Have you ruled out environmental allergies? Grass/pollen, lawn sprays, household cleaners, etc.....
Four weeks might not be enough time for her respond to a food change. The allergens can take 6-8(+) weeks to work themselves out of her system. You want to give it at least two months before deciding a food isn't going to work....
A lot of people forget to check treat ingredients. Many of the popular brands found in pet stores contain wheat, corn, soy, etc. Be sure her treats don't contain anything like that either. |