Are grains bad for dogs and cats?

The short answer

Grain-free can make a bag of pet food sound reassuring before you’ve even turned it around. The phrase feels like a recommendation. All it actually tells you is that the recipe leaves out grains.

Properly cooked grains can be useful ingredients in dog and cat food. They can provide energy, fiber, vitamins, minerals, and fatty acids. Whether a food is a good choice depends on the whole recipe, how it’s made, and the animal eating it.^4,2

The grain claim on the front of the bag can’t tell you whether the food provides all the nutrients your pet needs. It also can’t tell you who developed the recipe, how carefully the company tests each batch, or how well the food will suit your particular dog or cat.^1,5

What grains do in pet food

Corn, rice, oats, barley, and wheat are often grouped together in pet food conversations, even though they’re different ingredients. In a prepared food, grains may provide starch for energy along with fiber and other nutrients. Starch also helps dry kibble hold its shape.^4,2

You’ll sometimes hear these ingredients dismissed as fillers. That word skips over what the ingredient is doing in the recipe. The World Small Animal Veterinary Association says dogs and cats can digest properly cooked cereal grains when the full diet is complete and balanced. The rest of the recipe still matters, including how much of each ingredient is used and how the food is processed.⁴

Cats need a little extra explanation here. They’re obligate carnivores, which means they rely on certain nutrients found in animal products. Some commercial cat foods also contain grains and other plant ingredients. A cat food still has to provide the animal-based nutrients and overall balance a cat needs.^8,1

Start with the small print

If a food is meant to be your pet’s main diet, look for the nutritional adequacy statement. In the United States, a dog or cat food labeled complete and balanced must meet an AAFCO nutrient profile or pass a feeding trial that follows AAFCO procedures. The statement should also say which species and life stage the food is made for.¹

This statement gives you a useful starting point. It tells you that the food is meant to supply a full diet for the species and life stage on the label. You’ll need more information to decide how well the food is made or whether it suits your pet.

The ingredient list can help you see what’s included and avoid something your pet has a known reaction to. Ingredients appear in order by weight when the recipe is made. That order can’t show how easy the finished food is to digest, how much of each nutrient your pet’s body can use, or how carefully the company checks its products.^3,4

The guaranteed analysis has limits, too. It lists a few minimums and maximums, such as minimum crude protein and maximum moisture. That gives you only a small slice of the food’s overall nutrition.³

PetRoot’s food scores also consider the form and prominence of carbohydrate ingredients. A complete food that relies heavily on isolated starch can receive a small, limited deduction, while a grain-free claim earns no points on its own. We keep that effect modest because an ingredient list can’t show how well the finished food performs.

Ask about the food behind the label

Some of the most useful information has to come from the company. WSAVA suggests looking at who developed the recipe, what nutrition training that person has, and how the company checks both its ingredients and its finished foods. Those checks may include nutrient analysis, testing for bacteria and toxins, and making sure the food and packaging hold up through the stated shelf life.⁵

That may sound like homework, but a pet food company should be able to answer basic questions about how it makes and tests its food. If the answers are vague, the front of the bag won’t fill in the gaps.⁵

Quality controls also matter because ingredients grown in fields can pick up mold and other contaminants. For example, the FDA says toxins made by certain molds can occur on grains, seeds, and complete animal foods. Many common production steps don’t destroy these toxins, so sourcing, storage, testing, and prevention all matter. Finding grain on an ingredient list doesn’t show that a food is contaminated. Grain-free foods need careful controls too.⁷

Why DCM made grain-free food more complicated

Grain-free diets drew much more attention after the FDA began investigating reports of non-hereditary dilated cardiomyopathy, or DCM, in dogs. DCM is a disease that weakens the heart muscle and makes it harder for the heart to pump blood.⁶

The story was often shortened to a simple claim that grain-free diets cause DCM. The FDA’s findings are still unsettled. The agency received reports involving grain-free and grain-containing foods. Many of the reported diets listed peas, lentils, or other pulse ingredients high on the label, though the FDA says there’s no evidence that pulses are inherently dangerous. Researchers are still looking at the full recipe, processing, nutrient availability, genetics, underlying health conditions, and other possible factors.⁶

These reports can only tell us so much. Pet owners and veterinarians submitted them voluntarily, some diagnoses couldn’t be verified, and no one knows how common non-hereditary DCM would normally be in the wider dog population. The FDA hasn’t concluded that the reported foods are inherently unsafe or asked for them to be removed from the market on that basis.⁶

For pet owners, the grain-free wording doesn’t settle the heart question. If your dog has DCM, is being evaluated for heart disease, or needs a diet change for a medical reason, talk with your veterinarian. The FDA investigation discussed here concerns dogs, so it can’t answer the same question for cats.⁶

When grains really can be a problem

Some pets do react to particular grains. In a review of dogs with diagnosed skin-related food reactions, wheat was among the more commonly reported allergens. Beef, dairy, and chicken also appeared frequently. For cats in the review, beef, fish, and chicken were the most commonly reported sources. These findings came from pets with diagnosed reactions in a collection of older, varied studies. They don’t tell us how common each allergy is among all dogs and cats.⁹

A few gluten-sensitive conditions are also tied to particular breeds. Researchers have documented an inherited intestinal disorder in Irish Setters and a gluten-sensitive movement disorder in Border Terriers. A veterinarian would need to diagnose either condition.^10,11

If you think your pet is reacting to a food, talk with your veterinarian before cycling through bags. A veterinarian may suggest feeding a carefully chosen diet for a set period and then reintroducing ingredients to see whether symptoms return. That process gives you a clearer answer than changing several ingredients at once. An ingredient list can help you avoid a known trigger, although cross-contact during manufacturing is still possible.^9,4

PetRoot can keep track of the ingredients you care about. Add your pet’s allergies or sensitivities to their profile, and Pet Fit can check reviewed formulas for matches. You can also ask it to flag personal preferences, such as grains, peas, or explicit starch ingredients. When there’s a clear match, a saved allergy can lead to an Avoid result. A sensitivity or preference brings up Questionable fit, so the result reflects why you wanted the ingredient flagged.

Five things worth checking

When you’re comparing foods, start here:

• Species and life stage: Is the food complete and balanced for your dog or cat’s current life stage?¹
• Your pet’s needs: Does your pet have a diagnosed condition, known food reaction, or veterinary diet that affects the choice?
• The person behind the recipe: Who developed the food, and what nutrition training do they have?⁵
• Testing: How does the company check its ingredients and finished products, and will it share useful details?⁵
• How your pet is doing: What do your pet’s weight, digestion, skin, coat, energy, and veterinary checkups tell you over time?

You don’t have to decide whether every grain is good or bad. The adequacy statement, the company’s expertise and testing, and your pet’s individual needs will tell you much more about a food. Those details take a little longer to check than a grain-free badge, but they’re worth the extra turn of the bag.^1,5