Horses do bite. I've known several people seriously hurt by them biting. One fellow lost an ear to one, a chuck out of a hip, 3 people who have lost fingers. One fellow has a high dollar pass-a-fina (I can't spell it), horse bite off 3 fingers at the palm and swallowed them. He shot the horse, cut it open, retrieved the fingers and drove himself to the hospital. They couldn't reattach the fingers.
When I asked if he regretted shooting the horse after they couldn't reattach his fingers, ....his answer can't be typed here.....