Dog food types
Is grain free dog food bad for dogs?
Last updated 23 September 2026 · How we write and check this
Short answer
Grain free food is not automatically bad, but the US FDA has investigated a possible link between certain grain free diets, particularly those high in legumes like peas and lentils, and a heart condition called dilated cardiomyopathy in dogs not otherwise genetically predisposed to it. The investigation remains ongoing and no single ingredient has been proven to cause the condition.
What the investigation actually found
Between 2018 and the following years, the FDA collected reports of dilated cardiomyopathy in dogs eating certain grain free diets heavy in peas, lentils, or other legumes as primary ingredients, but a direct causal mechanism has not been confirmed, and many dogs eating these diets show no heart problems at all.
Why grain free became popular in the first place
Grain free formulas were marketed around the idea that grains cause allergies or are less digestible for dogs, though true grain allergies are actually uncommon, and dogs generally digest properly cooked grains well.
What a cautious approach looks like
If you choose a grain free food, look for one where a named meat, not a legume, is the first ingredient, and discuss any unexplained lethargy, coughing, or exercise intolerance with your vet, since these can be early signs of heart changes.
Key takeaways
- A possible but unproven link exists between certain grain free diets high in legumes and dilated cardiomyopathy.
- Most dogs eating grain free food show no heart problems, and the investigation remains ongoing.
- Choosing a formula where named meat, not legumes, leads the ingredient list is a reasonable precaution.