Just talking here... I have had pups of all ages running around my place for the past 12 months. I let them run free (they are still confined to 3 acres) until their about 9 months old. If you spend a lot of time outside like I do then you really get to see them grow. Not only is it great for evaluating a pup but its very entertaining at times. I spend the last 30 minutes or so of every evening sitting on the porch unwinding and watching the show.