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.