Essentially stopped most of the pulling as of immediately, however he has learned to brush it off his nose with a little fiddling. The Aussie is a pleaser and knows we want him to leave it on but after a while he gets antsy. That said we do not leave it on our dog full time, it's for walks only. It might be better to start with this when they are very young. The large size is basically shrunk down almost all the way to make it fit the 65# Aussie and I consider that too big, too much extra halter strap hanging off the back. I'll try the medium size next time.