I must have been replying to someone whose dog sounded like it had an intolerance issue and mentioned that the dog was on Purina at some point, but I wasn’t sure if it still was. Almost all Purina foods are chicken and grain, so that would be the most likely things for the dog to develop an intolerance to. Earthborn Holistic Great Plains Feast would be a good one for you to try. Beef is a common allergy too, BTW. Look for something that has different protein and starch from what he was itching on. When you find a food that works for him, give him some time to get over ALL symptoms, then start adding single ingredients to his food to see if he starts reacting to them.
