I've recently purchased two young red eyed tree frogs from an expo. They were both very healthy upon purchase. But after about about one of them developed a discolored spot on its back. I thought i may have been a bruise at first, but it seemed to grow into what could possibly be a fungal or bacterial infection. It does not seem to effect his normal activity. It does not seem to be getting worse, but it is not getting better either. Any insight on how to treat it would be greatly appreciated.