Whole Grain Corn

Corn supplies starch for energy, some protein and linoleic acid, an omega-6 fat. Once cooked and ground, dogs and cats digest it well. It’s often described as a filler, but it does supply nutrients, and it’s far from the top of the list of allergens: about 4% of dogs and cats with food reactions in one review.

Its protein is low in lysine and tryptophan, so it has to be balanced by other ingredients. A food with several corn ingredients listed separately may contain more corn than any one position suggests.