green terror- dime sized wound

Question
I have a six or seven inch green terror, that woke up the other day with a few scales around his dorsal fin raised up. It looked like he had just scraped against something. I changed some water 1/4 to 1/5 of the tank and adding a little salt. He lives by himself (mostly, 3, 1' cats) in a 55. The next day the area had increased in size and color. It is about the same size as a dime, and is lighter. The "wound" is not fuzzy, just looks like raised scales, but their is something wrong. I have been doing 1/4 water changes daily since I noticed it, clean water never hurts. Any advice is welcome. Thanks

http://i178.photobucket.com/albums/w272/jmerchant21/GreenTerror002.jpg

Answer
Mark,
I am not clear on one thing. Is he in the tank by himself or are there other fish in the tank? I would check the tank decorations to see if he could have scraped himself against anything. If he is with other fish, there might have been a scuffle and he is worse for ware. The salt in the tank should help him heal. At this point there really isn't anything that you can do. Just continue to keep the tank clean and keep an eye on him. If things change for the worse, let me know. Good luck.