Quote Originally Posted by basil
ok, what about the male version of this answer, regarding neutering and whether it helps prevents prostrate cancer. And comments on a male's aggression level before and after.
A few days late, but you were on ignore then. I was scrolling down the page and spotted your post.

Anyway, I've only seen a couple of cases of prostate cancer in neutered dogs, and those were dogs that had been neutered at an older age. We see many more cases of prostate enlargement due to hyperplasia and/or infection than we see cancer. Hyperplasia is easily remedied by neutering.
Aggression is also something that tends to be less of a problem in neutered dogs. However, many factors play into aggression as a behavioral problem, and we see many aggressive neutered dogs and many submissive intact dogs.

Early spay and neuter, as well as proper training and socialization is the key.