General physical examination

1.2.2.1 Skeletal growth and development

A failure to grow in dogs and cats, often seen with endocrino- pathies such as Eyposomatotropism and hypothyroidism, can also result from vascular ring or other esophageal anomalies, malabsorption, or portosystemic shunts (Figure 1.6).

1.2.2.2 Body condition

Measurement of body weight is inexpensive, easy, and very useful. Weight loss can be caused by inadequate nutrient assi­milation (anorexia, regurgitation, vomiting, maldigestion, or malabsorption), increased loss of nutrients (protein-losing ne­phropathy [PLN] and/or protein-losing enteropathy [PLE]), and /or increased energy demand, as it occurs in hyperthyroid cats or febrile patients. Cachexia associated with fever can be due to infectious (e.g., FIP, FeLV), inflammatory (e.g., pan­creatitis and others), or neoplastic (e.g., gastrointestinal neo­plasia, lymphoma) causes.

Weight loss is unusual in patients with diarrhea due to large bowel disease, but it can be seen in patients with severe, long­standing colitis such as histiocytic ulcerative colitis (HUC), cecocolic intussusception, or diffuse colorectal neoplasia.² However, it could also be caused by the tendency of owners to fast a pet with diarrhea.

It is very important to remember that an acute decrease in body weight can be due to water loss (i.e., vomiting and /or diarrhea) and that measurement of body weight will allow an accurate assessment of the level of dehydration.

1.2.2.3 Mental status

Depression or stupor can be related to abnormal brain func­tion caused by metabolic (e.g., hepatic encephalopathy or acid-base and osmolality imbalances), inflammatory (e.g., ca­nine distemper, FIP, sepsis), and vascular (e. g., coagulopathies, hypertension) disorders.

1.2.2.4 Abnormalities in posture and locomotion

In the cat, neck ventroflexion can be a sign of hypokalemia that can be caused by gastrointestinal loss of potassium due to vomiting, diarrhea, or anorexia.

1.2.2.5 Mucous membranes

Mucous membrane color and capillary refill time (CRT) are used to estimate peripheral perfusion. A slower CRT suggests either dehydration or high peripheral sympathetic tone and vasoconstriction. Both are associated with low cardiac output. In a patient presented for vomiting, diarrhea, and /or anorexia, it is very important to address the patient’s overall hydration status. To that end, the clinician should assess body weight, skin turgor or pliability, moistness and color of the mucous mem­branes, CRT, position of the eyes in their orbits, and the pulse and respiratory rates and their characteristics.

Pale mucous membranes are a manifestation of either de­creased red blood cell mass or decreased peripheral perfusion. In the latter case, shock (i. e., hypovolemic, cardiogenic, or va­somotor shock) can cause hypovolemia, cardiac insufficiency, and vasoconstriction. As a result pallor is a hallmark of shock. In patients with endotoxemic shock, the mucous membranes may become cool to the touch.

Pale mucous membranes can also be associated with hepato­biliary disease due to increased consumption and/or as an effect of non-regenerative anemia due to chronic disease. Pep­tic and neoplastic gastric ulceration may also lead to anemia. Acute blood loss into the abdomen due to visceral hemangi­osarcoma (HSA), which occurs much more frequently in dogs than cats, can also cause pale mucous membranes, weakness, abdominal distension, and increased pulse and respiration rates. The CRT is normal for anemic patients unless hypoperfusion is also present.

Also, the oral and ocular mucous membranes are often the first sites where jaundice can be seen. Yellow oral mucus mem­branes are almost always observed in cases of severe icterus and can be caused by immune-mediated hemolytic anemia or hepatobiliary disease.

A septic patient often has injected, highly vascular mucous membranes (brick-red) as can also occur in polycythemic pa­tients, or those with acute hepatic and pancreatic disease, or severe azotemia. Congestion of mucous membranes may occur in patients with gastrointestinal disease, usually as a manifesta­tion of dehydration. Mucous membranes should also be checked for signs of hemorrhage. Superficial bleeding into the skin or mucous membranes, and scleral and vitreal hemorrhage are often common manifestations of abnormalities of primary hemostasis. In addition to petechiae or ecchymoses, the animal may also present with hematemesis and melena as well as he­maturia. Although infrequent, patients with severe hepatic dis­ease can show bleeding diathesis due to coagulation factor de­ficiency, disseminated intravascular coagulation (DIC), or portal hypertension. Because of the multiple hemostatic defects present in patients with DIC, they may experience hemor­rhage of any type and in any location (cavitary or superficial).

1.2.2.6 Peripheral lymph nodes

1 Mandibular, prescapular, and popliteal lymph nodes are usually palpable and they should be evaluated for size, shape, and con­sistency. The axillary and superficial inguinal lymph nodes are not always discernible. Given the close proximity of the man­dibular lymph nodes and submaxillary salivary glands, it is es­sential that the clinician be able to distinguish between the two. Especially in cats, the surrounding subcutaneous fat may make the popliteal lymph nodes seem larger than their actual size. On the other hand, emaciated adult animals may have normal-sized popliteal lymph nodes that appear more promi­nent because of loss of fat and muscle mass.

Generalized lymphadenopathy usually indicates a systemic disease (e. g., immune-mediated disease, systemic infection, or more commonly neoplasia). Especially in the dog, the pres­ence of markedly enlarged external lymph nodes that are firm and non-painful, is highly suggestive of lymphoma.⁴

1.2.2.7 Skin and subcutaneous tissue

The skin should be carefully inspected for areas of alopecia, inflammation, nodularity, and crustiness.

Non-seasonal pruritus, erythema, and papules can be attrib­uted to food hypersensitivity or “intolerance” in both dogs and cats. Concurrent presence of gastrointestinal and derma­tological signs in dogs and cats is strongly suggestive of food hypersensitivity.^8-12

Dramatic skin lesions (i.e., erythema, crusts, erosions, ulcers, alopecia, or shiny skin) can be seen in high-contact areas and on the ventral thorax and abdomen in patients with superficial necrolytic dermatitis, which can be caused by liver disease or glucagonoma. Also, pancreatic tumors have been reported as a cause of alopecia in dogs and cats.¹³

The integument should also be evaluated for changes in skin turgor, which is assessed in a consistent manner and location, usually on the lateral thorax. In evaluating skin turgor, the clinician should take into account the fact that skin turgor is dependent on the amount of subcutaneous fat and elastin, as well as on the interstitial volume. Thus, emaciated and older animals may appear more dehydrated than they actually are. On the other hand, obese animals may appear falsely well- hydrated based on their skin tenting.

Generalized soft tissue swelling or enlargement involving the four limbs, often associated with ascites, may be due to edema. Edema can be easily distinguished from other subcutaneous fluid accumulations or masses because pressure applied to an edematous area results in an indentation that stays for a short period of time. Subcutaneous edema can occasionally be seen in hypoalbuminemic dogs with PLE, PLN, or severe hepatic insufficiency.

1.2.2.8 Bodytemperature

At the time the temperature is taken, the clinician should also note if the rectal area is clean or soiled from diarrhea or mat­ting, and whether the anal sacs are distended.

Hematochezia (i. e., fresh blood in the stool) is strongly sugges­tive of large bowel disease, in particular colitis. However, enter­ocolic and cecocolic intussusception, colorectal neoplasia and coagulopathies, especially platelet disorders, must also be con­sidered, even though these are uncommon. Melena describes tar-, coal-, or asphalt-colored stools, resulting from digested blood and can be observed due to bleeding into the pharynx, esophagus, stomach, or upper small bowel. When melena is present, a complete physical examination should include care­ful inspection of the nares, oropharynx, and lungs for evidence of the source of bleeding. It is important to remember that a life-threatening volume of blood can accumulate within the gastrointestinal tract, with little or no visible signs of external blood loss. If gastrointestinal blood loss is associated with acute diarrhea, regardless of its cause, this signals a loss of normal intestinal mucosal integrity. With the loss of this barrier, the normal enteric flora can cross into the bloodstream, leading to septicemia. In this case, the clinician needs to address this life­threatening complication of diarrhea, while determining its cause.

There are many causes of fever in patients with gastrointestinal disease, ranging from infectious diseases (e.g., FeLV, FIV, FIP, canine distemper, feline panleukopenia, canine parvovirus, leptospirosis, salmonellosis, toxoplasmosis, leishmaniasis, histo­plasmosis, blastomycosis, cryptococcosis, coccidiodomycosis, or rickettsial infections) to disorders involving the liver, exo­crine pancreas, and the peritoneum, or neoplasia such as lym­phoma or carcinoma.

In contrast, severely uremic patients, patients with sepsis and shock, or patients in the final stages of several severe systemic diseases can be hypothermic.

1.2.2.9 Pulse rate

The effects of many systemic and metabolic diseases on car­diac structure and function are well recognized. In some cases these may constitute the major clinical concern, while in oth­ers these effects may be subtle or of minimal importance. Common causes of tachycardia are excitement, fever, anemia, hemorrhage, shock, hypotension, significant alterations in the concentration of electrolytes or acid-base balance, congestive heart failure, and some infections.

Patients with GDV often show cardiac dysfunction, especially after surgical decompression. This is often associated with tachyarrhythmias or, less commonly, bradyarrhythmias.

Septic shock, often caused by gram-negative bacteria, can re­sult in brick-red mucus membranes with a strong pulse during the initial stages, or pale mucus membranes and a weak pulse during the latter stages.

Electrolyte and acid-base abnormalities can produce signi­ficant alterations in cardiac function. These can often be documented during examination of the pulse; but are bet­ter recorded using an ECG. Severe hyperkalemia (usually >8 mEq/L) causes severe cardiac dysfunction. In addition to hypoadrenocorticism, hyperkalemia with hyponatremia (Na/K ratios the animal while it is drinking or eating. Tonsillitis or enlargement of the tonsils, mainly in the dog, can cause anorexia, vomiting, or dysphagia, and can occasionally be a sign of systemic disease (e. g., lymphoma). The tongue is examined for color and move­ment. The underside of the tongue is checked for masses, string foreign bodies (in the cat), or a laceration of the frenu­lum as a result of a string.

The odor of the breath can be indicative of dental or perio­dontal disease, but also of uremia or ketonemia.

The high frequency of hyperthyroidism in geriatric cats obliges the clinician to carefully palpate the paratracheal area, extending from the caudal larynx to the thoracic inlet, in order to detect nodular swelling suggestive of thyroid gland enlarge­ment. The normal feline thyroid glands cannot be palpated.

Abdominal effusion is usually caused by hypoalbuminemia, portal hypertension, or peritoneal inflammation. Effusion due to gastrointestinal disease is primarily caused by PLE, hepatic failure, rupture of the alimentary tract, or leakage following anastomosis.^16,17 PLE in a young dog with chronic intermit­tent diarrhea, without hookworms, should prompt suspicion of a chronic intussusception and an abdominal ultrasound should be performed.¹⁸

Pyogranulomatous inflammation of the abdominal or thoracic cavity that is associated with a characteristic effusion is typical for the effusive form of FIP.

Malignant abdominal tumors may lead to obstruction of lymphatic flow, increased vascular permeability, accumulation of a modified transudate, or development of non-septic peri­tonitis. Modified transudates can also result from hepatic or cardiac disease. Hepatobiliary malignancies or other intra-ab- dominal malignant forms of neoplasia that have spread to the peritoneum can elicit an inflammatory reaction, with subse­quent exudation of lymph, fibrin, and blood. This fluid may be serosanguinous, hemorrhagic, or pseudochylous in appear­ance.

Enlarged organs that most often account for increased ab­dominal size are the liver, spleen, and occasionally, the kidneys. Alternatively, single neoplastic masses of other organs also fre­quently lead to abdominal distension.

Abdominal palpation is the cornerstone of the physical ex­amination in dogs and cats with clinical signs of gastrointesti­nal disease. This can be a most informative procedure for the cat, because of the ease with which most of the viscera can be palpated in this species.

If a gas-distended abdomen is suspected, digital abdominal percussion should be performed, listening for a tympanic sound. A sudden onset of a gas-distended abdomen, shock, and even death are often observed in dogs with intestinal vol­vulus.

Some animals tense their abdominal muscles in response to palpation. It is essential to determine whether this is caused by pain, anxiety, or the exertion of too much pressure during palpation. More significance is attributed to the pain response elicited in stoic animals and to pain that is localizable, repeat­able, and evident after minimal manipulation. It is necessary to determine whether the painful area is superficial, located in the cranial or caudal abdomen, and whether it originates from a specific viscus. Cranial abdominal pain is commonly ob­served in dogs with pancreatitis, but less commonly observed in cats. Generalized abdominal pain with rigidity of the ab­dominal musculature suggests generalized peritonitis.

It is worth noting that if an animal arches its back during ab­dominal palpation the primary problem may be in the spinal cord. The empty stomach in cats and dogs is usually only pal­pable in thin patients, although if distended with food, it can be palpated in the upper left abdominal quadrant in most pa­tients. The gallbladder and pancreas are not normally palpable. However, in patients with pancreatitis, pancreatic neoplasia, or a pancreatic pseudocyst, an abdominal mass and pain associ­ated with palpation of the mass may be observed in the right cranial quadrant of the abdomen.

The small intestine is easily palpated as a thin-walled and smooth object that fills much of the mid-abdomen, and slides through the fingers. In the cat, the ileocecal area can often be palpated as a firm, knot-like structure in the mid-cranial abdo­men, and should not be confused with an abdominal mass. The bowel should be carefully evaluated for thickness, rigidity, and irregular masses. A thickened intestinal wall may be felt in patients with intestinal infiltration by inflammatory or neo­plastic cells and in patients with intestinal smooth muscle hypertrophy.¹⁹

Masses (e.g., lymph node enlargements, foreign bodies, omental steatitis, neoplasia, intussusception, or focal granulo­matous lesions, such as those that can be seen in patients with a non-effusive form of FIP) can cause partial or total intestinal obstruction, but may go undetected during physical examina­tion because of their small size.²⁰ Fluid-distended small bowel loops are often palpable in patients with acute enteritis. Ag­gregated or accordion-like small bowel loops are characteristic of a linear foreign body obstruction in cats. Palpable me­senteric lymph node enlargements are often associated with tumors, granulomas, or intestinal inflammation (with or with­out foreign body obstruction). A massive mesenteric lym­phadenopathy is often typical of dogs and cats with alimentary tract lymphoma, but modest lymphadenopathy can also be found in patients with IBD or other chronic intestinal dis­eases.

A sick animal that vomits shortly after abdominal palpation should be suspected of having a GI obstruction, severe GI tract inflammation, or pancreatitis.

The transverse and descending colon are often full of fecal material and can easily be identified by palpation of the mid­posterior abdomen, just ventral to the spine. An impacted co­lon (the colon must be at least twice its normal diameter be­fore megacolon can be considered), is caused by intestinal obstruction or dysmotilities.

The liver can be palpated routinely just caudal to the costal arch along the ventral body wall in both canine and feline patients, but may not be palpable in some cases. If the liver is not palpable, it does not automatically mean that it is abnor­mally small. Microhepatia is mainly seen in patients with a congenital portosystemic shunt or those with chronic hepatic disease with progressive loss of hepatocytes. However, hepatic size is better evaluated by radiography. In lean cats, it is possible to palpate the diaphragmatic surface of the liver. In animals with pleural effusion or other diseases that expand the thoracic volume, the liver may appear enlarged due to caudal displace­ment. The pattern of hepatic enlargement may be generalized or focal depending on its cause. Infiltrative and congestive dis­eases tend to result in smooth, firm, and diffuse hepatomegaly. Primary or metastatic neoplasia, nodular hyperplasia, and some chronic hepatic diseases associated with nodular regeneration can cause focal or asymmetric hepatic enlargement.

In icteric dogs and cats, hepatosplenomegaly may be attribut­able to mononuclear-phagocytic cell hyperplasia and ex­tramedullary hematopoiesis secondary to immune-mediated hemolytic anemia or to infiltrative processes such as systemic mast cell disease, lymphoma, or myeloid leukemia.

Palpation of the spleen is not always possible, but sometimes the free distal portion is palpable on the floor of the mid-ab­domen. The spleen is palpated for identification of an increase in size and for nodules or larger masses. In patients with severe splenomegaly, the spleen may occupy the entire ventral ab­dominal floor.²¹ When the enlarged spleen is folded over, it may be mistaken for a mass. With experience, the clinican can sometimes unfold the spleen with his or her thumb, and thus the “real” shape of the organ can be evaluated.

The kidneys can only be easily palpated in cats because they are more loosely attached than they are in dogs. The kidneys are normally located in the retroperitoneal area, and the right kidney lies slightly more cranial than the left. The kidneys are evaluated for size, shape, location, firmness, pain, and surface irregularities. The left kidney (the only one that can be pal­pated in some dogs) is especially movable and can easily be mistaken for an abdominal mass. Enlarged, abnormally-shaped kidneys may be caused by acute renal failure, renal neoplasia, renal cysts, abscesses, granulomatous nephritis due to FIP, hydronephrosis, or hematoma. In contrast, small renal size is often associated with chronic renal disease.

During abdominal palpation of intact female animals, the normal non-gravid uterus is usually non-palpable. Massive Uteromegaly caused by pregnancy, pyometra, mucometra, or hydrometra can sometimes give the mistaken impression of ascites and must be carefully differentiated.

Lastly, abdominal auscultation may sometimes be helpful. Fail­ure to detect intestinal sounds after two or three minutes of auscultation is suggestive of ileus.

The perineal area should be examined for evidence of di­arrhea caked in the hair coat, masses, or herniations. Rectal examination must always be performed and the clinician should be able to identify and evaluate the colonic mucosa, anal sphincter, anal sacs, pelvic canal bones, urogenital tract, and luminal contents. Mucosal polyps can easily be misinter­preted as mucosal folds, and it is possible to miss partial stric­tures that are large enough to allow a single finger to pass through.

Pelvic canal obstruction due to congenital and acquired causes can lead to constipation and megacolon, especially in cats.

Rectal discomfort, hematochezia, and mucous can be found in patients with colitis, proctitis, or large bowel neoplasia as de­scribed previously.

During the rectal examination, the prostate of all mature male dogs must be evaluated for size, symmetry, surface structure, and pain. If enlarged, the prostate may extend slightly over the brim of the pelvis or fall into the abdomen. In this latter situ­ation, the prostate can be palpated in the caudal abdomen ventral to the colon and caudal to the urinary bladder. To assist in rectal palpation, the other hand of the examiner should be used to gently push the prostate into a more dorsal and caudal position via abdominal palpation.

Also, in order to complete the physical examination, the clini­cian should observe the act of defecation whenever possible, especially if there is a history of dyschezia or tenesmus.

Whether tenesmus occurs before or after defecation can also aid in differentiation of the underlying disease process. Ob­structive disorders are more commonly associated with tenes­mus before evacuation of feces, whereas inflammatory disor­ders are often associated with persistent tenesmus after the evacuation of feces.

Key Facts

■ A life-threatening volume of blood can accumulate within the gastrointestinal tract, with little or no visible signs of external blood loss.

■ Abdominal distension may be due to gas, fluid, organomegaly, or poor abdominal muscle tone.

■ PLE in a young dog with chronic intermittent diarrhea, without hookworms, should prompt a suspicion of chronic intussuscep­tion.

■ Aggregated (accordion-like) small bowel loops on abdominal palpation are characteristic of a linear foreign body obstruction in cats.

■ A sick animal that vomits shortly after abdominal palpation should be suspected of having a GI obstruction, severe GI tract inflam­mation, or pancreatitis.

■ Rectal examination should be performed in every patient presenting for evaluation of gastrointestinal disease.

References

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2. Hostutler RA, Luria BJ, Johnson SE et al. Antibiotic-responsive his­tiocytic ulcerative colitis in 9 dogs.J Vet Intern Med 2004; 18: 499­504.

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9. White SD, Sequoia D. Food hypersensitivity in cats: 14 cases (1982­1987). J Am Vet Med Assoc 1989; 194: 692-695.

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14. Guilford WG. Approach to clinical problems in gastroenterology. In: Guilford WG, Center SA, Strombeck DR, Williams DA, Meyer DJ (eds.), StrombeckS Small animal gastroenterology, 3rd ed. Philadelphia, WB Saunders, 1996; 50-76.

15. Bissett SA, Lamb M, Ward CR. Hyponatremia and hyperkalemia associated with peritoneal effusion in four cats. J Am Vet Med Assoc 2001; 218: 1590-1592.

16. Hinton LE, McLoughlin MA, Johnson SE et al. Spontaneous gas­troduodenal perforation in 16 dogs and 7 cats (1982-1999). J Am Anim Hosp Assoc 2000, 38: 176-187.

17. Ralphs SC, Jessen CR, Lipowitz AJ. Risk factors for leakage follow­ing intestinal anastomosis in dogs and cats: 115 cases (1991-2000). J Am Vet Med Assoc 2003; 223: 73-77.

18. Peterson PB, Willard MD. Protein-losing enteropathies. Vet Clin North Am (Small Anim Pract) 2003; 33: 1061-1082.

19. Diana A, Pietra M, Guglielmini C et al. Ultrasonographic and path­ologic features of intestinal smooth muscle hypertrophy in four cats. Vet Radiol Ultrasound 2003; 44: 566-569.

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21. de Morais HA, O'Brien T. Non-neoplastic disorders of the spleen. In: Ettinger SJ, Feldman EC (eds.), Textbook of Veterinary Internal Medicine, 6th ed. Philadelphia, Elsevier Saunders, 2005; 1944-1951.

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