I agree about socializing them early. My boy, is 4. We got him at 11 months from a breeder. He was not socialized, and spent most of his time running with a couple of other dogs on the breeder's property. He is so afraid of little kids, that he tries to run from them. One day, he was off leash at our local park and looked like he wanted to run home when a younger kid approached him. If he is on leash and a child approaches, he tries to get his head out of his collar to get away. I think at this point it is going to be very difficult to make him comfortable around kids. I do agree with previous posts that stated muzzles may just make the dogs more nervous.