Retrospective study of dilated cardiomyopathy in dogs

BACKGROUND: The United States Food and Drug Administration is investigating possible diet-associated dilated cardiomyopathy (DCM) in dogs and cats. OBJECTIVES: To retrospectively review DCM cases for signalment, diet information, echocardiographic changes, and survival. ANIMALS: Client-owned dogs (n = 71). METHODS: Medical records of dogs diagnosed with DCM between January 1, 2014 and September 30, 2018 were reviewed. Dogs were grouped into "traditional" or "nontraditional" diet categories and whether or not diet was changed after diagnosis. RESULTS: For dogs eating nontraditional diets, those that had their diets changed had a larger percentage decrease in normalized systolic left ventricular internal dimension (P = .03) and left atrial:aorta ratio (P < .001) compared to those that did not have their diets changed. Survival time was significantly longer for dogs with DCM eating nontraditional diets that had their diets changed (median survival, 337 days; range, 9-1307 days) compared to dogs eating nontraditional diets that did not have their diets changed (median survival, 215 days; range, 1-852 days; P = .002). CONCLUSIONS AND CLINICAL IMPORTANCE: Dogs with DCM eating nontraditional diets can experience improvement in cardiac function after diet change but additional research is needed to examine possible associations between diet and DCM.