is my pleco dying?

Question
A few months ago my other pleco did the same thing before he died..my pleco is around 20 years old and lives in a 125 gallon fish tank. This morning he started skimming the top of the water for air and even though their is plenty of room between the water line and the lid he seems to jump up so hard that he hits his face. I have noticed that one of his eyes is pushed in slightly while the other one looks normal. This happened to my other pleco a few months ago who was also very old and I'm wondering if this is a disease related issue or if he's just dying, also the water temperature is at 78 degrees and he is now breathing heavy and is slightly rocking back and forth..thank you for any help.

Answer
Michelle,
This first thing I would do is check the water. With the breathing hard, it usually indicate there is not enough oxygen in the water. I would drop a couple of air stones in the tank to help add the much needed oxygen. Check your filter and make sure it is working properly. Pleco do jump but it usually means the water is too warm. Make sure the thermometer and heater are working well. With him being 20 years old, he is an old man. They can get a bit disoriented and that might be what he is doing now. Unfortunately there really isn't anything you can do. Maybe lower the water level a little to ease the crashing into the lid. Watch the other fish that they are not picking on him. This could also cause this problem. Let me know how things are going.