Puppy stage lasts for different lengths of time, depending on the breed. My male English Springer was a puppy up until his death at 13.5. He was still a bouncy, playful, goofy dog, up until about a week before he died. He was not hyper, even as a puppy, but very playful and mischevious. Males are usually puppy like longer than females, in my experience. My pyr is 2 and still gets excited and jumps around like a puppy, from time to time. If you could watch my IW, Caucasian and Pyr race through the house, out onto the deck, into the backyard and then back, you would think they were all just giant puppies. The furniture goes flying, if they bounce off of it, I go flying, if I don't get out of the way, etc. This little cool spell we are having has really energized them. If you have never been hit, by a 190 pound dog, running and jumping onto the other dogs, you just haven't lived in my house. Even a glancing blow can be quite painful. Luckily on tile, you have enough warning to get out of the path of the oncoming steam rollers. It is rather comical to watch. They look like huge puppies, playing and tumbling around. It is very entertaining and we love it, especially when they are grabbing each other by the tail and pulling them backwards. I wouldn't trade my big dogs for anything.
Kathy