I switched Jaxon to Canidae at roughly 12 weeks. I (and he) love it! At the same time I switched Jaxon from puppy kibble to Canidae, I also switched my 9 year old Sheltie. She also loves this food. I read that puppy food can do more harm on larger breed puppies especially because of the increased protein and calcium. It promotes fast bone growth, but the ligaments and connective tissues can not grow fast enough to keep up.