Protein-losing enteropathy secondary to intestinal lymphangiectasia was diagnosed in a 1 1/2 -year-old female Doberman Pinscher. Poor growth rate, intermittent diarrhea, ascites, edema, hypoproteinemia, grossly dilated intestinal lymphatics, and impaired fat absorption characterized the disease. There was histopathologic evidence of dilatation of lacteals and excessive chromium (51Cr)-labeled human albumin in the feces following its intravenous administration. Sixteen weeks of a special diet (high in carbohydrates and medium-chain triglycerides; low in long-chain triglycerides) led to remission of clinical signs. Serum albumin increased over its initial value of 1.09 to 1.7 g/dl, while serum globulin increased from 1.71 to 1.9 g/dl. Following 9 months of dietary therapy, serum albumin increased to 2.1 g/dl and serum globulin increased to 2.6 g/dl.