Grain-Free Dog Food and DCM: What the FDA Investigated and What We Know Now

Starting in 2018, the FDA investigated reports of dilated cardiomyopathy (DCM), a serious heart muscle disease, in dogs eating certain diets, many of them labeled grain-free and high in peas, lentils or other legumes. The FDA has not established that these diets cause DCM, and in its last update in December 2022 said it did not plan further public updates until there is meaningful new scientific information. If you are unsure about your dog’s food, talk to your veterinarian.

This article explains what the FDA looked at, what remains uncertain and what practical steps owners can take.

What DCM is

DCM is a disease in which the heart muscle weakens and the heart enlarges, so it pumps less effectively. It can lead to congestive heart failure or irregular heart rhythms. Some large and giant breeds are genetically predisposed to DCM. What caught veterinarians’ attention around 2018 was a rise in reports from breeds not usually prone to it, often in dogs eating similar types of diets.

What the FDA investigation covered

The FDA’s Center for Veterinary Medicine collected reports from veterinarians and owners and published several updates. The main points from its investigation page and earlier updates:

• 2018: The FDA announced it was looking into reports of DCM in dogs eating certain pet foods, many containing peas, lentils, other legumes or potatoes as main ingredients.
• 2019: Updates summarized hundreds of reports. Most involved diets labeled grain-free, and most of those foods contained peas and/or lentils. The FDA also published the brand names most frequently mentioned in reports, which drew wide attention and debate.
• 2022: The FDA said that report counts alone did not supply enough data to establish a causal link with any product, described the issue as complex and possibly involving multiple factors, and said it did not intend to release further public updates until there was meaningful new science to share.

The FDA never ordered a recall of grain-free foods over DCM and never told owners to stop feeding them. It did ask veterinarians to report suspected cases.

What is still uncertain

Researchers have looked at several possible explanations, including how certain ingredients affect taurine (an amino acid important for heart function) and other nutrients, and whether some formulations differ in ways that matter. Some affected dogs had low taurine levels and others did not. Studies have reached different conclusions, and as of October 2026 there is no settled scientific answer.

What the evidence does support:

• “Grain-free” is a marketing category, not a health category. Most dogs do not need a grain-free diet.
• True grain allergies in dogs are uncommon; when food allergies occur, they are more often linked to proteins. Your vet can guide a proper elimination diet if allergies are suspected.
• Many veterinarians and veterinary cardiologists suggest caution with diets where legumes or potatoes are main ingredients, especially for breeds at risk of DCM.

Signs of heart problems to watch for

According to the FDA, owners should contact a veterinarian as soon as possible if a dog shows possible signs of DCM or other heart disease, including:

• decreased energy or tiring easily on walks;
• coughing;
• difficulty breathing or fast breathing at rest;
• episodes of collapse or fainting.

Seek emergency care right away if your dog collapses, has labored breathing, blue or gray gums, or cannot settle because of breathing trouble. Our guide to signs your dog is sick covers other warning signs.

Only a veterinarian can diagnose DCM, usually with an exam and tests such as an echocardiogram (heart ultrasound). Do not try to treat suspected heart disease with diet changes or supplements on your own.

What to do if your dog eats a grain-free diet

1. Don’t panic or switch overnight. A sudden change can cause stomach upset.
2. Write down exactly what your dog eats, including treats, toppers and chews, and bring it to your next vet visit. The FDA specifically asks owners to share the full diet with their veterinarian.
3. Ask your vet whether your dog’s breed, age and health make a change worthwhile, and whether any screening makes sense.
4. If you change food, do it gradually over about a week. See how to switch dog food.
5. Check the label. Look for a complete and balanced statement for your dog’s life stage. Our guide on reading a pet food label explains the ingredient list and naming rules.

If your vet suggests a diet change for a dog already diagnosed with heart disease, they may consult a board-certified veterinary nutritionist or cardiologist. Follow their plan rather than general internet advice.

How to report a suspected case

If your veterinarian diagnoses DCM and you or they suspect a link to diet, you can report it to the FDA through its pet food complaint process. Keep the food packaging (including lot number and best-by date) and your dog’s records.

Grain-inclusive vs grain-free: what to consider

Bottom line

The FDA found an association worth investigating but did not prove that grain-free diets cause DCM. Most dogs do not need grain-free food. If your dog eats one, talk to your veterinarian about whether to change, watch for signs of heart disease, and switch gradually if you do.

FAQ

Did the FDA ban grain-free dog food?

No. The FDA investigated reports and published updates, but it did not ban or recall grain-free foods because of DCM.

Can a taurine supplement prevent DCM?

Do not give supplements without your vet’s advice. Taurine is one factor researchers studied, but DCM is complex and some affected dogs had normal taurine levels.

Is DCM reversible?

Some dogs whose DCM was suspected to be diet-associated improved after diet changes and treatment, but outcomes vary. Only your veterinarian can assess your dog.

Are cats affected?

The FDA investigation focused on dogs. If you have concerns about your cat’s heart or diet, ask your vet.