I tried holding the ball and getting him to target it yesterday. It was going really well for a while, but then the lab next door suddenly barked very loudly right beside the fence and Brody ripped the ball out of my hand and growled and shook it ferociously. Another inch higher and I may have lost a thumb. It's really scary the way he grabs that thing. One time the ball was right behind me when another dog barked and Brody grabbed it. It could have been my leg that time. I'm glad he's not fence fighting, but I'm not sure what he is doing is healthy either. Although, when he's finished, he doesn't seem to be stressed, and quite quickly goes back to whatever we were doing before. I never leave him alone in the yard, and he is usually on a leash unless we are training or playing ball.