Also, unless you're raising the feeders yourself, there's a good possibility that they carried in whatever is ailing your oscar. I'd stick with either home-raised guppies or other feeders, or a good quality pellet food.
I think we'll give him another week to try to get him eating again...
Although the more i think about it.. even if by some miracle he does start eating, I would never be able to put him back in the big tank with the other Oscars.