Thanks all I really was starting to worry. I wonder how much melafix it would take to treat that tank. I havent had to do anything to that tank except change and vac the gravels..
My guess is that it's a disease with the simple common name as Hole-in-the-Head disease. It's a hole that widens the sensory pores in the heads of large fish, oftentimes those that are fed with live food. Check the water quality and post your results.
Hole in the head rarely affects catfish and is usually only assosiated with large Cichlids that are kept in poor water conditions, if the bacteria which cause HITH were present then i would have expected the oscar to be suffering long before the plec showed any signs.
When I first got the oscar I kept him in a 55 gallon tank. And he did have hole in the head. But that was over a year ago. Could that be the cause? But I have only had the pleco in with the oscar for a few months. And I already had the oscar well a long time before I put them in together. As far as I can tell the oscar looks perfect to me..
I doubt it's hole in the head as that starts off as pitting, but if left unreated it could turn like that, but for some reason i don'think it is hole in the head.
I have started treatment like CFC said and see what that does, If it isnt any better in the next week I will go to a stronger medicine and see what happens. I have grown quite used to this pleco and he loves his new home. And I want to keep him around for a while. Thanks to CFC and wilder for the help I will let you all know what happens.