Hill’s Prescription Diet a/d Canine help in diet and body recovery as cats and dogs undergo significant metabolic changes when recovering from surgery, illness or injury. For the nutritional support of pets recovering from serious illness, accident and surgery Cats and dogs can undergo significant metabolic changes when recovering from a serious illness, injury or surgery. During these stressful conditions the body is challenged to maintain strong natural and spare lean body mass, which makes it is even more important to feed the right food. Cats and dogs need extra energy and nutrients, in an appetizing form, to encourage the recovery process.