Oscar acting weird!

Question
Hello, and thank you for your advice, however now my Oscar is different and i do not think it's the pleco.  He has what i believe is ich. (white spots all over his body). He is acutally roughly 4 inches in a 35 gallon.  We changed the water (50%) and treated him with Quick Cure (blue treatment) and antibiotics (Marex). His colour is very grey and he still looks as though he is chocking at times..and is spitting out from his mouth as well as gills white chunks (the best way i can describe it). He seems very stressed and usually stays nose down at the bottom of the tank. It also looks as though his fins are missing pieces from them.  We had feeder fish in the tank, and took them out, and will NO LONGER feed him that at all!!! He seems to be doing good with the Pleco though, and the Pleco seemed to be almost seizuring like Oscar was doing. He has no ich but does have a white patch since we got him on his back. Please help, I can't see him die!!! Thank you SO much!
-------------------------------------------
The text above is a follow-up to ...

-----Question-----
I have a question..my Oscar has been acting really weird ever since we got a pleco..around the same size as him..roughly 6 inches. They are both in a 35 gallon tank that is really tall. Now, Oscar seems to be almost shaking his tail alot.Vigourously shaking his body at time, and opening his mouth ALOT. and really wide also..almost like he's chocking i guess.  Something like film seems to be over one of his eyes. and he bangs the tank almost to try to get my attention or something. i hope he's ok. or will be. please help!!!! he means so much to me!!! :S lastly his colour looks off. please get back to me asap if you can help. thank you
-----Answer-----
Hi Sabrina,
 I assume that you can still see/find the pleco?  I ask because most likely one day you won't -- your oscar will have tried to eat it.  The fact that the pleco is the same size as the oscar won't deter the oscar for long.  I suspect he already tried which is why he is a little distressed right now.  Catfish have powerful spines and often they have little bits of venom associated with those spines.

-- Ron
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>


Answer
Hi Sabrina,
 It does sound like it. Unfortuately, you have a bit of a race going on in your tank.  Basically the medicine will start working on the ick, but it takes a few days for it to have a strong effect.  In the meantime, the ick continues to attack your fish.  Hopefully your fish can survive long enough until the ick is gone.  

-- Ron
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>