Diets with no or low amounts of dietary fiber can reduce small intestinal ulcers induced by non-steroidal anti-inflammatory drugs in dogs.

Recent progress in endoscopic techniques has revealed that non-steroidal anti-inflammatory drugs (NSAIDs) often cause ulcers in the small intestine in humans, but effective therapy is not available at present. In the present study, we investigated the effects of feeding condition and the amount of dietary fiber (DF) in the diet on the formation of gastrointestinal ulcers induced by NSAIDs in dogs. Several types of diets containing various percentages of DF were given to dogs. Indomethacin (1 or 3 mg/kg, p.o.), ketoprofen (2 mg/kg, s.c.), or fulnixin (1 mg/kg, s.c.) was administered once daily at 10 a.m. after a morning meal or without a morning meal (fasted condition) for 3 - 7 days. Gastrointestinal lesions were examined 24 h after the final dose of the drugs. When indomethacin (3 mg/kg) was administered after a morning meal (fed condition) for 7 days, it produced many lesions in the small intestine. However, when it was given in the fasted condition without the morning meal, the lesions were markedly decreased. All the NSAIDs given after feeding of regular dry food containing 6% DF once a day for 3 days produced many lesions in the small intestine. The lesions were decreased or increased in dogs given prescription diets containing low DF (1.1%) and high DF (15.4%), respectively. Furthermore, lesions were not observed in dogs given canned diet containing very low DF (< 0.1%), whereas lesions appeared again in dogs given canned diet supplemented with cellulose (3 or 10%) but not with pectin (10%). These results suggested that both feeding condition and insoluble DF, such as cellulose in the diet, play an important role in the formation of NSAID-induced small intestinal lesions, and that a diet with no or low amounts of DF may decrease gastrointestinal side-effects associated with the use of NSAIDs.