not sure if this is something all dogs do, but my maltese does this about once a week, what do you think it is, a bad dream or what? http://www.youtube.com/watch?v=iqhXZmiv3BY
There's been alot of research done on dog sleep patterns. I don't know any links off the top of my paw. But I'll pat Sophie a bit when she seems to be having a troubled sleep. We don't know her history at all, but she'll leap up out of sound sleep barking sometimes, then wobble around confused a few seconds and curl up back to sleep. The definitely dream.