I feel SO stupid not knowing this.. When I took Skyler to get his shots, the vet asked if I seen his parents, and how big they were. I told her and she said.. At about 3 months, I should switch his food over to "Adult Puppy"..She said with larger breed dogs, you do this so it don't make them grow so fast and when they get older they wont have hip or joint problems. I NEVER knew this... He is now on Medi Cal.