Gastrointestinal phycomycosis in 63 dogs.

In a study of 63 cases of canine gastrointestinal phycomycosis, 60 were determined to have pythiosis and 3 to have entomophthoromycosis. In pythiosis, male, large-breed dogs less than or equal to 3 years old were most commonly affected. Clinical signs usually included vomiting and weight loss and these were associated with lesions of the stomach and small intestine. Histologically, the causative organisms were found in necrotic regions of diffuse or discrete granulomas in the submucosa or muscularis mucosae. Entomophthoromycosis was diagnosed by finding wide eosinophilic sleeves intimately surrounding thin-walled hyphae. Less than 5% of the dogs were alive 3 months following diagnosis.