Warts are viral, they can NOT be treated, they must run their course, just like in human med. we are unable to treat viruses. They look ugly and the virus will live in the soil, but they fall off and don't return, much like chicken Pox, which is also a virus.
They usually affect young cattle, 16 mo is rather old, but young cattle can be vaccinated, to help build an immune responce to future exposure, which may or may not be affective.
Hope this helps
[email protected]