Hmmm, I have no idea what to do anymore...

I've treated for ich, gill flukes, fungus and bacterial. The other oscar seems fine. The water tested good, I even got a new test kit to be sure. Sometimes she shoots across the tank like somethings biting her. When she scratches, she does it so hard that scales float around afterwards. I'm totally stumped. :-?
Anyway, here's some pics of her....




and this is a shot of her "dirty looking head"...



Other than her dirty looking head, I can't see anything that would be an issue. Got any ideas?

Wow, Izzydawg, what a nice oscar! :thumb:

I've had fish behave the way you are describing in the past...Not scratching themselves enough to cause scales to fall off, but the darting and unusual behaviour are things I've seen in my EBJD...It's almost as if something is going on "internally" that is spooking them? Something you can't see?

Unfortunately, it's never been something I could get a handle on. It sounds like you've tried all the meds I would have recommended.

Does she ever appear to "twitch" when she's sitting still in the water?

How long did you treat for gill flukes? What did you use? (They can be very hard to clear up, so this is something I might consider treating with again, for lack of any better ideas...PraziPro would be a good choice...)

I wonder if the "dirty head" is just some changes you're seeing as she grows older...How big is this girl? How long have you had her?

I'm going to pm TheFishGuy and ask him to take a look at this. He's got more experience with oscars than I do...If it's not gill flukes or something neurological, I just don't know what to do next.

Well I got her when she was about 5" long. I don't know how old she is. They are in a 100 g tank, and the only others in there are 3 3" siamese algea eaters. I do a 60% water change weekly. I never feed live fish, I use Hikari cichlid gold as my staple pellet, and give a variety of treats once in a while.
...Also, after each treatment of meds I put in cycle as the meds were not good for the benificial bacteria.
This girl is about 11" long. She is still eating well, but likes to hang around the heater.
She is not twitching when sitting in still waster. The fish shop around here does not carry prazipro. I used was AAPLUS, Anti-fluke treatment for fluke parasites...says it effectively treats gill flukes, body flukes,& fish lice. I treated for this once, and before that I used Malachite green, for ich. I've also treated with salt. Right now I'm just happy that she's still eating good.
She does swim around with my tiger oscar selvester at times too. The scratching seems to come in spurts.

Gill Flukes would be my 1st thought, too. Mainly because I went through one HECK of a stubborn bout with it a few months back with some new fish (quarrantined thank God). Now I treat with API General Cure (the better med) for 2 full treatments.
When some people use tap only with large water changes they'll report their fish are "itchy" afterwards. So the person that mentioned that might be right. Does your Oscar do it right after the water change? Or several days later?
What I'd do (not that anyone else would) is re-treat the entire tank with Praziquantel. With that much scratching I think there's something going on besides big water changes causing it.
For the record I do 40%-75% water changes twice a week on my 3 Oscar tanks. No more than 35%-40% (max) is straight tap, the rest is aged. If aged/heated/aerated water is used on a regular basis there should be no difference between it and the tank water. (Except no nitrates in the new water obviously).
PS The stuf called "Cycle" is completely worthless and a waste of time, it doesn't work. The meds you mentioned won't hurt your benificial bacteria.