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This is one of the few pet food stories where the headline outran the evidence in both directions. It was first reported as grain-free food causes heart disease, and later as the FDA admits it was wrong. Neither is what happened.
Here is what the agency actually investigated, what it found, and where the question sits now.
What the FDA investigated
In July 2018 the FDA announced it was looking into reports of dilated cardiomyopathy, a disease in which the heart muscle weakens and the chambers enlarge, in dogs eating certain diets. Many of the diets were labelled grain free and contained a high proportion of peas, lentils, other pulses or potatoes as main ingredients.
DCM is a real and serious disease. In some breeds, Dobermanns and Great Danes among them, it is substantially genetic. The question was whether diet was causing it in breeds where it is not usually expected.
What the reports showed
The FDA identified 16 dog food brands with ten or more reported cases. Of the reported diets, more than 90 percent were grain free and 93 percent contained peas or lentils.
That pattern is what prompted the investigation. But when the agency tested the foods, it found the same average levels of protein, fat, taurine and taurine precursors as in foods containing grain. The obvious nutritional explanation did not hold up.
Reports are not a study. If most premium foods on the shelf were grain free during that period, most reported cases would be grain free even if the diet played no part. That is exactly the limitation the FDA points to in its own wording.
What the FDA says now
The agency stopped publishing updates on 23 December 2022. Its position is stated plainly on the investigation page: adverse event numbers can be a potential signal, but by themselves they do not supply sufficient data to establish a causal relationship with the reported products.
It describes the potential association between diet and DCM as a complex scientific issue that may involve multiple factors, and says it does not intend to release further public updates until there is meaningful new scientific information to share.
Researchers at veterinary schools have continued working on it. The question is open, not closed in either direction.
What a reasonable owner does with this
- Do not panic, and do not dismiss it. A possible signal that has not been explained is a reason for care, not for fear.
- Ask why you chose grain free. Genuine grain allergy in dogs is uncommon; most food allergies involve proteins. If there was no medical reason, there is little to lose by choosing otherwise.
- Prefer companies that employ a veterinary nutritionist and run feeding trials, whichever way they formulate.
- Know the signs of heart disease: coughing, tiring easily, faster breathing at rest, fainting. Any of those deserves a vet visit regardless of diet.
- If your breed is predisposed to DCM, discuss screening with your vet. That matters more than the ingredient panel.
The food label guide examines nutritional adequacy claims. The diagnostic estimate guide explains the costs of investigating a concern without selecting tests for a dog.
Questions people ask
Did the FDA confirm grain-free food causes DCM?
No. It investigated reports, found a pattern in them, and has stated that the reports do not supply sufficient data to establish a causal relationship.
Is grain-free dog food safe?
There is no finding that it is unsafe, and no finding that clears it either. If your dog has no medical reason to avoid grains, there is little benefit to offset the open question.
Should I switch my dog's food because of this?
Talk to your vet, particularly if your dog is a breed predisposed to heart disease. A diet change is low risk; making it for a considered reason is better than making it from a headline.
What are the signs of DCM in dogs?
Coughing, lethargy, exercise intolerance, faster breathing at rest, a swollen abdomen or fainting. These need veterinary assessment quickly, whatever the dog eats.
Where these figures come from
- FDA Investigation into Potential Link between Certain Diets and Canine Dilated Cardiomyopathy US Food and Drug Administration · fda.gov
- Until more science is available, FDA will end public updates on potential link between certain diets and canine dilated cardiomyopathy American Veterinary Medical Association · avma.org
Figures last checked September 2026.
