Cat is on the way to a 24hr vet now.
- Distressed howl from hallway. Cat was hardly standing, legs splayed, legs bent.
- Head shaking, obviously disoriented.
- Eyes flicking left and right, rapidly. Not tracking on external object, pupils fully dilated.
- Not responsive to external stimuli.
If it was a human, I'd say one too many of the wrong kind of pills. By the time we'd phoned the animal hospital and the vets she was more responsive, but still disoriented and lethargic, and had thrown up.
She's in the cage and should be arriving at the vet in a few minutes from now.
Update: Cat is spending the night at the vet for observation. Tests are being done. Appears to be neurological, but there are other conditions with similar symptoms.
Vet: "It's either very minor or very, very serious."
She seems okay. No further problem while she was with the vet. Potassium levels slightly low, glucose levels a bit high. Neither of them indicative of much of anything.
It's possible that she's become intolerant of her arthritis medication - the seizure may have been an allergic reaction. She's back to her usual self, pretty much, though a bit grumpy about all the tumult.
We talk to our regular vet over the next couple days, keep her off the medication and see what happens.