Duke has been doing this a lot lately and I'm wondering if he's dreaming or having a nightmare: he would be in deep sleep and all of a sudden jumps up, run really fast around and bark non-stop. I know he hears and smells things that I don't, but so many times I feel that not much change in the apartment and he would do that several times a day.
He'll go back to being calm and sleepy again....
Do yorkies dream when they sleep then?