[anonymous]

https://www.fda.gov/animal-veterinary/animal-health-literacy/questions-answers-fda-center-veterinary-medicines-investigation-possible-connection-between-diet-and
excerpt below

To put this issue into proper context, the American Veterinary Medical Association estimates that there are 77 million pet dogs in the United States. As of April 30, 2019, the FDA has received reports about 560 dogs diagnosed with DCM suspected to be linked to diet. Tens of millions of dogs have been eating dog food without developing DCM. If you are concerned about the diet you are currently feeding your dog, FDA recommends working with your veterinarian, who may consult a board-certified veterinary nutritionist, to determine the best diet for your dog’s need.

FDA Update on Grain-free Diets and Heart Disease in Dogs

excerpts (out of context) below, click on link for full article and comments

The specific relationship between diet and DCM in these cases is not yet understood, so it is impossible to say if the food is a primary cause of DCM and, if so, how this is happening. However, the common thread among the diets involved seems to be the use of legumes or pulses (e.g. peas, lentils) in place of grains in the diet.

While many of the diets contain common protein sources (e.g. chicken and lamb), a surprisingly high proportion have unusual and uncommon meats as their main protein source. Again, the significance of this is not yet clear.

There is a concentration of cases among golden retrievers, though dogs of many other breeds have been affected as well.

Further data collection and research will be necessary to determine the precise relationship between diet and DCM in these cases. There are likely multiple factors involved, including the ingredients in the diet, the genetics or particular breeds and individuals, and others we may not yet know about. Pet owners feeding these diets don’t need to panic, since far more dogs on these diets do NOT have DCM than do. However, if you are feeding one of these foods, or a diet similar in composition, and especially if you are feeding this to a golden retriever, it would be a good idea to talk to your vet about screening your pet for DCM and considering a change in diet.