In other words the dog should of known what a gun can do and ignored the command from its master? Have you ever owned a dog?
Cruelty is the intentional torture of an animal.
The owner did not torture the animal. The police shot the animal, again NOT torture.
Animal Cruelty, an offense which isn't codified everywhere thankfully, is an idiotic crime that is bound to be misused. Sure there are folks who deserve to pay for the crime of being cruel to animals, however you have slipped down the slope as will many others by applying "cruelty" to every thing that happens to animals that you personally find distasteful. Nice socialist attitude there bud, I'll have none of it thanks.