Please note - for customers who fed this diet prior to the inclusion of ActivBiome+ technology, you are advised to gradually transition your cat to the upgraded formula over a 7-day period. Please consult your veterinarian for further information.Prescription Diet z/d cat food is clinical nutrition specifically designed to reduce skin- & digestive reactions caused by food intolerances. It is a digestive care cat food that is clinically proven to help avoid adverse food reactions. PRESCRIPTION DIET z/d is a hydrolyzed protein cat food containing clinically proven antioxidants to support a healthy immune system. This dry food has a delicious taste that your cat will love. Food hypersensitivity and intolerance are potentially serious problems that can lead to irritated skin- & fur and ear problems and even gastrointestinal- problems. Cats suffering from food hypersensitivity or intolerance, also known as adverse food reactions, usually react abnormally to proteins in food. If your cat suf