Page 1109 - Small Animal Clinical Nutrition 5th Edition

Chapter
68

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Hepatobiliary Disease

Hein P. Meyer
David C. Twedt

Philip Roudebush
Elizabeth Dill-Macky

“Life loves the liver of it.”
Maya Angelou

primary liver tumors) and chronic hepatitis account for more
CLINICAL IMPORTANCE than 60% of these patients (Rothuizen and Meyer, 2000).
Hereditary PSS occur in 2 to 5% of investigated breeds (Meyer
Among the most challenging problems in medicine are those et al, 1995).The liver may also be damaged secondarily by other
that involve failure of a metabolically active organ such as the disease processes. Resultant changes are often classified as a
liver. The liver is the second largest organ of the body and per- reactive hepatopathy. Because the liver plays an essential role in
forms an estimated 1,500 essential biochemical functions the metabolism of protein, carbohydrate and fat, nutritional
(Zakim, 1985). In addition to its role in drug metabolism, the support plays an essential role for many patients with hepato-
removal of environmental and endogenous noxious substances biliary disease.
and synthesis of important substances (e.g., albumin and blood The liver has tremendous storage capacity, functional reserve
clotting factors), the liver plays a key role in food digestion and and regenerative capabilities. All of these functions protect the
nutrient metabolism. The liver influences nutritional status body from profound metabolic alterations. However, these
through its elaboration of bile salts and central role in interme- same characteristics complicate the clinical recognition of seri-
diary metabolism of protein (amino acids), carbohydrate, fat and ous liver disease. Consequently, hepatobiliary disease must be
vitamins. Table 68-1 lists the most important hepatic functions. severe before clinical signs occur. As a result, the patient may be
Patients with hepatobiliary disease are often seen in compan- suffering longstanding and profound metabolic alterations by
ion animal practice. An estimated 2 to 3% of all animals pre- the time a diagnosis is made and an appropriate management
sented at a veterinary teaching hospital have some form of plan is implemented.
hepatobiliary disease (Meyer, 2000). Hereditary portosystemic The liver is also unique in that it derives its nutrient blood
shunts (PSS), tumors (metastasis, malignant lymphoma and supply from venous and arterial sources (Anderson and