Why Veterinarians are Leery of Grain-Free Diets

A possible link to Dilated Cardiomyopathy. Dilated Cardiomyopathy (DCM) is a life-threatening condition in which the heart muscle grows in size and the walls of the heart thin and weaken. The condition significantly decreases the heart’s ability to contract and effectively push blood throughout the body. Dogs with DCM may cough, show signs of exercise intolerance, and weight loss. In advanced stages of DCM, dogs can collapse or even die suddenly.


Before 2015, DCM in dogs was seen exclusively in breeds of dogs known to have a genetic predisposition to the disease, with Doberman pinschers seen as the poster child for the disease. Other known breeds of dogs affected by DCM (likely genetic in nature) were Great Danes, Irish Wolfhounds, Boxers, and Cocker Spaniels. It was exceedingly rare to see DCM in any other dog breed.


In 2015, the FDA began receiving reports from veterinarians across the US about a rising number of canine patients with DCM whose breed was not previously known to be predisposed to the condition. The FDA began to take notice of these incidents and noted a pattern - many of these dogs were on grain-free diets. The rising number of reported cases led the FDA to release an official statement in 2018 calling attention to the issue. Since then, the FDA and veterinary community have been tracking data and have noted that approximately 90% of the affected patients were on grain-free diets. These grain-free products did not contain corn, soy, barley, rice, and other grains. The diets did however have higher than historically used proportions of legume seeds, specifically; peas, chickpeas, and lentils, to make up for the lack of grain. It has been hypothesized that the high levels of these legumes in grain-free diets, in addition to other factors (genetics, and other underlying medical conditions), could potentially be the cause.


Many dog food companies have been upset by the release of this information without a proven cause and effect relationship between DCM and grain-free diets, and have even gone as far as to state that there is no link between the two. That, however, has been refuted by the FDA. As recently as November of 2020, the FDA stated "it is clear that this is a complex, multi-factorial scientific issue, and that, while a direct [cause and effect] link to diet has not been identified, the FDA has not eliminated diet as a potential factor. As the scientific community looks further into the role that diet may play in these cases, we hope to explore additional avenues about ingredient levels, bioavailability, ingredient sourcing, and diet processing to determine if there are any common factors."


Given all the information we currently have about DCM and its possible link to grain-free diets, it is this veterinarian's OPINION that if an animal does not have a specific medical reason to be on a grain-free diet, that grain-free diets be avoided in favor of their grain counterparts until more information can be gathered.



For more information on why to avoid grain-free diets for your dog, please don't hesitate to reach out to Evergreen Animal Hospital in Evergreen, Colorado at (303) 674-4331 today to schedule an appointment.