Totally agree with Moonsmom....pick up any book on how a serial killer starts and you'll find a story of an animal abuser.
I agree that any parent can have a mentally ill child...but if the parent is too stupid to recognize this and act on it, then they share the burden of guilt.
Come on, this child is seven yrs old, even a normal 3 yr old would know the difference between having fun and being cruel.
I watch parents with their kids everyday and most are so engrossed in their own lives they don't even notice their kids or care what the kids do as long as they don't bother them.