Effects of prednisone alone or prednisone with ultralow-dose aspirin on the gastroduodenal mucosa of healthy dogs.

BACKGROUND The coadministration of prednisone and ultralow-dose aspirin has been recommended for the management of various diseases, but the safety of this combination in dogs has not been studied. HYPOTHESES The gastroduodenal lesions associated with prednisone and ultralow-dose aspirin administration will be similar to those caused by prednisone alone, but both treatments will result in more severe lesions than placebo. ANIMALS Eighteen healthy adult purpose-bred dogs. METHODS Randomized, blinded, placebo-controlled study of 3 treatment groups for 27 days: placebo, prednisone, and prednisone and aspirin. Gastroduodenoscopy was performed before and on days 5, 14, and 27 of treatment and mucosal lesions scores were assigned. Mucosal lesion scores were compared by a Kruskal-Wallis test. Clinical signs were compared by the Friedman's chi-square test (significance at P < .05). RESULTS There were no significant differences in the gastroduodenal lesion scores among groups, or within groups at any time during the study. Significantly more dog-days of diarrhea occurred in the prednisone and aspirin group during treatment, compared with baseline. No significant differences in clinical signs were found among any of the groups. CONCLUSION The concurrent use of prednisone and ultralow-dose aspirin did not increase the severity of gastroduodenal lesions compared with prednisone or placebo. Coadministration of prednisone and ultralow-dose aspirin increases the frequency of mild, self-limiting diarrhea in some dogs.