For ANYBODY else reading this thread, you will kill your horse if they haven't been given a Tetanus Toxoid, Tetanus Antoxin, and yearly boosters and they get a serious puncture wound.
It is standard for your Vet to give an Antitoxin shot when checking out any puncture wound. Keep up to date vials of Tetanus Antitoxin and needles/syringe packets in your refridgerator, and learn to give an intermuscular shot. I keep mine in a small, plastic food storage container, with a lid, and cushion it with cotton balls.)
Horses carry tetanus in their blood, but can develop lockjaw when injured. (I can't figure this one out, just know that it's so.)