Hi TamTam/everyone. I'm terribly sorry to hear that Buttercup past away. This is going to sound so crazy but I lost my sweet little Petunia yesterday too from the same problem. She was my 3 year old RIR. I was reading this thread over the past few days hoping for a happy ending. I took Petunia to the vet about 3 times since June when her belly started swelling. I took her last Tuesday because I was too afraid to do the draining myself. He did a rectal exam and told me he found a lump which he said was cancer. After the doctor drained the fluid I noticed she was so skinny. She was interested in food but would not eat her layer food and turned her nose to most of what I gave her. She would still eat bugs and worms and a few other things. By Sunday I started to feed her by hand because she just turned her nose to everything and her comb was purple. She past away in my arms too Hearing your story made me realize there was nothing more I could've done.