Depending on the dog's weight, if he's not chunky and moves a lot you can go up to 8 months. Puppy has a lot more calories n more nutrition for the puppy stage. I personally dont like to change to adult too fast. It's extremely important for all puppies to get the proper nutrition while a pup. But if he's growing too fast like my GS was....6 months 50lbs. He was on orijen puppy. Went to orijen adult. He was a special case. Just kept growing non stop. Again if Diesel is growing at a steady pace, very active and has no issues, I dont see the rush. Guideline are great for sure as they are there for a reason. But some dogs will need more or less than what a guideline says. Bottom line is your dog's growing pace. Ok that was my 2 cents.
