“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.”

https://apnews.com/article/science-health-pets-dogs-us-food-and-drug-administration-adbe215e2ee660b57b1d01dfff8d5f40