Caused by a virus, these unsightly growths are a harmless rite of passage for most youngsters.
Small crusty growths caused by the papilloma virus, warts usually appear on a young horse’s muzzle but can be found on the eyelids as well. They are primarily a cosmetic concern and will go away once the horse’s body mounts an immune response against them. “Typically we simply try to talk the owner into ignoring warts because, in most horses, they run their course quickly,” says Tia Nelson, DVM, a veterinarian from Helena, Montana. “Then they are gone and the horse usually has immunity against warts for the rest of its life.”
Occasionally, however, warts become so large that they obstruct a nostril or otherwise cause problems. “Once in a great while, we see some warts that are really awful---so thick and large that the young horse has a hard time eating,” says Nelson.
In those cases, she says treatment focuses on getting the horse’s immune system to recognize the virus as foreign and attack it. “We sedate the horse and use a pair of pliers to crush one or more of the warts deeply enough to make them bleed,” she explains. “This will often give the immune system a signal that an intruder is present, allowing the horse’s body to mount an immune response (to fight the warts) faster than when you simply leave the warts alone. Usually within a week to 10 days, the warts shrink up and are all gone. In the meantime, we may give the young horse some bute or Banamine to help with the discomfort while recovering.”