I think you just have to change some water and to let him alone for about one week... During that week, he is going to recover... That's not a very important damage and wolves heal well and fast
I advise you to not put your channel cat back with him... I'm also suprised he hasn't already eaten your corydoras !!!
Well the wolf did not make it. I think he was sick when i got him. I got him thursday 6-8-06.I have had 4 cory's and 2 catfish in for a month and they are still doing well. So i may look into another. Water condition is good. So i only think he was sick when i got him.