My 13 year old Spanish keeps on having episodes of screaming out and not being able to move very well and then a couple of days later she's springing over the other dogs.  Also on these occasions someone seems to be weeing in the kitchen in the night time and usually it's clean.  There is nothing else of note as such but the screams from her are awful.  Just seems weird that one minute she looks as though it's time to have her put down and the next she's running around. 

Muscle cramps? It isn't epilepsy is it?

sounds like spondylosis   Once the bones fuse again the pain stops, very distressing when they are screaming but it can be treated (but not cured)

Sarah never thought about Spondylosis but seeing as I have it I should of thought of something like that as I know that I can go months with no problems and then have months of hardly being able to move my neck etc.

Have you taken her to the vet?

Yes took her to the vets and all's fine.  He actually said that he wished all dogs half her age had the blood results that she has :d  Think it must be her daughter again bouncing on her so she's now seperated from the rest of the dogs and living the life of riley!

Almost certain that it's muscular or arthritis, she was doing well up until last night when she was rolling around on her back and waving her legs in the air, she span quickly to her right and screamed out and had a couple of small screams during the night.   Definitely dont think it's epilepsy or anything like that as she's fully awake and with it at all times