A lot of animals have food allergies. Dogs and cats need to be fed a good food that has meat listed as the first ingredient and one that doesn't have bi-products. I have a pure bred dog that has severe allergies, which without the right food, would cause her to lose her fur. I feed her Blue Buffalo dog food. Yes, you pay more, but its worth it. Also, if using a cheap food, the pet does not absorb what they need from the food. A cheap pet food is like candy for a child.... there is no benefit. With a better food, the dog will eat less than with a cheaper and they absorb more from the food and they get hungry less often.... I know this is true because I tried this on my dog that doesn't have allergies.