Intestinal malabsorption and cryptosporidiosis in an adult dog.

Chronic intestinal cryptosporidiosis was diagnosed as the cause of chronic diarrhea and weight loss in an adult dog without obvious signs of immunosuppression. Results of tests for digestive function suggested that the dog had impaired intestinal absorption or bacterial overgrowth. The nutrient malabsorption might have resulted in or have been caused by the cryptosporidiosis. Temporary clinical improvement without reduction in fecal oocyst concentration was noticed following treatment with clindamycin. The dog was euthanatized. At necropsy, the dog was found to have chronic lymphoplasmacytic enteritis and cryptosporidiosis. A veterinary student that worked in the ward where the dog was kept developed cryptosporidal diarrhea.