bloated stomach and eyes in Oscar

Question
I have an orange and black oscar whose around 3 years old. In the past month or so his stomach has gotten huge and his eyes seem to be protruding more then normal. He seems to be breathing really hard with his mouth wide open.He has stopped eating and I'm really worried about him. I have talked to people at the fish store and have tried treating him with various over the counter medications but obviously nothing has helped and hes getting worse. Do you have any idea what is wrong with him? What should I do? I don't want to see him suffer.

Answer
Hi Nicole,
Your little friend has "Popeye"  This is mostly caused by poor water conditions, and injury.  Poor diet may also be a cause, a lack of vitamin A.  It could also be caused by fluid build up behind the eye, but this is rare.
You must treat him as quickly as possible or he may lose one eye, or even both.  Do a 25% water change, and make sure there is no ammonia or nitrites in his water.  If ammonia, or nitrites are in his water, no medication will help, so make sure they are down to zero.  Buy "Ampicillin" and treat him with this medication.  You may have to order it online if your pet store does not have it.
Feed him peas so he can clean out his system.  He should have peas once a week to help him waste.  On the day you feed him peas, feed him nothing else.  Do water changes of 15%-20% every 4 days to make sure his water stays clean, and free of ammonia or nitrites.  
An Oscar must be kept in clean cycled water, and have a good diet.  
I hope this will help, and that the little man will recover.
Lynda