Hills Prescription Diet ZD Food Sensitivities Dry Cat Food is a delicious kibble that's been formulated to help reduce skin & gastrointestinal signs caused by adverse food reactions.Hills Prescription Diet z/d Cat food is formulated to reduce skin & digestive signs from food intolerances. It was developed by Hills nutritionists and veterinarians. This food is formulated to promote an environment that makes it difficult for struvite and calcium oxalate crystals to form. It also has clinically proven antioxidants to help support a healthy immune system. Please consult your veterinarian for further information on how Prescription Diet foods can help your cat continue to enjoy a happy and active life.Food sensitivities are so frustrating, z/d is made with a very tasty hydrolysed animal protein designed to be gentle and avoid detection by the cat's immune system, helping your cat feel better.Please note - for customers who have previously fed this diet prior to the inclusion of ActivBiome t