My Lab/Pit is also a killer. Anything that comes into my fenced yard is made dead. I have bad dog signs all along the perimeter fence but you'd be surprised how many idiot kids will come by and antagonize her... that is until I show them the signs and tell them that it's not smart to tease a dog because if some dogs get pissed enough they can easily get over the 4' fence and wipe the stupid grins off of their faces. They don't come back again.
I no longer let her out alone to prevent Darwin's theory from being realized.
