I don't really know. But there could be all sorts of causes. She could be getting a sudden pain or twinge somewhere. Or if she leaps up out of sleep she could be startled by a dream she is having? Or there might be some biting fly or bug which gets to her...?
Have you mentioned this to your vet? That might be wise. It might or might not be neurological, or there may be another cause which is physical and needs checking. (tenderness in her belly area or something which causes a sudden sharp pain etc)
I was wondering if your dog still has this problem? I have a King Charles Spaniel (91/2 years) that just started this- she is laying down and then real fast jumps up and goes in a circle with her face pointing to her rear but then - real fast- runs to me and wants to get as close to my face as possible! She stares at me with a sad face and she sits, with a little shaking. I lay her down and check out her body, on both sides, best I know how. I see no fleas, I see no rash, I check out her orfices and use colloidal silver spray on them. She gets the anal glands expressed by groomer and is up with her flea and worm supps. I did read about the glands squeezed by groomer on outside and the vet does the inside but I never knew about that.?? But was curious to hear if you are still experiencing this. This is not just when she is sleeping, as other testament said. I can't imagine what this is.But she races around so fast!
My dog did the same. Jumped up from a sound sleep and then would look like she was scared to death. After a long process of tests, xrays, anal glands it was determined she suffers from Sleep Behavior Disorder. Humans get this as well. She is prescribed potassium Bromide. Since potassium bromide needs to build up in the system and take months to reach theraputic levels she was also presribed Clonzepam. For more infomtomto your vet or a vetrinary neurolgist. There is also a little information online if you Google Sleep Behavior Disorder. Good luck!
My dog is a 14 year old siberian husky she is doing exactly the same as your dog ....at first i thought it was her age but like yours seems to be ok when outside i also thought about the fact she maybe see or hear something i could'nt....but she acts the same at my sons house so me as well would like to know i presently live 5 hours from her vet but will take her there if this continues.....shes my ( BABY )
My toy fox terrier was doing the same thing. I took him to groomer and she said anal glands were fine. Got him home that same day and he was still jumping suddenly, scratching and biting at haunches. When he followed me around the house and barking incessantly (not usual behavior) I took him to the vet.She said his anal glands were "very full" even though groomer said they were clear.
When I called the groomer back I was told that most (all?) groomers only do exterior expressing with pressure (huh?) and that only vets do internal cleaning.
All I know is that he is back to normal and resting comfortably now.
My dog started doing the very same thing about 2 months at. No fleas, gland fine.
He jumps up from sleep like something hit him. His heart beats fast, he trembles like he is scared to death, and he walks around with his tail between his legs. He follows me into every room and has to be right next to me. I have begun to wonder if he is being bothered by some animal spirit, myself. He sits and stares at nothing! When I take him for a walk he acts normal. I don't have the money to take him to the vet so am real interested to hear anything other people are experiencing, and what has been found.