Theo is on it. Some folks think shock collars are cruel. My wife used to be in that camp, not for long though. Hogwash; it is amazing how quick they learn this way. For instance you dog goes in the street if he comes back to you are you then going to scold him, they don't get it that way. Postivie reforcement is difficult to prevnt it. However shock = "street bad". For my lab that has duck hunted with 50 times or more. I shocked him maybe 15 in his life. It is very useful when used properly.
