A lot of good dogs have been ruined by inappropriate use of e-collars, even if the dog was collar conditioned in advance. You may get lucky and get away with stopping a dog chasing something (deer, rabbit, whatever) using an e-collar, but the chances are pretty high that you will cause unanticipated behavior for a long time (like the life of the dog). I agree with David that setting up the chasing scenario so that there is no other outside influence is the best, and probably only way to go. We do that for snake avoidance training and it works. It isn't pleasant for the dog, but it takes everything but the snake and the dog out of the picture and for most dogs, never needs to be repeated. The same will work for deer or other running (prey) animals. Please don't try to do it out in the field on a hunt unless you have absolutely no other options.