Grain-free dog food is widely available, and since 2018 it has also been linked in the news with a heart condition called dilated cardiomyopathy (DCM). This guide explains what “grain-free” means, what the US Food and Drug Administration (FDA) actually said about its investigation and what it didn’t, and why changes to your dog’s diet are best discussed with your vet.
What grain-free means
“Grain-free” is a marketing description, not one of the legal labelling categories such as “complete” or “complementary”. It means the recipe doesn’t contain grains. When the FDA classified foods in its investigation, it counted a product as grain-free if it didn’t contain corn, soy, wheat, rice, barley or other grains (FDA investigation page). A grain-free food still has to be labelled complete or complementary, with a composition list and analytical constituents like any other dog food. See our guide to reading a dog food label.
Why some owners choose grain-free
Owners choose grain-free foods for different reasons. Some believe grains are “fillers”, some suspect their dog reacts to grains, and some simply prefer the recipe or the brand. We describe these reasons here without endorsing them.
On the “filler” point, the World Small Animal Veterinary Association (WSAVA) says that nothing in a pet food is truly a filler, and that every ingredient must have a nutritional purpose. It explains that cereal grains mostly provide energy but also provide essential nutrients and fibre, and that dogs can digest properly cooked grains. It adds that there is no evidence to show grains are harmful, as long as the overall diet is complete and balanced (WSAVA FAQs and myths).
The FDA investigation into diet and canine DCM
DCM is a disease of a dog’s heart muscle that results in an enlarged heart. Historically, it has been linked mainly to a genetic predisposition in certain breeds. Here is what the FDA has said, in its own words where possible, with dates:
- July 2018: the FDA announced it had begun investigating reports of DCM in dogs eating certain pet foods, many labelled “grain-free”, which contained a high proportion of peas, lentils, other legume seeds (pulses) and/or potatoes as main ingredients.
- June 2019: in its third status report, the FDA said the potential association between diet and DCM “is a complex scientific issue that may involve multiple factors”.
- December 2022: the FDA said it did not intend to release further public updates “until there is meaningful new scientific information to share”. It noted that adverse event numbers, by themselves, “do not supply sufficient data to establish a causal relationship with reported product(s)”.
- The FDA’s questions and answers (page current as of August 2024) say that most diets in the reports had legumes and pulses high in their ingredient lists, and that these included both grain-free and grain-containing formulations. The FDA says legumes and pulses have been used in pet foods for many years, “with no evidence to indicate they are inherently dangerous”. It also says it “does not know the specific connection between these diets and cases of non-hereditary DCM” (FDA Q&A on non-hereditary DCM).
- Recalls: the FDA says it “has no definitive information indicating that the diets are inherently unsafe and need to be removed from the market”.
In short, the FDA has not said that grain-free food causes DCM. It has said there is a potential association that is complex, may involve multiple factors such as genetics, underlying medical conditions and diet, and isn’t yet understood. Throughout, the FDA has encouraged pet owners to work with their vets, who may consult a board-certified veterinary nutritionist, before making diet changes.
If your dog shows possible signs of heart disease, the FDA lists decreased energy, cough, difficulty breathing and episodes of collapse as examples. Contact your vet as soon as possible.
Allergies and sensitivities
Some owners choose grain-free because they think their dog has a food allergy. Diagnosing a food allergy or intolerance is a job for your vet, not something to settle by switching foods at home. WSAVA notes that the ingredient list may be useful when choosing a food for a dog with a diagnosed food allergy or intolerance. It warns, though, that cross-contamination with ingredients not listed on the label can happen during normal manufacturing. If you’re concerned about how your dog reacts to food, speak to your vet before changing their diet.
Choosing a complete food, with or without grains
Whether a food contains grains matters less than the basics:
- Is it labelled complete?
- Is it intended for your dog’s life stage?
- Can you follow the feeding guide and keep your dog at a healthy weight?
- Does your vet have any advice for your individual dog?
WSAVA publishes a checklist for selecting a pet food that you can take to your vet.
FAQ
Is grain-free dog food bad?
The FDA has not concluded that it is. It is investigating a potential, complex association between certain diets, many of them grain-free and high in pulses, and non-hereditary DCM, and it has said it doesn’t know the specific connection. Talk to your vet before changing your dog’s diet.
Does grain-free food cause DCM?
This hasn’t been established. The FDA says report numbers alone can’t establish a causal relationship, and that reports have involved both grain-free and grain-containing diets.
Does my dog need grain-free food?
Most dogs don’t need a particular grain status. WSAVA says that dogs can digest properly cooked grains and that there’s no evidence they’re harmful in a complete and balanced diet. If you think your dog has a food allergy, ask your vet.
Grain-free vs grain-inclusive: which should I choose?
Start with a complete food for your dog’s life stage, whichever type it is, and discuss any concerns, including DCM, with your vet.
Sources
Checked on 22 October 2026. This guide summarises official statements and isn’t veterinary advice.
- US Food and Drug Administration, FDA investigation into potential link between certain diets and canine dilated cardiomyopathy (updates 2018 to December 2022).
- US Food and Drug Administration, Questions and answers: FDA’s work on potential causes of non-hereditary DCM in dogs (current as of 19 August 2024).
- WSAVA, Global Nutrition Guidelines, FAQs and myths and Selecting a pet food.