If that kid or dog is trying to kill people, then maybe, depending on the circumstances. Obviously if it was an actual kid, you would have to approach the situation with the care it deserves...but also, for example, I would have literally zero qualms about running over a minor committing a school shooting if that was the only option to stop the violence.
Like if it was a person in a different uniform using a baseball bat instead of a car you wouldn't bat a fucking eye at someone using a weapon to defend innocent people.