Natural Balance Original Ultra formula dry dog food helps nourish your dog′s complete well-being by taking an entire body approach. MUSCLES: Real chicken, the #1 ingredient, provides essential amino acids that help maintain strong muscles. IMMUNE SYSTEM: Superfoods and guaranteed levels of antioxidant vitamins and minerals help maintain a healthy immune system. HEART & EYES: Natural Balance adds additional taurine to help maintain a healthy heart and retinal structure. DIGESTIVE SYSTEM: A unique fiber layering system helps maintain healthy digestion. BRAIN: Optimal levels of DHA and EPA from marine sources help support an active, healthy brain.