Corn

Known risk factors for diabetes in cats are excess weight, inactivity, older age and being male. How much dry, high-carbohydrate foods add to this risk is still debated.

Corn is a cereal grain used in dry cat food in several forms, such as ground corn, corn meal and corn gluten meal. Tufts veterinary nutritionists report that the starch in corn was 90 to 99 percent digestible in studies and that corn is rarely confirmed as the cause of allergies in dogs or cats. For a cat with a medical condition, ask your veterinarian about its diet.

Source: sites.tufts.edu

Corn supplies starch for energy and helps dry kibble hold its shape. Tufts veterinary nutritionists add that corn provides linoleic acid, several B vitamins and carotenoids. Pettings scores corn 1 out of 5 because cats have no dietary need for carbohydrate and corn is a low-cost starch that can take the place of meat and fat in a recipe.

Source: sites.tufts.edu

Tufts veterinary nutritionists say no. They write that grains and other carbohydrates in pet food are not there as fillers, since they provide energy and other nutrients. A true filler would add bulk with no nutritional value. Pettings scores corn low for a different reason: as a starch, it takes space that meat and fat could fill in a carnivore's diet.

Source: sites.tufts.edu

Aflatoxin is a toxin made by the mold Aspergillus flavus. FDA says the mold can grow on corn and other grains used in pet food, and the toxin can be present even when no mold is visible. At high levels it can cause liver damage and death in pets, and FDA has announced pet food recalls over it. If your cat ate a recalled food, call your veterinarian.

Source: fda.gov

Pettings scores corn 1 out of 5 and files it as a general cat food ingredient. We found it on 58 of the 149 dry cat foods in our list. The ingredient score is separate from a food's overall score, which you can see on each food's page.