Purina Ulti-Pro Helps dogs lose the fat, not the muscle. As dogs trim down, weight loss can come from two places-fat and muscle. The Purina Ultri-Pro Enhanced Protein System gives your dog extra protein needed to minimize Ulti-Pro Enhanced Protein System gives your dog extra protein needed to minimize muscle mass loss during weight reduction, resulting in a leaner, healthier body. Keep muscle mass loss during weight reduction in a leaner, healthier body. Keep your dog healthy-Keep his weight down and his muscles strong-with Purina Fit & Trim with Ulti-Pro. Delivering healthful benefits for success.