If you come across your dog itching after the provision of specific food materials, then suspect the food allergy in this animal. However, conditions like fungal infections need to be ruled out in general before the conclusion of itching as a sign of food allergy.
There are many recorded incidences of allergies of dogs to corn or to wheat. However, the food allergies vary from dog to dog. Read the labels clearly before feeding your dogs with pet food materials, in such occasions. Too much colored food materials may be avoided since they may cause allergies to your dog.