11 y.o green ig has very sunken eyes

Question
and is a tad nauseous or has a lot of fluid coming out of his mouth and nose, breathing with his mouth open, and have no idea whats wrong or what to do! I took him to the one exotic vet in the area and after x rays saw no swelling of kidneys, no parasites or obstruction, she said it could be
-old age (hes only 11!)
-kidney failure
or cancer

his eyes again, are so deep in his head he looks like a skull, i got a new heater a few weeks ago and i think that might be the culprit, could it dry the air so much?
please let me know what to do for the fluids coming out, its very mucousy and already a few tablespoons came out, could he choke on it? could i give him something for the nausea to make it stop? Thank you in advance

Answer
Hello Eden,

Oh my, that sounds terrible for him.
Did they do a blood test on him at all at the vets?
That sounds like a respiratory issue though.  
I understand using a heater with the cold weather but it may have really upset the humidity levels.  Do you know what the humidity levels are?  An upset of the balance of the humidity and temperatures would be enough to cause a respiratory infection.
What are the temperatures in the tank, currently & what do yo uuse to measure them with?  A stick on type of thermometer, a digital probe or a temp gun?

He needs medication, Baytril, really as he is extremely severe.
Here is a site that you can purchase it from:

http://www.allbirdproducts.com/newproductpages/baytril.html

Tracie