Grain-free diets gained popularity from a belief that grains are unnatural or allergenic for pets. In reality, true grain allergies are rare in dogs and cats; protein sources like beef, dairy, and chicken are far more common triggers. Grains like brown rice and oats are well-digested carbohydrate and fiber sources for most pets. In 2018, the FDA began investigating a potential link between certain grain-free diets high in legumes and potatoes and dilated cardiomyopathy (DCM) in dogs. Research is ongoing and no definitive cause has been established, but many veterinary nutritionists recommend grain-inclusive diets from established manufacturers unless a specific medical reason exists. Always consult your veterinarian before switching to or from grain-free food.