Hill’s nutritionists and veterinarians developed Prescription Diet z/d Small Bites clinical nutrition specially formulated to support a dog’s food sensitivities. In fact, z/d Small Bites is clinically proven nutrition to help avoid adverse food reactions. Hill’s Prescription Diet z/d Small Bites Dry Dog Food is a complete and balanced food that provides all the nutrition your dog needs. Please consult your veterinarian for further information on how our Prescription Diet foods can help your dog to continue to enjoy a happy and active life.