Same as for a human....a well rounded exercise program. Swimming (some OEB's can..some can't), weight pulling, jogging, stamina building exercises...you get the idea. Food...good quality food with calories to match the exercise level.
A word of caution...if this is a puppy, you'll have to wait until the bones are developed for some of this work.
A word of caution...if this is a puppy, you'll have to wait until the bones are developed for some of this work.