Dog owners, are you prepared to shoot a loose aggressive dog if it attacks you or your dog?

Walking my dog in a neighborhood last night (it's rural so no streetlights or even much in the way of sidewalks). Another dog was walking its owner from the other way, we passed it, and as we were about 15-20 feet away, it charged my dog unmuzzled and without owner reaction. Fixed that problem with a few orders and an upraised walking stick, but it made me think:<br><br>If I had to shoot a dog in an attack, would a pistol round of the calibre you carry be enough to immediately drop an aggressive dog, or would you seek a larger caliber?<br><br>And in what non-lethal ways would be effective against a charging dog?<br><br>I always carry pepper spray, walking stick, and my pistol, but I am seeking non-lethal deterrents.