Dilated cardiomyopathy is a disease of the heart muscle that weakens its ability to pump blood. Some breeds (Doberman, Boxer, Cocker Spaniel, Great Dane) have known genetic predispositions. In 2018 the FDA opened an investigation after observing DCM in non-predisposed breeds, with a common factor of grain-free diets high in legumes (peas, lentils, chickpeas) and potatoes. The mechanism is unclear, possibly involving taurine metabolism. The FDA's current advice is to discuss diet choice with your vet, especially for at-risk breeds.