My GSP is a real hardhead, but I always say it's easier to control an aggressive dog than it is to build up a timid dog. When he was three, my wife got a female Brittany and I had him neutered just to avoid that hassle. Afterward Jake actually became a little more biddable and shows some sign of affection for me, whereas before he was quite aloof. He is probably the best dog I've ever had and I would neuter another aggressive dog again, but only after he has matured. As a comparison, my daughter's Lab was neutered as soon as he dropped at about six months. He's still a pup at four years.
