More good news. Belle is improving in stages. She finally got fed up with her confinement in the guest room and actually walked -- limped, rather -- into the living room to rest on the carpet. That was the furthest she had walked since Saturday. She even had the motivation to put her forepaws on my stomach, the way she does when she is asking for a snack. I picked out a couple of snack sticks and she ate them. The bowl in her room was also empty, so I suspect she had also eaten her breakfast kibble this morning, though I didn't actually see her do it. There was also poop near her sand-box. I guess she couldn't make it in time, but in this case, seeing poop is a good sign. I did see her grooming herself again, which shows her morale is starting to come up. She purrs again when I stroke her, and Dr Casey was happy to hear this report from us when we went to see him this evening.
When we came home, Belle refused to go back to her guest room, but instead returned to her routine of sleeping in her basket under our bed. She's been there ever since.
Dr Casey is helping us restore mobility to her draggy leg. He reminded us to continue the massage and physiotherapy for her and suggested that we try alternating hot and cold compresses on her weak leg to improve circulation. Apparently, the blood vessels expand and contract according to temperature (we learned about this in Sec School physics) and this movement encourages blood to flow. If the heart isn't pumping hard enough, another kind of pump will have to do.
Belle still has a lot of recovering to do, but today's progress has really been amazing. Good girl! Keep it up!