The latest update is that there is still no sign of any cancer or any tumors. They did some more x-rays and the fluid is not coming back as of now. The heart looks fine so they are ruling out heart disease. She had a fever yesterday but is back to normal now and on antibiotics. They are still stumped but she is doing much better. They need to do some more tests tomorrow but I'm getting the feeling that they won't figure it out. She may have been accumulating the fluid for a long, long time and something like the fever caused it to become more obvious. I said to put a drain plug in her and we'll bring her home and change the fluids every 6 months!
She might be home tomorrow with no adverse effects. I think she needs to be put on the new Animal Mystery Diagnosis show so they can pay for some of it!
So things look pretty good for now.