Head-Halter A humane and effective alternative to choke and pinch collars. Gentle Leader head-halters work by steering the dog from his face, in a manner similar to that used on horses and other livestock. Halters make it easy to stop barking dogs by closing their mouths. They also make it easy to control overly enthusiastic or reactive dogs by turning their heads away from whatever has them excited, thus breaking their eye contact and diffusing their reaction.
Most dogs learn to quickly accept halters.
Although halters offer good physical control, a dog can still open its mouth to pant, play, eat, drink, and even bite if so inclined.