My dog was laying on the bed tonight and her head started going up and down so hard her jowls were flapping. I though it was a seizure but she's never had anything like this before. I held her for a while and it stopped but after about 2 hours she threw up and it happened again. She has had no trauma to the head and hasn't eaten anything bad, that I know of. I've never seen anything like this before! She is a pitbull that is about 11/2 yrs old. Please help.