I don't know, I just put the harness on him, opened the door, and let him do whatever he felt like doing! He didn't have any problem with the harness and leash, but he was a little intimidated by his sudden freedom, and not too sure where he could/should go. He was 2 years old when we first took him out on the harness. Even if they just lay there and refuse to move, it's still nice to get them out in the fresh air.