Pull your piece and tell them they hit that dog again they're going to answer for it. No one is going to give you lip and they're going to think twice about it even when you're not there. But you need to distiguish a habitual animal abuser from a normal person who is frustrated with the dog in one particular instance and doesn't know any better. Because there is an important difference. One is ignorant and can be taught and feels remorse, the other is a sociopath that lacks a conscience altogether.