Manage your cats food allergy or intolerance with nutritional support from Prescription Diet z/d Low Allergen Feline canned cat food. Your cats adverse reactions to food can cause serious skin and stomach problems. This condition is usually an abnormal response to a specific protein in food. Hills Hydrolyzed Protein System helps your cat through a process that eliminates animal intact proteins and significantly reduces the possibility of an adverse reaction to food. For cats, most allergic reactions occur as a result of beef, dairy products and fish. Prescription Diet z/d contains none of these allergens, and therefore its nutritional formulation may also be useful for pets with a variety of conditions. *Offer valid on a single Hill's product AutoShip per account per year. Offer resets January 1. Maximum savings of $20.