Grain-Free Dog Food and Heart Disease: What to Know

Reviewed by a veterinarian · Last reviewed October 16, 2026

The short answer: grain-free diets haven't been proven to cause heart disease in dogs, but a possible link has been under study since 2018, and the question isn't settled. Most dogs don't need a grain-free diet. Unless your vet has recommended one for a specific reason, a well-made food that includes grains is a sensible choice, and that's why the picks on BestBowl include grains.

What the concern is about

The heart condition in question is dilated cardiomyopathy (DCM), a disease where the heart muscle weakens and the heart enlarges, so it pumps less effectively. DCM can lead to heart failure.

DCM has long been known to run in certain breeds, such as Doberman Pinschers, Great Danes, Boxers, Irish Wolfhounds, Golden Retrievers, and Cocker Spaniels. In 2018, veterinary cardiologists began noticing it in dogs of breeds not usually affected, many of whom were eating grain-free diets or diets high in peas, lentils, other legumes, or potatoes.

What the FDA found

In July 2018, the FDA announced it was investigating reports of DCM in dogs eating certain diets. Over the next few years:

The FDA received about 1,400 reports of DCM in dogs between 2014 and late 2022.
In the reports it analyzed, more than 90% of the foods involved were grain-free, and most listed peas or lentils among their main ingredients.
Some dogs improved after their diet was changed, along with medical treatment.

In December 2022, the FDA said it did not have enough data to show that these foods caused DCM, and that it would stop issuing routine public updates until there is meaningful new science to share. The agency still reviews reports, and research by veterinary cardiologists and nutritionists is ongoing.

In plain terms: a pattern was found, a cause was not proven, and the question remains open.

Why "grain-free" may not be the whole story

Grains themselves probably aren't the issue. Researchers are looking at what replaces the grains in these foods, especially high amounts of peas, lentils, and other legumes, and how those ingredients might affect heart health in some dogs. Taurine, an amino acid important for heart muscle, is part of the investigation too, though many affected dogs had normal taurine levels.

So the label "grain-free" is a rough flag, not a precise one. A food can include grains and still be heavy in legumes, and a grain-free food isn't automatically a problem.

Does my dog need grain-free food?

For most dogs, no. Grain-free became popular through marketing, not because dogs commonly have trouble with grains. True grain allergies are uncommon; when dogs do have food allergies, the trigger is more often a protein such as beef, chicken, or dairy.

Many veterinary nutritionists suggest:

Choosing a food that includes grains, unless your vet recommends otherwise for a specific reason
Avoiding foods where peas, lentils, other legumes, or potatoes appear high on the ingredient list
Picking brands that employ a board-certified veterinary nutritionist and test their foods

If your dog eats grain-free food now

You don't need to panic, and you don't need to change foods overnight. If you'd like to switch to a grain-inclusive food, transition gradually over about a week to avoid stomach upset.

It's worth a conversation with your vet, especially if your dog is a breed predisposed to DCM or has eaten a grain-free, legume-rich diet for a long time. Your vet can listen to your dog's heart and decide whether further testing, such as an echocardiogram, makes sense.