Grain-free dog food and DCM: what the FDA found

In 2018 the US Food and Drug Administration began investigating reports of dilated cardiomyopathy (DCM), a disease of the heart muscle, in dogs eating certain diets. Many of those diets were labelled grain-free and contained high proportions of peas, lentils, other legumes or potatoes. The FDA did not prove that these diets cause DCM. In December 2022 it said it would not release further updates until there was meaningful new scientific information.

The question is still open. This guide explains what is known, what isn’t, and how to talk about it with your vet.

What DCM is

Dilated cardiomyopathy is a condition in which the heart muscle weakens and the heart enlarges, so it pumps less effectively. It can lead to heart failure.

Some breeds have a known inherited tendency to DCM, including Doberman Pinschers, Great Danes and Irish Wolfhounds. What caught vets’ attention from around 2018 was a rise in reported DCM cases in dogs of breeds not usually associated with the disease.

What the FDA did

In July 2018 the FDA announced it was looking into reports of DCM in dogs eating certain pet foods. The foods in many of the reports were labelled grain-free and listed peas, lentils, other legume seeds (pulses) or potatoes high in their ingredient lists.

In June 2019 the FDA published a further update, which included the brands most frequently named in the reports it had received. The FDA was clear that being named in reports did not mean a brand’s food had been shown to cause DCM, and it did not ask any company to recall products on this basis.

Over the following years the FDA worked with veterinary cardiologists, nutritionists and researchers to study possible factors, including diet ingredients, nutrient levels and genetics.

What the FDA said in December 2022

In its December 2022 update, the FDA said that the reports it had received did not on their own establish that the diets caused DCM, and that DCM is a complex condition that may involve several factors. It said it did not intend to release further public updates until there was meaningful new scientific information, and that it would keep working with researchers.

That December 2022 update is the most recent one we found when writing this guide. We’ll update this guide if the FDA publishes new findings. Read the FDA’s investigation page for the full text.

What is known and what isn’t

Known:

• DCM cases were reported in dogs eating a range of diets, many of them grain-free with high levels of pulses or potatoes.
• Some dogs in the reports improved after a change of diet, often alongside medical treatment. Those reports came from vets, not controlled trials.
• DCM has more than one cause, including genetics.

Not known:

• Whether a specific ingredient, a combination of ingredients, a nutrient level or something about how the foods are made is involved.
• Whether “grain-free” itself matters, or whether it’s a marker for other features these recipes tend to share.
• How many dogs eating these diets are affected. Reports to the FDA are voluntary and can’t tell us how common something is.

“Grain-free” is a marketing term, not a nutrient profile

A grain-free food leaves out wheat, corn, rice, barley, oats and other cereal grains. To replace their energy and structure, recipes often use peas, lentils, chickpeas, potatoes or sweet potatoes. That’s why the FDA’s attention was on legumes and potatoes rather than on the absence of grain as such.

Grains are not a common cause of allergy in dogs compared with animal proteins such as beef, dairy and chicken. Some dogs do need to avoid a specific grain, usually wheat, but that’s a different decision from choosing grain-free across the board.

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

There’s no need to panic, and no single answer that fits every dog. These are reasonable steps:

1. Talk to your vet about your dog’s breed, age, diet and any signs such as tiring easily, coughing, fainting or breathing faster than usual at rest. If DCM is suspected, your vet may refer you to a veterinary cardiologist.
2. Look at the ingredient list. Note where peas, lentils, other legumes and potatoes appear, and whether several of them appear high in the list together.
3. Check the AAFCO statement and the manufacturer. The WSAVA’s nutrition guidelines suggest asking manufacturers who formulates their diets, whether they employ a qualified nutritionist, and what quality control they use.
4. Don’t switch abruptly unless your vet tells you to. Change foods gradually over a week or so to avoid stomach upset.

Questions to ask your vet

A short list helps you get the most out of the appointment:

• Does my dog’s breed have a known risk of DCM?
• Based on my dog’s age and health, would you recommend heart screening, such as an echocardiogram?
• Is there anything about my dog’s current food you’d like me to change, and why?
• If we change foods, which features should the new food have?
• Should my dog’s taurine levels be checked?

Bring the bag, or a photo of the ingredient list and AAFCO statement. It saves time and avoids guessing.

Why the reports can’t settle the question

Reports to the FDA come from owners and vets who choose to submit them. They are useful for spotting a pattern worth investigating. They can’t show how often a problem happens, because nobody counts the dogs eating the same foods who stayed healthy. They also can’t separate the effect of a diet from the effect of breed, age or other health conditions.

Answering the question properly needs controlled studies that compare groups of dogs on different diets over time. Some research of this kind has been published since 2018, and the results have not produced a simple answer that applies to every grain-free food.

How we handle it on Right Dog Food

We don’t label any food “safe” or “unsafe”. In our database you can filter by grain-free or grain-inclusive, and our Label Checker shows where legumes and potatoes appear in an ingredient list. The Food Finder can exclude peas and legumes if you and your vet decide to avoid them.

For help reading the rest of the label, see how to read a dog food label.