I had a Siamese cat that was the most precious, wild and affectionate cat I'd ever had. At 15 1/2 years he started acting different--lethargic, quiet. But, he never failed to meet me at the door when I got home. He did not have the twitching everyone is talking about, but one morning he tried to get up and his back legs were paralyzed. He was scared and kept trying. I rushed him to the vet, and everything was wrong. He'd never had a sick day in his life until then. He didn't improve so we made a mad rush to a university animal hospital 300 miles away (and about 45 minutes before we got there he was in the worst pain I'd ever seen), where they discovered he had a 'saddle thrombus.' A blood clot wrapped around his spinal cord. It must have been a slow process, but maybe not. It wasn't curable and he had to be put down. It was the most horrible death I'd seen. I'm writing this because of the paralysis he had in his back legs that some of you mentioned. Maybe it can be checked out with your precious cats. Mingo was the love of my life. Good luck to all of you. I wish you the very best.