It makes your dog have a better life, and you as well. Not nuetering can lead to serious agression problems. Most dog bites have happened with unnuetered males. What do you have to lose, anyway? The mode swing your dog has after surgery lasts only a day or two, and you just can't let him run and jump as much as usual for a week after surgery. Of course, it's up to you, but I think it's it's better to nuter.