If it is fowlpox, the prognosis could be anything from he will just look funny for the rest of his days to he will develop tumors internally and die. Fowlpox is just weird like that. And although there is an immunization for it, I know (at least for chickens), once they have it, it's viral, so there's no magic pill for it. It will just have to run its course, like a cold that we would get.