
In 2018, the U.S. Food and Drug Administration, acting on input from a group of veterinary researchers, began investigating whether the increasing popularity of grain-free dog foods had led to a sudden rise in a potentially fatal heart disease in dogs, dilated cardiomyopathy.
Four years later, the FDA has found no firm link between diet and dilated cardiomyopathy. Nor has it rejected such a link, and research is ongoing. Publicity surrounding this issue, nevertheless, has shrunk the once-promising market for grain-free dog foods.