[capt_noonie]

You may have to do allergy testing from the vet then. It's an extensive test and probably costly also. Then you may find out that she is allergic to grass or dust, something you cannot do anything about. Or perhaps you should talk to a dog nutritionist and see if you can start home cooking. There is a brand called Honest Kitchen. All their food is dehydrated/freeze dried (can't remember which). They have one line of food that is just veggies that you add in your own protein. That worked for us for a while, but it does take some time to prep the food, and the dogs loved it so much that they would bark non stop until it was ready.