I don't have any animals, but, one of my friends does and two of his snakes have gotten RI before. Luckily, he spotted it during an early stage, so he didn't go to the vet. Instead he did this:
http://www.youtube.com/watch?v=hNNTr...feature=relmfu
It seemed effective enough, but, I'd advise if it's at a later stage, this might not help.