My fish got bit up pretty bad by one of my jack dempsey fish and i think he is gonna die.
Non iodized sea salt really helps with fish wounds. Its cheap and its easy.
also buy some melafix should help.
i really like the fact that you care enough about your fish friend to help him out when he/she is in pain. fish have feelings too:)
i hope i helped and have a wonderful aquatic expirence
just set pa hospital tank and put your fish in it and add a few bethelyn blue drops depending on the tank size hope it helps