For safety’s sake, if the door that you’re going to use for training goes to an unfenced area, be sure to have your dog on a leash. Don’t, however, use the leash to pull your dog back from the door, because doing so will cause your dog to pull toward the door even harder. The muscles of all mammals work against opposing forces, so whenever you pull on a dog, you cause him automatically to pull back. If you pull steadily back on the leash, you aren’t training your dog to stop pulling forward, you’re encouraging it.
