My old guy has kidney failure and Cushings Disease and has always been sensitive to certain food items in dry kibble. He does well on 80/20 boiled ground beef and either white rice (I process it into smaller grains before cooking it) or malt-o-meal cereal. I know it sounds weird but it's low phosphorus for kidney disease and is easy to digest. He actually does better on the ground beef than chicken. He also gets digestive enzymes with every meal, a vitamin/mineral tab, fish oil and a calcium supplement.