I hope this information posted about the prong collar goes no further, and not another person feels the need to use one on a sheltie. It's like swatting a mosquito with a baseball bat. Take your dog to obedience classes, and duh.... train yourself. Put in the time. People have been very forthcoming with wonderful advice, recommending great books, etc. Train yourself first. With the right instruction all can be turned around. REMEMBER IT'S A SHELTIE, NOT A ROTTWEILER. Enough!