This Iams ProActive Health formula has PreBiotics that work inside the digestive tract to promote healthy digestion and strong defenses. Healthy inside. Healthy outside. Designed for dogs ages 1+ year and 50+ lbs, Iams ProActive Health is specially formulated to help maintain your large dog's healthy joints. Protein sourced from chicken and egg helps build strong, firm muscles while seven essential nutrients nourish the heart. Antioxidants help maintain a strong immune system. Crunchy kibbles scrub your dog's teeth with every bite to help reduce plaque and tartar buildup that can lead to bad breath.