Associations of diet and breed with recurrence of calcium oxalate cystic calculi in dogs

Objective-To evaluate the long-term risk of recurrence of calcium oxalate (CaOx) cystic calculi in dogs of various breeds fed 1 of 2 therapeutic diets. Design-Retrospective cohort study. Animals-135 dogs with a history of CaOx cystic calculi. Procedures-Medical records for 4 referral hospitals were searched to identify dogs that had had CaOx cystic calculi removed. Owners were contacted and medical records evaluated to obtain information on postoperative diet, recurrence of signs of lower urinary tract disease, and recurrence of cystic calculi. Dogs were grouped on the basis of breed (high-risk breeds, low-risk breeds, and Miniature Schnauzers) and diet fed after removal of cystic calculi (diet A, diet B, and any other diet [diet C], with diets A and B being therapeutic diets formulated to prevent recurrence of CaOx calculi). Results-Breed group was a significant predictor of calculi recurrence (as determined by abdominal radiography or ultrasonography), with Miniature Schnauzers having 3 times the risk of recurrence as did dogs of other breeds. Dogs in diet group A had a lower prevalence of recurrence than did dogs in diet group C, but this difference was not significant in multivariable analysis. Conclusions and Clinical Relevance-Results indicated that Miniature Schnauzers had a higher risk of CaOx cystic calculi recurrence than did dogs of other breeds. In addition, findings suggested that diet may play a role in decreasing recurrence, but future prospective studies are needed to validate these observations.