Cayenne went to the vet today. Amazingly, she did not poop in the car on the way there or on the way back. She did, however, pee on the way home.
The bad news is that the vet did not feel her wound improved as much as he would have liked and so he now recommends surgery. I'm still glad I took her to the second vet, though, and that we tried other treatment first. I also feel much better about the choice to schedule surgery because he took the time to answer all my questions, unlike the other vet.
So Monday Cayenne goes under the knife. Hopefully she recovers more easily than last time. Poor kitty.