Taurine and carnitine deficiencies are associated with dilated cardiomyopathy (DCM) in dogs, but little is known about other diet-related etiologies. Recognition of DCM in atypical breeds fed grain-free diets (GFD) prompted this study.
Diet histories and echocardiograms from dogs diagnosed with DCM at NCSU from 2015-2017 were evaluated. Dogs were grouped by diet into GFD and non-grain-free (NGFD) groups. The GFD group was subdivided into dogs fed the most common brand (GFD-1) or other brands (GFD-o). Echocardiographic parameters were compared between groups<./p>
Of 22 dogs with DCM fed GFD, 10 received GFD-1, including 2 pairs of unrelated housemates. No taurine or carnitine deficiencies were identified among the GFD dogs tested (11 taurine, 4 carnitine). Twenty-seven dogs with DCM were fed NGFD. Of these, 5 of 11 tested were taurine deficient (3 vegetarian). Dogs eating GFD-1 weighed less (23.1 ± 11.5kg); had greater normalized LV diameter in diastole (LVIDdN), 2.55 ± 0.26; and systole (LVIDsN) 2.05 ± 0.30; and lower sphericity index (SI) 1.24 ± 0.09 compared to dogs eating GFD-o (weight 35.9 ± 13.0kg, p = 0.03; LVIDdN 2.26 ± 0.33, p = 0.04; LVIDsN 1.79 ± 0.28, p = 0.05; SI 1.38 ± 0.18, p = 0.03) and compared to dogs eating NGFD (weight 33.5 ± 13.7, p = 0.04; LVIDdN 2.13 ± 0.23, p < 0.0001; LVIDsN 1.71 ± 0.21, p = 0.0006; SI 1.43 ± 0.20, p = 0.001). Dogs eating GFD regardless of brand had greater LVIDdN (p = 0.0019), greater LVIDsN (p = 0.012) and lower SI (P = 0.016) than dogs eating NGFD. Prevalence of congestive heart failure was not different between GFD and NGFD groups<./p>
Echocardiograms of dogs with DCM fed GFD, and specifically GFD-1, suggest more advanced disease or a diet-enhanced pathophysiology compared to dogs eating NGFD.