Should be mandatory reading for everyone that's getting a puppy!
This is an X-ray of a 2 week old puppy( 1. Picture) - look at how far the bones have to grow before they become a proper bone joint!
This is why you should never let puppies jump, walk up/down stairs, over exercise or over train.
Doing to much impact activity at a young age can cause serious issues later in life, or even at a young age as hip dysplasia and other orthopaedic conditions are rising in puppies!
Remember the puppy rule for every month increase activity by 5 minutes. For example an 8 week old puppy only needs 10 minutes of physical activity a day - a 6 month old (2. Picture) only needs 30 minutes a day of physical activity!!