Just wanted to add my two cents on the subject of dog collars. We have a very powerful, 100 lbs great dane/boxer/lab mix. We could not control him on walks if he saw a squirrel, rabbit or another dog. A trainer recommended the gentle leader, after we had already tried a prong, choke and plain collars. The gentle leader was a godsend. People always complement us on how well behaved he is now!!! Thanks gentle leader.