Why won't my dog stop itching?

We had the same problem- definitely a food allergy. I would recommend the Wellness brand sweet potato and fish. Stay away from wheat and corn based products and stay away from beef and chicken. We feed our dog mostly fish, sweet potato, or duck and it seems to help. Also we bath him every other week. And lastly, don't let anyone give him "treats" that aren't approved first. It will take a couple week for the allergen to leave his body.