How far does your puppy run, Atka? Just curious. No one ever suggests one can not walk or trot or leash-train any puppy, if you mistakenly got that impression from any post of mine,(?) it's just the distance recommended for trotting, or the distances recommended for actual running, or the heights recommended for puppies to be jumping, seems to be debatable. and no one has said the damage shows up in the puppy. but later on, when it is mature dog, or even a senior dog, it could be prone to hip damage or early arthritis, but sure, as a puppy, the puppy will seem fine.