A link between dilated cardiomyopathy (DCM) and dog foods marketed as grain-free has been suggested. In this randomized, parallel-group, double-blind study, the impact of 4 foods with different ingredient profiles on echocardiographic parameters and cardiac biomarkers was assessed in 60 dogs over 18 mo. Foods included a grain-free diet with potatoes and peas (GF + PPo), a grain-inclusive diet with peas and pea fiber (G + PPF), a grain-inclusive diet without peas or potatoes (G), and a grain-free diet with potatoes (GF + Po). Echocardiographic parameters, blood and urinary taurine, and serum cardiac troponin-I and NT-BNP were assessed at 6, 12, and 18 mo. No clinically significant changes or between-group differences were observed in cardiac troponin-I or NT-BNP. Whole blood and plasma taurine levels remained within the normal range and were unaffected by diet. Despite diet-by-time interactions in wLVIDd, wLVIDs, fractional shortening, and ejection fraction (P < 0.05), all dogs were considered clinically normal regarding DCM. Twenty-four dogs were diagnosed with mild endocarditis by study end, which may explain the observed echocardiographic changes. These data demonstrate that cardiac function was supported in healthy adult dogs fed foods formulated to provide similar nutrition through different ingredient profiles. These results demonstrate the importance and effectiveness of balanced, high-quality nutritional formulations.
Keywords: cardiac biomarkers; dilated cardiomyopathy; dogs; echocardiogram; grain-free diet; taurine.
Dilated cardiomyopathy (DCM) is the second most common heart disease in dogs. In recent years, concerns have been raised regarding the potential association of grain-free dog foods with the development of DCM. To evaluate the potential connection between diet and DCM, this study randomized healthy adult dogs to 1 of the 4 complete and balanced foods formulated with different ingredients to assess their impact on cardiac function and overall health over a period of 18 mo. Foods included a grain-free diet with potatoes and peas, a grain-inclusive diet with peas and pea fiber, a grain-inclusive diet without peas or potatoes, and a grain-free diet with potatoes. No changes in cardiac function were noted with grain-free or grain-inclusive foods, and taurine status was unaffected by diet. These results show that foods formulated to provide similar nutrition through different ingredients supported cardiac function in healthy adult dogs. This study highlights the importance of balanced, high-quality nutrition in dogs.
© The Author(s) 2025. Published by Oxford University Press on behalf of the American Society of Animal Science.