High prevalence of gastric trichobezoars (hair balls) in Wistar-Kyoto rats fed a semi-purified diet.

Gastric trichobezoars (hair balls) are frequently found in rabbits but are rarely reported in rats. Several Wistar-Kyoto rats fed a semi-purified diet developed anorexia and abdominal tenderness. Proteolysis therapy with fresh papaya and commercially prepared enzyme was attempted in these rats but was not successful. The prevalence of trichobezoars at necropsy was 100%. We conclude that semi-purified diets contribute to trichobezoar formation in rats, but proteolysis therapy is not effective in dissolving the trichobezoars.