Good ointment for a puncture wound on a horse?

I've always used scarlet oil, and it is usually easily available and not very expensive. You could also use Betadine (intended for humans) but I'd dilute it a bit. I think as long as you keep it moist and covered it should heal well, since you are already giving penicillin. By the way - STUPID thing to have in a horse pasture - are they planning to remove it? I might talk to them about that. At the very least, hope they're paying your vet bill! (Last place I boarded my horse found a coil of barbed wire lying around in a field. Brilliant. But they did pay for my penicillin).