomy

• Submit any stones/sand for analysis.

• Antibiosis (usually has accompanying cystitis) and other supportive care

• May be linked to dried cat food-based diet

• Change diet based on results of stone analysis.

• Neoplasia

• Neoplasia of the bladder: Surgery difficult because it is often diffuse. Chemotherapy may prove useful.

Reproductive disorders

Females have two pairs of nipples on the chest and one on the abdomen; some females may have extra. Ovulation is induced.

Bacterial

• Mastitis

Nutritional

• Ketosis/pregnancy toxemia

Neoplasia

• Mammary tumors

• Granulosa cell tumor

• Adenoma/adenosarcoma

• Leiomyosarcoma

• Adenocarcinoma

• Adenoleiomyosarcoma

• Spindle cell tumor

• Neurofibrosarcoma

• Endometrial stromal sarcomas

• Endometrial polyps

Other noninfectious problems

• Dystocia

• Physical abnormalities

• Large hoglets

• Maternal pelvic abnormalities

Findings on clinical examination

• Hemorrhagic vaginal discharge (endometrial polyps, uterine/vaginal neoplasia)

• Swollen, painful, discolored mammary glands (acute mastitis, neoplasia)

• Swollen but otherwise normal mammary glands (chronic mastitis)

• Lethargy and dehydration in pregnant female. Melena may be present (pregnancy toxemia).

Investigations

1. Radiography

2. Routine hematology and biochemistry

3. Urinalysis

a. Ketonuria (ketosis)

4. Culture and sensitivity

5. Endoscopy

6. Biopsy

7. Ultrasonography

Management

1. Fluid therapy (see Nursing Care)

2. Prophylactic antibiotics

TreatmentZspecific therapy

• Mastitis

• Acute mastitis

- Antibiosis and fluids

- NSAIDs may have antiendotoxin effects (see “Analgesia” in Nursing Care).

- Debride or surgically resect affected mammary tissue.

- Fostering of young may spread pathogens to other females.

• Chronic mastitis

- Often nonresponsive to therapy.

• Ketosis

• Usually linked to period of anorexia/starvation during pregnancy

• In some cases linked to large litters

• Supportive treatment, including fluids, warmth, and IV glucose/force feeding (see Nursing Care)

• Perform cesarean as soon as possible.

• Foster or euthanize young as they are hard to hand-rear and recovering female is unlikely to lactate.

• Dystocia

• Large or deformed hoglets, pelvic abnormalities, and other anomalies

• If pelvis normal, consider 0.2 to 3.0 units oxytocin SC, IM. If no result, either repeat treatment or undertake cesarean.

• Cesarean

Neonatal disorders

• Some normal parameters of hedgehog neonates are shown in Table 6-8.

Other noninfectious problems

• Hypothermia (especially up to 100 g body weight, after which the hoglets become more active and are better thermoregulators)

• Lack of maternal milk

• Mastitis (see Reproductive Disorders)

• Maternal systemic illness

• Maternal aggression/cannibalism

Findings on clinical examination

• Lethargy

• Failure to feed

• History of lack of maternal care

• Failure to grow

• Diarrhea (may not be apparent as female continually licks clean)

Investigations

1. Weigh young.

2. Radiography

3. Routine hematology and biochemistry

4. Culture and sensitivity

5. Endoscopy

6. Biopsy

7. Ultrasonography

Management

• Nursing care, especially provision of warmth and fluids, is extremely important with neonates.

TreatmentZspecific therapy

• Lack of maternal milk production

• Hedgehogs have been raised on a variety of milk replacers, including artificial bitch and cat milk and goat milk.

• Hypothermia

• Place in warm environment initially, with temperatures up to 35° C.