I agree with CJ. Intact or not certain dogs need more leadership and/or don't get along. It's the way it goes. Usually males are more likely to pick fights with each other- but bitches are more likely to get into really serious fights.

And opinions and experiences vary with breed, number of dogs, goals for the dogs, and experience. I peronally know at least 4 sprint mushers who keep a dog team in the house (up to 12 dogs)and insist on nuetering/spaying most or all members of their pack. I think partly this is because they don't want to deal with female-in-heat separation and male crazyness in a home situation, but they also do say it limits aggressive behavior in a pack.

Then again, the musher I got my alaskan husky from lets his intact males and females run free in a large fenced enclosure every day- with supervision. But he is very much a natural alpha male which does make a difference, for sure.

There was an interesting thread on sled dog central about a major distance musher (Susie Rogan and Hans Gatt) trying to go to a free-run kennel. They had too many fights and had to give up the experiment. This may have been due to many different factors, but there's no doubt that there can be more fights when there are a bunch of intact males and females. Based on conversations with other mushers who do spay/nueter all dogs it sound like fights are might be more likely among intact animals. However, this may be due to female heat cycles and mating- based aggression (by both males and females).

You need to factor in a major human-leader element as well. Some people simply naturally get more dog-respect than others. These people may be able to control a group of intact dogs, while a less-natural leader may not.

Certainly, the decision to spay/nueter is a personal one. Don't make it based on someone else's input. Do your research, observe your dog, and do what you feel it right for everyone involved. The meanest dog I ever met was a spayed female who went after my nuetered male.

Guess the long and short of it is that there are many different opinions on this and I observe people and their dogs and chose who's input is worthwhileand who'se input is worthless.