Grain-free food became popular on the idea that grains are unnatural or cause allergies. The evidence is more complicated, and one concern points the other way.
The heart disease question
On 12 July 2018 the US Food and Drug Administration (FDA) said it was investigating reports of dilated cardiomyopathy (DCM), a disease of the heart muscle, in dogs eating foods with peas, lentils, other legume seeds or potatoes as main ingredients. It noted these ingredients seemed more common in foods labelled “grain-free”.[2] The FDA counted an ingredient as “main” if it appeared in the first ten, before vitamins and minerals.[1]
In its June 2019 update, the FDA reported that more than 90% of the products named in reports were grain-free, and 93% contained peas and/or lentils. Most reports involved dry food, though raw, semi-moist and wet foods also appeared.[1]
The FDA has been clear that these reports alone don’t establish that the foods caused the disease, and called it a complex issue that may involve multiple factors. In December 2022 it said it wouldn’t publish further updates until there was meaningful new scientific information.[1]
Veterinary cardiologists and nutritionists writing in 2018 described the foods under suspicion as “BEG” diets (boutique brands, exotic ingredients, or grain-free) rather than grain-free alone.[3][4]
Are grains a common allergy?
Not especially. A 2016 review of published studies covering 297 dogs with food allergies found the most commonly reported culprits were beef (34%), dairy (17%), chicken (15%) and wheat (13%). Corn (4%) and rice (2%) were uncommon.[5] A dog can be allergic to a grain, but meat proteins were reported more often.
What this means when choosing a food
- Grain-free isn’t automatically better. Look at what replaces the grain: peas, lentils and potato high in the list were the pattern the FDA looked at.
- If your dog has a diagnosed allergy, avoid the specific ingredient your vet identifies, whether that’s a grain or a meat.
- Our score doesn’t reward grain-free for its own sake. For dry food it looks at how much of the recipe is grain, because a high grain share usually means less meat. Peas and lentils don’t lose points, but you can see where they sit in every food’s ingredient list.
Want to avoid grain anyway? The grain-free list and the “Avoid” filter in the directory check the full ingredient list.
Sources
- FDA Investigation into Potential Link between Certain Diets and Canine Dilated Cardiomyopathy, US Food and Drug Administration
- FDA Investigating Potential Connection Between Diet and Cases of Canine Heart Disease (12 July 2018, archived), US Food and Drug Administration
- Freeman LM, Stern JA, Fries R, Adin DB, Rush JE. Diet-associated dilated cardiomyopathy in dogs: what do we know? JAVMA 2018;253(11):1390–1394, Europe PMC
- It’s Not Just Grain-Free: An Update on Diet-Associated Dilated Cardiomyopathy, Petfoodology, Cummings School of Veterinary Medicine, Tufts University
- Mueller RS, Olivry T, Prélaud P. Critically appraised topic on adverse food reactions of companion animals (2): common food allergen sources in dogs and cats. BMC Veterinary Research 2016;12:9, Europe PMC
This guide is general information, not veterinary advice. Spotted an error? Tell us.