Page 1037 - Small Animal Clinical Nutrition 5th Edition

Chapter
58

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Protein-Losing

Enteropathies

Deborah J. Davenport
Albert E. Jergens
Rebecca L. Remillard

“Lymph, v.: to walk with a lisp.”
From a Washington Post reader submission word contest

lymphangiectasia are generally attributable to the loss of lymph
CLINICAL IMPORTANCE constituents (i.e., albumin, lymphocytes, fat) or to the underly-
ing enteric disease. Many patients present with chronic inter-
Protein-losing enteropathy (PLE) is a broad term encompassing mittent diarrhea or vomiting; however, not all have GI signs.
intestinal disorders characterized by gastrointestinal (GI) pro- Progressive weight loss, often in the face of a good appetite, is
tein loss of such magnitude as to result in hypoalbuminemia. a consistent finding in longstanding cases. Excessive protein
Lymphangiectasia is one form of PLE. Lymphangiectasia is loss from leaky intestinal lymphatics results in hypoalbumine-
characterized by abnormalities of the intestinal lymphatic sys- mia and loss of colloidal oncotic pressure. External manifesta-
tem, which cause lymphatic hypertension. Lymphangiectasia tions of hypoalbuminemia may include pitting edema, ascites
may occur as a primary lymphatic defect or as a consequence of and pleural effusion. In some cases, chylous effusions of the
severe intestinal infiltrative disease (e.g., inflammatory bowel abdomen, subcutis or thoracic cavity may occur in conjunction
disease, alimentary lymphosarcoma, fungal enteritis). Lymph- with primary or congenital lymphangiectasia (Fossum et al,
angiectasia is a common cause of PLE in dogs. PLE in cats is 1987, 1990, 1992) Rarely, affected dogs may present with
rare. Collectively, PLE is a relatively uncommon manifestation thromboembolic phenomena (e.g., pulmonary thromboem-
of diarrheic disorders in dogs and cats. bolism) as a consequence of antithrombin III deficiency. Severe
hypocalcemia due to malabsorption in affected dogs can cause
PATIENT ASSESSMENT tetany and rarely seizures.
Physical examination findings may be unremarkable in dogs
History and Physical Examination with PLE. Patients with severe hypoproteinemia may present
Typically, signs of lymphangiectasia are insidious in onset and with dyspnea and abdominal enlargement due to accumulation
follow a waxing and waning course over several weeks to of fluid in the thoracic or abdominal cavities, respectively.
months before becoming overt. The clinical manifestations of Pitting edema of the limbs may be noted. Body condition