Dogs, just like people, can have debilitating food allergies. Wheat, contains gluten, which can cause problems for people and their pets. Corn is not easily digested by dogs, nor is it particularly nutritious. Corn is used as a filler in most dog food products. Some people choose Foxy Treats because they, not their dogs, suffer from food allergies or Celiac disease. Soy is not necessarily bad for dogs, but feeding your dog soy can result in severe skin allergies, such as excessive itching.