Purina pro plan sterilised cat optirenal rich in turkey is a dry kibble that has been adapted to suit the nutritional needs of neutered cats after a cat is neutered its metabolism changes lowering its energy needs whilst increasing its appetite pro plan sterilised cat food has a high protein content and is lower fat neutering your cat also increases its risk of urinary tract infections flutd but this food has been designed to help to prevent urinary stones from forming this balanced d