Of course they can. Why wouldn't they? A dog can move its head just fine. Don't tell me you haven't seen one do it...
I think I have seen a dog look up before but I wonder if what we see is them looking at someone from far enough of a distance they actually don't have to crane their neck upwards enough to be considered looking upwards. To be honest I never even considered it before until the movie.
Jason
Oh yes, because Paul's work with Wings was so deep, wasn't it? "Somebody's knockin' at the door, somebody's ringin' the bell. Do me a favor, open the door, and let him in". You can't get much more Mensa-like than that.