I have a yearling filly that has had them for oh - 9 months now. I finally called my vet 4 weeks ago and asked himn to look at them just to make sure they were still warts.
They are, and I tried all the home remedies, they just spread all over her muzzle and nose.
I did look up here for a couple of the threads and did some research myself. I got a product called Zylexis, its from Pfizer and it is a prescription. It's three shots you have to give. But I tell you, within a week the warts were gone!
I will caution you, unless you are really set on showing or selling the horse, let it go away naturally. I only chose to do the Zylexis because I wanted to make sure the warts were gone to show.
The other thing I will say, warts are spreadable. So don't house the horse with anyone else who isn't over 3.
I will also add that there are different strains of warts. So what home remedy may work on one type, will not work on another. They Zylexis is supposed to be good all around.