My dog (who spent about 3 months in a shelter) sometimes "talks in his sleep", making sounds like he is scared/stressed about something. Other times he makes ha

My dog (who spent about 3 months in a shelter) sometimes "talks in his sleep", making sounds like he is scared/stressed about something. Other times he makes happier sounds while sleeping. It seems pretty clear that he's experiencing a range of emotions in his dreams, but I don't think it necessarily means reliving specific events.