My gelding had these little scabs on both of his back feet around the coronet band and up the pastern a little bit. I originally thought it was rain rot/dew poisoning. I treated it daily by cleaning it with betadine then putting medication on it and trying to soften up the scabs. He even has some of these on old scars as well. Now, when I remove the scabs, its painful, and underneath the scabs is somewhat like pus and it smells terribly. I'm not really sure how to treat this. It just seems like it won't go away. Any suggestions?