Strange topic i know but just wondered if Reuben is the only dog i have ever known to run with his mouth wide open and his head swaying from side to side! It almost looks like he is laughing and is very funny to watch. He does it especially when running back to me and it is so cute. One day I will catch a picture of him doing it.
a fairly classic behaviour in poor sight is "scanning". The vision is impaired and the dog is keeping you in his sight by moving his head from side to side
wouldnt want to scare you but I would take this to the vet for checkup
George does the same thing but it looks like he is smiling when he is running. Those big red ears going up and down beside that head. The tongue going up and down also. I can tell he is happy. It makes me happy to see him do this. fefe