looks like a bit of both. i dont know anything about fish, but good luck!
billandnancyskoi
Jan 24, 2007 9:58 AM
that is a real bad ulcer it is a bacterial infection.i can help you.look on google and find NATIONAL FISH PHARMACEUTICALSyou want to buy sulfa,,oxytetracycline hydrochloride,,koi fix for food,,do as it says and this should fix it now you have to put the fish in a tankto treat it.hope this helps you.