She's hospitalized for at least one night. She's severely dehydrated and she's lost a ton of weight this week, so they have her on an IV drip, which means the return of her personal antichrist: the Cone of Obedience. Photo of most recent encounter:
The vet rattled off a bunch of theories, from the treatable to the terminal. We'll know more tomorrow. I'll post info as it comes in. Thanks to all who've expressed their concern.