I have to say this, to throw a twist into the mix of the idea. my wife has a catahoula leopard dog. I do not know if it makes a difference but my wife has been defended by her Catahoula twice. the dog has no protection training, has never seen a suit or a sleeve. she plays fetch, thats about it. this dog heard my wife screaming from another room and came and attacked the attacker. another time she was sitting on the couch on the end, when someone reached behind the person sitting in the middle. and punched my wife in the arm. dog got up from lying lauched itself over the couch and nailed the guy in the face. remember no training. brings up questions on how relationships does affect a dogs sense to defend thier handler. And why a dog would need "special" training to know not to bite me.