Pet food allergies, is there such a thing? You bet. The big three allergens for dogs and cats are corn, wheat and soybeans. Did you notice they are all grains? Some pets will do fine on the big three and others will not. Several symptoms of food allergies include chewing on paws, hair loss and rashes, constant licking and scratching with no indication of insects. If your critter(s) are having issues you can have them tested for allergies. Some vets do allergy testing and there are several home test kits available. Before you jump into allergy testing, here are some things to think about.