For the Nutritional Management of Pets Recovering From Serious Illness, Accidents and Surgery. Both dogs and cats can undergo significant changes when faced with a serious illness, injury or surgery. They may have trouble maintaining natural defenses and sparing lean body mass (in other words, they may be losing body weight from muscle or organ tissue), which can affect recovery. Prescription Diet® a/d® Canine/Feline pet food has been specifically formulated by veterinarians to be fed to dogs or cats in these situations. These conditions can be helped by adding the key nutrients and digestible energy found in Prescription Diet a/d. The nutritional formulation of Prescription Diet a/d may also be useful for pets with a variety of conditions.