My Diezel has very serious food allergies. He is also allergic to several tyoes of grass and trees. How do i know?? I finally had an allergy test done on him because he was always breaking out, scratching himself raw and had all these hotspots all over him. THey gave me the list of things he was allergic to including all the foods, which were almost any and every ingredient they put in the dog foods. Your Ozzie could very well be allergic to pollen, grass, or whatever, these dogs do love to eat grass, at least everyone i have owned. The allergy test is kind of expensive, but for me it was worth it, because i was going thru all kinds of different foods trying to figure out what he was allergic to. THey also gave me a list of foods he could eat, so that helped too. He still breaks out, but if he gets too bad, we go to the vet and get some prednisone steroid for him and he is all better in a day or two. Benadryl is not strong enuf for his allergies. Hope this helps u out