My cat is 3 months old, he's been with us for a month but lately I've observed that sometimes when he's trying to sleep or falling asleep he starts shaking like he's got cold, like shivers. I thought he might have got fever or something like that, we took him to the vet but he said it wasn't nothing, that it was probably normal.

I do not doubt of his professionalism (or maybe I do) but this behaviour just seems weird to me (it's the first time I've had a pet). He only shakes when he's trying to sleep. Is this normal? As I said, it shakes like if he's got some chills.


I know it's normal for him to shake ONCE he is completely asleep. This happens before he gets into REM

  • 1
    possible duplicate of Why do my cats twitch when they're sleeping? Commented Dec 1, 2014 at 9:34
  • 1
  • No no, I forgot to say that, yes he twitches ONCE he is aslept, but this is different, sometimes he is FALLING asleep, so his eyes are still mid-opened. Commented Dec 1, 2014 at 14:34
  • 3
    Are you sure he's not actually asleep? One of my cats will sometimes sleep with his eyes half open, or with only his second eyelids closed.
    – Spidercat
    Commented Dec 1, 2014 at 15:58
  • 1
    I too have a kitten that does this. He is 13 weeks and when he lays down to sleep he sometimes starts shaking almost looks as though he is shivering from being cold. We just adopted he and two siblings, neither of them do this. It doesn’t happen all the time and I also thought about low blood sugar. Otherwise,he seems very happy and healthy. They have a vet checkup tomorrow so we’ll see what she says.
    – Anne
    Commented Oct 26, 2020 at 11:14

5 Answers 5


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.

  • It is not just a jerk, he shudders as if he had cold. Commented Dec 1, 2014 at 22:30
  • 1
    Probably just a dream, then.
    – keshlam
    Commented Dec 23, 2014 at 18:15
  • It's not a dream, he's barely sleeping. I really think he struggles when he's having this vibrations. I've observed this behaviour more often when he hasn't eat yet, so I'm trying to feed him every 4 hours or so. He's 4 months old now. Commented Jan 8, 2015 at 21:36

By observation and experimentation I've learnt that this behavior shows in my cat when he hasn't eaten in a long period of time (4 hours for example). I'm trying to keep him fed every 4 hours or so.

I'm presuming a lack of sugar or some other enzyme.

Thanks for all your answers!

EDIT: My cat is turning 8 months in two days. He's very healthy aside from a little skin infection he had a few weeks ago, vet gave him some meds and his skin is good now. His leg hasn't shaken in a long while. Perhaps it had something to do with his age?

EDIT: My cat is turning 1 year old in a few days! He stopped doing these weird twitches a while ago. So I believe it was indeed something about his age.

EDIT: My cat is 1 year 9 months old now and he's healthier than ever (I believe so). I haven't noticed any twitches anymore. He started to chase his tail in the bathroom though.

EDIT: My cat is 4 years old now, he's really healthy, his twitches disappeared and I didn't even notice. We feed him every few hours (we usually leave his food for him to eat on his own). We do not let him out, he's a homebody cat.

  • 2
    I know some humans have problems with muscle twitched or cramps at nigh if they're dehydrated or if their blood electrolytes ate out of balance. Might have been a transient nutritional issue while growing...
    – keshlam
    Commented Aug 14, 2015 at 21:11

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 asleep (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 separate 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.

  • I've noticed that my cat does this more oftenly when it's cold! Commented Aug 14, 2015 at 20:41

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.

  • Wow, I never realized vaccination could be the cause, he was indeed vaccinated when he was about 3 months. He doesn't do this anymore or at least we don't notice it now. He hasn't gotten his second shots tho. And thank you for your posts, it's always good to see we're not alone in these kind of situations. Commented Jun 16, 2016 at 20:15

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.

Not the answer you're looking for? Browse other questions tagged or ask your own question.