How do you treat warts on cows teats?

Your veterinarian may have a remedy to try, or you can shop around for a topical ointment to remove the warts. Some people swear by honey on the surface covered in duct tape (yes, that would hurt a lot to peel off, so have some common sense about trying it); others pick at the wart until it bleeds a bit to get the immune system to knock it back down. There is some possibility that Compound W or another commercial human wart remover would work as well, but be aware that these are typically caustic compounds that will hurt if it touches normal teat tissue.

Regardless of what you try (there isn't a single best treatment - even surgical removal isn't necessarily a good option in this location), make sure to keep the medication away from cows or calves that may try to chew on the teat or eat the medication. Also, if the cow is in the milking herd, use NOTHING - there is a risk of the medication getting into the bulk tank and could cost you the entire milking harvest.