I don't frequent this site often, but everytime I do, everyone makes me feel better. My 17 yr old cat, Max passed away last night. I came home from work and he could hardly breath. Raced him to the vet, they put him on oxygen and said he had fluid in his lungs from kidney failure. Max was fine the night befoe and the morning of. It was so strange how it came on durin the day while I was at work; such a drastic change. Does kidney failure cause fluid in the lungs? Max was my companion, my sleeping buddy, and best friend. I don't know what I'm going to do without my boy. Thanks to all for your support.