UTIs are more common in cats which eat canned food containing fish. A good vet will tell this to the owners, but many realize that they will have repeat customers if the cats continue eating the fish based foods. All cat lovers need to keep fish based foods away from their cats, and seek vet care at the first sign of unusual stool or bladder habits. Kitties have a difficult way of communicating, this is one way they have of saying "I hurt".