[anonymous]

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

17. What’s the safest diet for my dog?
Different dogs have different nutritional needs based on a number of factors, so nutrition advice is not one-size-fits-all. The FDA recommends asking your veterinarian, who may consult a board-certified or veterinary nutritionist, for advice about what to feed your dog.
It’s important to note that the reports include dogs that have eaten grain-free and grain containing foods and also include vegetarian or vegan formulations. They also include all forms of diets: kibble, canned, raw and home-cooked. Therefore, we do not think these cases can be explained simply by whether or not they contain grains, or by brand or manufacturer.
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.

http://skeptvet.com/Blog/2019/06/fda-update-on-grain-free-diets-and-heart-disease-in-dogs/ excerpt below, click on link for article and comments

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.