This post takes me back to the 50s when I was a kid with a small-town paper route. One customer had a nasty mutt that seemed to hate paperboys and always made a run at me on my bike - finally one day he nipped my ankle. The owner was a hard-case, blamed me, not his dog, etc. Small town marshal would do nothing about it, so I finally filled a water pistol with a mix of Clorox and water. One or two squirts across the dog's muzzle convinced him to avoid me completely after that.
Today I probably would be busted for animal cruelty, but it worked back then. Now I just carry pepper spray.