Hills Z/D ULTRA Allergen-Free Dog Food 17.6 lb Formulated with Hill's Hydrolyzed Protein System, highly digestible proteins that minimize the chances of adverse reactions to food No intact animal protein to help avoid adverse reactions to food Highly digestible carbohydrates and fats to help reduce gastrointestinal workload Increased in omega 3 and 6 Fatty Acids to help nourish the skin Added antioxidants to control cell oxidation and promote a healthy immune system and skin barrier function