Warts are not uncommon in young horses. Although I have only owned one horse that contracted warts it is not anything that I as a horse owner worry about my horses getting. I certainly would never pass a horse with warts over just because of the warts. I also don”t quarantine a horse with warts. While unsightly they dissipate within a few months. In my own experience with warts, if my horse would rub against a tie rail or something, he might scrape one off and bleed a bit. I’d treat it as i would any other normal scrape with ointment or salve and not worry about it. Remember, I’m not a vet. If your horse gets warts and you are worried about it, call your vet. If you horse gets what you think are warts but you are worried it might be something else, call your vet. Here are pictures of a stallion I once owned and his warts.