I do not know, i watched a very smart shep once who was 9. She had been with her family for 9 freakin years! they left her with me for about 24 hours. She had a blast, lots of plays and walks...slept right at the end of our bed all night. When her daddy came back to get her she stood at the door and put on a very large show of snarling growling and barking at him, she stopped once he told her too and she went home with him as happy as could be.