I remain unconvinced that a high protein food is good for a growing pup. John Burns of Burns Pet Nutrition, who is a respected vet and has been producing pet food for over 20 years is convinced that a lot of joint problems he saw as a vet were not helped by feeding too high a protein to pups - it puts excess muscle mass on immature skeleton to quickly. He is convinced that the best route is a slow steady growth so that the skeleton and muscles grow at their own rate and you end up with a healthier young adult.