Adherent gram-positive cocci on the intestinal villi of two dogs with gastrointestinal disease.

Two dogs were examined for clinical signs of chronic gastrointestinal disease. Duodenal mucosal biopsy specimens, obtained endoscopically, revealed histologic lesions of adherent gram-positive cocci on the villus epithelium of both dogs. The positive gram stain and morphologic features of the adherent cocci were suggestive of Streptococcus organisms. Indirect tests for intestinal bacterial overgrowth were not diagnostic, suggesting that the adherent cocci were a primary lesion. Rapid clinical response following dietary manipulation and the initiation of medical management was observed in both dogs. The dogs of this report draw similarities to Streptococcus durans infection previously reported in pigs, foals, and a single pup. The pathogenesis of enteric disease associated with adherent gram-positive cocci in dogs remains ill-defined.