Diagnosis and management of malabsorption in dogs

Malabsorption can result from interference with either the degradation or absorption phases in the handling of dietary constituents and represents an important cause of weight loss and diarrhoea in dogs. Effective treatment depends on identification and understanding of the underlying disease which could affect the functional capacity of the exocrine pancreas or small intestine. Exocrine pancreatic insufficiency (EPI) can be identified by a low concentration of trypsin-like immunoreactivity in serum and results in serious malabsorption due to interference with degradation of carbohydrate, protein and fat. Treatment with oral pancreatic extract complemented by a low fat, high quality protein diet, is effective in many cases. Refractory cases may need additional treatment with an oral antibiotic for small intestinal bacterial overgrowth (SIBO), and H₂-receptor blockers to help prevent denaturation of the pancreatic extract by stomach acid. The pancreas plays a key role in the normal absorption of cobalamin (vitamin B₁₂) in dogs and malabsorption of cobalamin in EPI may not resolve with treatment so that cobalamin may need to be given parenterally. Small intestinal disease may result in interference with the number or functioning of individual enterocytes, in some cases accompanied by cellular infiltration of the mucosa. Diagnosis depends on indirect assessment of intestinal damage, for example by assay of serum vitamins and determination of intestinal absorption and permeability, and in selected cases followed by endoscopic examination, intestinal biopsy and culture of duodenal juice. Treatment depends on the disease and may include oral antibiotic for SIBO and immunosuppressive drugs for infiltrative disease. Dietary management is also important, for example with a restricted fat diet containing highly digestible carbohydrate and high quality protein, and when a dietary sensitivity is suspected a restriction diet of a selected protein source may be needed.