The tooth-cleaning is definitely off. He'll be giving her amoxycillain with an anti-inflammatory (Aziam) mixed in. He also recommended an over-the-counter medication called SAMe, vitamin e, and low-fat food for a bit. The big thing, though, is to get her to start eating again, and he recommended chicken, ground beef, and liver cooked fresh as good candidates.
Andy is leaving to get lunch and to pick up the Amoxy as I type this. He'll work from home the rest of the day while I round up the other stuff. The vet wants me to call sometime tomorrow or Friday to see how she's doing. If he thinks she's going to be ok he may keep her on the Amoxy for a month or two to make sure that whatever is causing the inflammation is clobbered.
I'm not going to dwell on anything beyond that for now. Gail got a clean bill of health in her annual exam in March. Although I'm kicking myself for not making the connection that she might not be eating/wasn't grooming sooner, I think we still caught it after at most two weeks. I'm also aware that cats will do anything to hide the fact that they're sick, so I'm not kicking myself too hard.
The vet also said her interest in the milk stuff I got was a good sign, as is the fact that all of her behaviors other then eating/grooming are completely normal. She has been very cuddly recently, which is nothing new. She still tries to bury the food whenever she encounters it. She swats Heidi when the little scamp deserves it. She has been drinking water and using her litterbox regularly. She purrs quite often and was even doing so while being examined, at least until the thermometer part. Given where they stuck it, I probably would have done more than growl. For now I'm just going to figure she ate something she oughtn't have and see how the anti-biotics work.