Have we gotten so far from our agriculture heritage that we can't tell the difference between a barking, excited dog, and a vicious dog? Vicious dogs don't look at you sideways. they look straight at yo. They usually don't bark much either, but display a low growl that ascends with open bare teeth. They were either trained that way or chained on a short leash in isolation. They are usually territorial. Dre was not protecting a territory. He was just excited, and yes probably apt to chase anything including people who run, but absolutely, unlikely to bite.