I was thinking just the same thing yesterday when I saw two youths, each with a puppy. They weren’t treating their little pets very well. At one point a puppy strayed into the road and its owner literally kicked it up into the air and onto the pavement.
It’s a tricky thing. The police are making it harder for people to carry knives on the streets so you can see how those people who would have carried a knife would look around for an alternative to make themselves feel safe. A scary dog can be wielded with pride whereas you have to hide a knife away. There’s another advantage for the ne’er-do-well in that taking a dog for a walk is an extremely good excuse for being in any neighbourhood at any time of the day.
There are, however, some terrible flaws in the dog as weapon plan. The first is that you can’t easily get rid of a dog once you’ve used it in a crime. Not only does it leave genetic material all over the place, on you, in your house, everywhere else, but it is also inclined to find you and follow you home if you throw it into the Thames, something a knife seldom does. People are also likely to become sentimentally attached to their dog, even if it does start incriminating them. And even if they do decide to do away with their former pet, it’s not easy. Look what happened with Bill Sikes’ dog, Bull’s-eye.