Sword is no good, by the time you have raised the damn thing to swoop down, the dog will have you by the jugular and bring you down.
You need one of these, 3d printer friendly.
(might take a while to print though, so get crackin)
Just remember to keep it by the back door, next to the clothes pegs.
I have witnessed a Bully XL attack another dog in the local pub, the fight got broke up pretty quickly, and the owners could hardly pull it back.
Anyways the dog was banned from the pub and that was several months ago, since then I saw where it lived recently I was shocked to see it in the...