My 6 yoa 122lb Rottweiler tested allergic to 33 different items including chicken, turkey, lamb, soybean, rice, egg, milk, all berries, all squash, pumpkin, sunflower (and oil) and guar. He suffers from irritable bowel, hip dysplasia and arthritis. He is overweight and doesn’t like any fish based foods. Does anyone have a suggestion for feeding? If I have to prepare his food I am willing but want to be sure I meet all his dietary needs.