Hi, Megora. I just read some of your posts in other threads, and impressed with your opinions on neutering.....
Thanks... but remember I can be very opinionated. Doesn't mean I'm 100% right all the time. There are a lot of people here who especially have had experienced with "tougher" dogs. I hope they chip in here.
I have spent lots of time and efforts to train our boy, and I was shocked when I saw the fights. I believe it's my fault if our boy doesn't behave well. I have to face the fact and keep my hardwork on dog training, instead of dreaming that neutering may be helpful.
Please don't get me wrong - if the fights stem from hormonal or macho things going on with your dog, neutering may help remove some of the motivation for the fights, even though you still need to follow up with training and management. You need to manage which dogs your boy is loose or interacting with. The soonest you get a handle on this, the better for him. Since he's still young, there's a good chance you can "fix this".
For training, I recommend looking around your area for dog classes. I attend classes with somebody who owns a fairly aggressive St. Bernard. I even posted a comment last year re/my upset when this dog was heeling behind my Jacks and suddenly started chasing him while growling and snarling. It scared the heck out of me and there were a lot of people who shared the private comments with me before or after class about how they did not trust that dog and didn't want him there.
Fast forward 2 months and the instructor working closely with the owner, and this dog made a complete turnaround.
Now... I don't think this dog would ever be one that could handle being turned loose in a dog park, but as far as being in a crowded space around other dogs, he's doing great. I think that is honestly the goal you want right now.