I recently adopted a female panther, knowing before hand that she had a few flaws. When I got her, she had these greenish, grayish 'callus'/wart looking growth on her back, and her end of the tail. It also looks like it 'attacked' her feet, eating away at them. My vet does not know what it is. I have tried to see that maybe it is just skin biuld up, but apart from pulling away a chunk of skin/growth, I do not know any more.