Cayenne went to the vet yesterday morning. I consider it a great trip because she did not pee, poop or puke in the car and because I spent less than $100 there, which may be the cheapest trip to the vet with her ever. Cayenne has less positive feelings about it because it did involve riding in the car, and seeing and hearing other cats and dogs at the vet's office, and being poked and prodded by the vet, but whatever. It was good for me.
The vet said her belly is infected and she has antibiotics now, which of course she enjoys (not). He also said that, unfortunately, getting the sore on her belly to heal will be very difficult because the sore spot in on one of the tumors and apparently these types of tumors tend to end up cutting off their own blood supply as they grow, which then causes the tissue to break down. We want to try to prevent infection, though, because she could easily get very sick and end up dying from infection long before the cancer has a chance to kill her. Those weren't his exact words, but that's the bottom line.
However, other than the infected belly sore, she is in good health. She actually weighed four ounces more than she did the last time she was at the vet. She was also very vocal in the car, loudly announcing her displeasure about the trip, which is annoying and headache-producing, but it's normal for her and the last couple times we went to the vet, I was actually a bit concerned because she was quieter than normal in the car. I think she was quiet because she wasn't feeling well.