Food sensitivity and intolerance are potentially serious problems that can result in sensitive or irritated skin, coat and ear conditions or even gastrointestinal upset. Cats that have a food sensitivity or intolerance, also called adverse reactions to food, typically experience an abnormal response to the protein in the food. If your cat suffers from adverse reactions to food, it is even more important to feed the right food.Hill's nutritionists & veterinarians developed Prescription Diet® z/d® clinical nutrition especially formulated to support your cat's skin and food sensitivities. In fact, z/d is clinically proven nutrition to help avoid adverse reactions to food.