Also please note it is very common for fluid to be drained from either abdomen or chest and have it re-appear rapidly. So the underlying cause must be found or this will continue to happen.
Exploratory surgery is very commonly done and it often the way diseases are diagnosed. In this case, because it is the chest, I would go with more blood and imaging work before the exploratory. Heart Disease, Cancer, inflammation of the lining of the chest, blood or lymph flow blockages are all possibilities.
Without an answer and treatment soon, the chest will likely fill again.
Let us know how she does.
I agree with Dr. Vicksman. As frustrating as it is, sometimes advanced diagnostics need to be performed to rule out other underlying cancer, foreign bodies, etc. If you're at MSU, you're in really good hands! I'd also recommend either a CT or MRI to rule out any other cancer before proceeding to surgery, but it will likely add on an additional cost, FYI.
1899billyboy,
Its obvious that you care for your beagle a lot and it sounds like she is in excellent hands.
Unfortunately it can be both frustrating for you as an owner and us as veterinarians when all our diagnostics come up negative. Especially when there is a serious problem going on. In this case I would agree with the doctors at MSU. It sounds like an exploratory may be the only way to get a diagnosis. Before you proceed though I would ask them if they think a cat scan or an MRI may be helpful.
Hope this helps.
Please keep me posted
Thanks,
Dr Vicksman