t pretend to know what this is, but wonder if it could be a
Keratin growth. (
Keratin is a protein which can be soft, like skin or hair, or soft warts, or can be hard, like nails, claws, hooves, etc) I think keratin growths can be quite tenacious, but ask the vet about it. If by any chance it was caused by a virus (like the papilloma virus can cause warts) there may be an anti-viral treatment to stop it ??