How about a fatter face...not usually something that you ask for from a plastic surgeon. When looking at images of real sheep, their heads are thin, but there neck creates an extra ruff...that gives the appearance of a fatter head.
In this case, I brought the nose and eyes lower. For realism, the nose should be lower but the eyes should be higher. This arrangement is more dog-like, but cuter. Yet definitely not a sheep dog.