One of my earliest memories is a neighbors German Shepherd devouring my little dog waiting with me for the school bus to come. Not just killed or torn apart, partially eaten. RIP Sandy.

The males constantly assert their dominance. This is the case with a lot of dogs, but it has been my experience that it is most common with Shepherds. Several neighbors over the years have had male shepherds (always named "Max" for some reason) and first thing they want to do is climb on top of the backs of every dog in the neighborhood.