Ken's Medical Treatments

My cat son, Ken, is sick with an unknown illness. I know Ken has many friends out there and maybe you all can help him...I've seen two vets and had tests run on Ken but the exact illness is unknown. His abdomen is filled with excess fluids and he is uncomfortable and possibly in pain. He is not eating very much. He may have a tumor or cancer or an undetected heart problem (says vet). His blood work and vitals were all healthy other than his bloating, as of 12/27.They were unable to see much through the excess fluid in his belly and can't see what is wrong. They want to drain the fluid but it's a very expensive operation with recovery care needed and I already spend my funds on two vet visits and tests. I would like to have the pressure drained from Ken's belly and at least know what illness is causing it.