Some dogs just seem to be born as natural athletes. Other dogs work long and hard to develop their endurance and skill. No matter which category your hard-working dog falls into, feed him the best with Diamond Naturals Extreme Athlete Chicken & Rice Formula for Dogs. Dogs that work hard need higher levels of protein to maintain their lean muscle mass. Protein is required not only for strong, lean muscles but also is needed to maintain the vital organs and a healthy immune system.