Damn, that is just nasty! How can someone let an animal get to that point? I just don't understand. Stupid idiot!
Hopefully the vet will be able to get him squared away. It's bad and there might be a lot of other things going on too. A little TLC and vet care may go a long way though. Glad you were there to get him and then get him to where he needs to be, whatever the outcome. Poor fella!
I just hate to see such things.