This is a glitch that happens when I invite my friend to my world. I do not know if it happens on singleplayer, but sometimes, when we try to get on a tamed horse, the horse will INSTANTLY die. I think it has to do with the fact that if you ride a horse, or put a saddle on a horse, sometimes it'll take damage. This happened twice, and we lost some good horses. I would please like this bug fixed ASAP, because my friend and I are going to use horses for transportation, and I don't want one of our horses to die when we are THOUSANDS of blocks away from our base.