kpwlee
Posted : 12/7/2008 3:07:27 PM
OK I did not closely read all the posts but feel I can add my two cents in a couple of areas -
1 - dog culture in the UK IS different than in the US. Just the fact that by and large the vast majority of homes in the UK haved very small yards and are fully privacy fenced (my experience in my 7 yrs there) and dogs therefore MUST be taken out and about so are better socialized and certain behaviors are much better instilled. (although I've seen some doozies on Its me or the dog LOL).
In the US you have many, many rural areas where dogs are just sort of part of the landscape. They never get truly socialized outside their yards or families and many dogs are purely 'outside' dogs. Yards can be huge and aren't fenced because it is too costly or not feasible etc. I am not defending this approach to dog ownership just stating what I have seen.
My point is that in the UK dogs are much better contained because it is easier and the culture is to do so. In so much of the still wide open US it is not the culture to contain your dog.
This is clear in the massive dog overpopulation problem which is very obviously not created by spayed and neutered dogs. I recall that there was a horrendous cat overpopulation issue in the UK, which I certainly was painfully aware of everytime I tended to my gardens. 
In the US I feel strongly that for the average and less than average owner it is essential to get their dog spayed/neutered. If all owners were responsible I would say otherwise. But things I see here in NC have convinced me that owners aren't responsible. In 2007 250,000 animals were euthanized in NC. I fear what that number would be if there wasn't a spay/neuter campaign.
I am not in a position to discuss whether males are more or less apt to fight if intact. I will say that humping and mounting behavior doesn't seem terribly related to being intact or not as most of the dogs I've seen doing this are altered (male and female)
Three dogs have tried to mount Bugsy only one was not in a play situation and B kept all three of them off without a growl or snarl. One was a small BC and B had other dogs around so paid him no mind. One was my friend's intact male lab who stayed with us for a few days and they were having a blast seeing who was top dog in wrestling. And one was just ridiculous, a male belgian shepherd and a female greyhound who were packmates (and both altered) doubled up on B with the greyhound biting at his neck and the tervuren trying mount him. It sucked and I was pissed as the owner just watched. I broke it up immediately and let hte owner know his dogs weren't 'cool' and he leashed them and left. It appeared that the owner wanted them to do what they did which peeved me. Still does.
B has never tried to mount a male or female. He also has never growled or snarled at any dog. I cannot be sure whether this is to do with him being neutered so young or if that is of no relevance. With him dogs seem to be naturally submissive.
anyway that is my two cents
I don't think that having balls makes males naturally more aggressive but overall think neutering is best for non-breeders and non-show dogs