Sore On My Clown Loach

[mickeys_rose]

Hello all, I am new to the web site.
I have a problem with one of my Clown Loaches. It is about 6 inches long and lives with 2 other Clown Loaches of like size, 4 corys, 2 upside down cats, and a striped Rapheal. In a 55 gallon tank. There are other fish like Tetras and the like.
I was watching the tank this AM and the loach in question just all of a sudden raced around the tank making a lot of splashing and frantic racing around the tank, when I investigated I noticed a large wound on it's side by the front pectoral fin. I isolated it and now I am wondering what to do about the wound. What is the best coarse of action for this fish

 

[LetsBeFriends]

in the wrong section, try posting in the tropical emergency section of the forum, i would help but am no expert on fish disease.