Corn (Ground Whole Grain Corn) in dog and cat food

Is it OK for dogs and cats?

Dogs

Corn in a complete dog food is not a known health problem for most dogs. They digest its cooked starch well, and corn is reported as an allergy trigger less often than beef, dairy, chicken or wheat. The main safety issue is aflatoxin contamination of corn, and FDA treats dog food above 20 ppb aflatoxin as adulterated.

Cats

Cats are carnivores whose natural diet is low in carbohydrate, yet in a feeding study they digested cooked corn starch in kibble well. In that study the corn diet raised blood glucose more than most other starch sources tested, though the authors concluded that starch affects blood glucose less in cats than in dogs. Corn allergy is reported in cats but uncommonly, and the same 20 ppb aflatoxin action level applies to cat food.

How settled this is: A popular concern the sources do not support

What corn (ground whole grain corn) is

Corn (maize, Zea mays) grain that has been ground. The EU Catalogue of feed materials defines maize simply as the grains of Zea mays, and says "maize" may also be called "corn". Other corn products are separate fractions of the kernel, each with its own name and description. Examples are corn gluten (maize protein), corn bran, corn germ meal and corn grits.

Why it is in pet food

AAFCO's consumer guide says plant ingredients such as corn supply calories and nutrients and help kibble hold together. Ingredient lists run from most to least by weight. In FDA's 2021 sample of pet foods that contained corn, corn was the first grain listed in 65% of the dog foods and 73% of the cat foods. In research diets, corn has been used as the main starch source in extruded (kibble) foods for dogs and cats.

What it does in the food

Mainly a source of starch for energy. Dogs: a study of 36 dogs compared six starch sources in extruded diets. Starch digestibility was above 98% for every diet, including corn. The corn diet's dry matter and energy digestibility was lower than the brewer's rice and cassava diets but higher than the pea and lentil diets. In the first 30 minutes after eating, the corn, brewer's rice and cassava diets raised blood glucose and insulin more than the other diets. Cats: a study of 36 cats compared the same six starch sources in extruded diets with 35% starch. Starch digestibility was above 93% for all of them. The corn diet gave higher average and peak blood glucose than the cassava, sorghum, lentil and pea diets, and it was the only diet that raised glucose above baseline (at 4 and 10 hours after the meal). The authors suggest that starch affects blood glucose and insulin less in cats than in dogs and people.

Safety and limits

Aflatoxins: FDA has set an action level of 20 ppb for aflatoxins in dog and cat foods, and foods above it are considered adulterated. In 2020 and 2021, pet foods with unsafe aflatoxin levels, some above 500 ppb, led to hundreds of pet illnesses and deaths. FDA traced the aflatoxin in each recalled food to the corn it contained. FDA's 2021 survey tested 200 dog and cat foods containing corn or corn by-products, all but one of them dry kibble. None exceeded 20 ppb. Eight samples had low levels, under 7 ppb. FDA says aflatoxin below the action level has not been associated with illness in dogs and cats. FDA also says aflatoxin levels vary with growing-season weather and corn storage, and it recommends that makers monitor the corn they use. Signs of aflatoxin poisoning in dogs and cats include loss of appetite, lethargy and jaundice. Allergy: a 2016 review of published cases of food allergy found corn reported as a trigger in 13 of 297 dogs (4%) and 3 of 78 cats (4%). In dogs, beef, dairy, chicken and wheat were reported more often. In cats, beef and fish were reported most often.

What depends on the amount and the recipe

Grain quality and storage, because aflatoxin risk varies with weather and storage. Proper cooking into kibble matters, since the digestibility results are for extruded diets. Other factors are how much of the recipe it makes up and the individual animal, because a small share of dogs and cats with food allergy react to corn.

Not the same as

• Corn gluten meal / corn protein meal — The protein fraction separated from corn during starch manufacture, not the whole grain.
• Corn bran — Mainly the outer skins of the kernel, left over from making corn flour or semolina.
• Corn germ meal — Made from corn germ after its oil has been extracted.
• Corn grits — The hard, flinty parts of ground corn, with little or no bran or germ.

Sources

1. What's in the Ingredients List? — Association of American Feed Control Officials (AAFCO). Plant ingredients such as corn supply calories and nutrients and help kibble hold together. Ingredients are listed from most to least by weight.
2. Commission Regulation (EU) 2022/1104 amending Regulation (EU) No 68/2013 on the Catalogue of feed materials (Part C, entries 1.2.1 Maize, 1.2.4 Maize bran, 1.2.8 Maize protein, 1.2.12 Maize germ meal, 1.2.18 Maize grits) — European Union, Official Journal L 177 (Publications Office), 2022. Maize is the grains of Zea mays, and 'maize' may be called 'corn'. Descriptions of the separate maize fractions are used in notTheSameAs.
3. FDA Report of FY 21 Special Sampling Assignment for Aflatoxins: Kibbled Dog & Cat Food — U.S. Food and Drug Administration, Center for Veterinary Medicine, 2022. 20 ppb action level, the 2020-2021 recalls traced to corn, and 2021 survey results: 200 foods (1 wet), none above 20 ppb, corn the first grain listed in 65% of dog and 73% of cat samples. Aflatoxin below the action level is not associated with illness. Signs of aflatoxicosis, and variability with weather and storage.
4. 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 12:9 — BMC Veterinary Research (via PubMed Central), 2016. Corn was reported as a food allergen in 13 of 297 dogs (4%) and 3 of 78 cats (4%). Beef, dairy, chicken and wheat were more common in dogs, and beef and fish were most common in cats.
5. Carciofi AC et al. Effects of six carbohydrate sources on dog diet digestibility and post-prandial glucose and insulin response. J Anim Physiol Anim Nutr 92(3):326-336 (PubMed abstract) — U.S. National Library of Medicine (PubMed), 2008. In dogs, starch digestibility was above 98% for all diets including corn. Corn ranked between rice/cassava and peas/lentils for dry matter digestibility and gave a higher early glucose and insulin response.
6. de-Oliveira LD et al. Effects of six carbohydrate sources on diet digestibility and postprandial glucose and insulin responses in cats. J Anim Sci 86(9):2237-2246 (PubMed abstract) — U.S. National Library of Medicine (PubMed), 2008. In cats, starch digestibility was above 93% for all diets including corn, and cats digest starch efficiently when it is properly processed into kibble. The corn diet gave a higher glucose response, and starch affects glucose less in cats than in dogs and humans.

Checked against these sources on 2026-10-15. Definitions are in our own words. This is a reading aid, not veterinary advice: a vet who knows your animal comes first.