It's one thing if they twitch and mumble a little -- this is something different and far more serious.
Looks to me like the dog is having seizures. The staggering and the odd barking is typical of the mental confusion that follows on a seizure.
They need to get the poor guy to the vet for some meds instead of just making movies and laughing at him . . . .
Yes! I get very upset that people sometimes don’t see the obvious... and agree that was more of a seizure-like action than dreams, especially the way the dog acted when he was standing there... breaks my heart.