My cat shakes its legs when trying to sleep, why?

One of my 2 cats does this and I was really worried about it. We found out that he suffers from feline leukemia and thought it might be connected to that, so the last time I took him to the vet I asked about that. The vet asked me if it only happened when he is falling asleep and I said that from my observations it's only then. She then told me that if that's the case, it shouldn't be a cause for concern and that it's normal. It calmed me down a bit, but it still looks a little scary. As the poster said, it looks like he is shivering from cold and it comes in short spasms, his body shakes for a second or two, then stops and shakes again.

I'm happy that your cat is overcome this problem of shaking on falling asleep My cat 1.3 years old has this problem today, he took the inactivated rabies vaccine yesterday (second time in his life). The shaking is not severe but it prevents him from sleep, but otherwise he is normal. I think this is related to the vaccine (now Nobivac, first time it was Rabvac) I had no problem with the Rabvac Most probably your cat had the rabies vaccine by 3 month of age. This may also be the cause. That is why I'm relieved somewhat by the fact that it was temporary. I only hope that he manages to get some good sleep. I will observe him and feed him more as per your advice. thank you very much.

My seemingly perfectly healthy and well-cared for (micro chips, shots, regular vet check-ups, topical flea drops etc etc) 5 month old male kitten has started doing this, but his brother hasn't. I agree, it isn't the same thing as the twitch when they're falling alseep (myoclonic spasm/hypnic jerk), nor is it dreaming kitty twitches as they chase after that mouse in their dreams.

This, as the poster says, is different. It's a persistent, on/off shivering seperate from purring, that occurs WHILE he's falling asleep. You can tell when a cat is falling asleep as their purr fades and cuts in and out like an engine running out of gas, then stops as they fall completely asleep.

The shivering is whole body but not all at once, so his shoulders/head will shiver, or his haunches will shiver. They sometimes both shiver, but there's usually a switch. It happens on whichever side is uppermost, so I guess it's going on on the other side too.

Having read up on it, and being fairly sure that he's a basically very healthy little guy, I think it's either a touch of low blood sugar - he's not too keen on the new food we got - or he's a bit cold. I've made sure he's eaten something and drunk some water, and popped him on a big duvet.

If the shivering persists, it's vet time, as it could be a reaction to something he's nibbled, a fever, or something awry with his kidneys, but I doubt that.

You may be observing your cat having hypnic jerks.

From http://en.wikipedia.org/wiki/Hypnic_jerk

A hypnic jerk, hypnagogic jerk, sleep start, sleep twitch or night start, is an involuntary twitch which occurs just as a person is beginning to fall asleep, often causing them to awaken suddenly for a moment. Physically, hypnic jerks resemble the "jump" experienced by a person when startled, often accompanied by a falling sensation.