I'm all in favor of treating these incidents as attempted murder. If someone owns a pet, and that pet commits a crime, it should be treated exactly as if the owner committed the crime with a deadly weapon.
Sorry, but the animal has a will of it's own. It's a lot different from an inanimate object like a gun or a knife. You can't always predict an animal's actions, or control it. And you can't watch it 24x7, either, any more than you can watch a child every second of every day.