This is why I carry “Bear” pepper spray with me when I walk my 10 pound dog.
The, “not on a leash but won’t hurt you” excuse only goes so far. I walk with the spray and warn the owner to get the dog or it’s sprayed. Luckily, my dog is breed for agility and can most likely outrun any dog, but my daughters aren’t and can easily be hurt by someone’s “just a puppy”.
I do not carry pepper spray, but I do carry a Smith & Wesson .38 Airweight when I walk my 30 pound Corgi. People who leave their dogs off the leash do not deserve to have dogs, IMO. I seldom see loose dogs, but if one does show up and attack me or my dog, he's going down.
I have no sympathy for the dog owner in this story, who IMO is the one responsible for the dog being shot.