I almost always have neutered and spayed my dogs because it was what you're "suppose" to do for health and behavior and preventing unwanted litters.
With my last GSD, he was becoming very dog aggressive and picking fights, but I was thinking of keeping him intact way back then for possible breeding. So he was neutered at about a year old.
My female Lab went through one heat and I couldn't stand it so she got done.
My Doberman, I wish I wouldn't have neutered so young. He was gangly and since then I've read so many reasons why not to neuter, at least not before fully developed.
So, these two Poodle puppies are intact. I only plan to breed one of them but unless there is a reason to neuter, I won't. So far, they only have occasional squabbles over a toy like pretty much most dogs living together. (and human siblings. lol) They don't mark in the house, so far, knock on wood. And they are going to fill out nicely with lots of good, dense bone. I see it, especially with my larger one, Matisse. Other behavior, I am not concerned with. And accidental breeding....not likely. They're under lock and key. Studies show that neutered dogs can be every bit as dog reactive or aggressive and in fact, possibly more so than intact dogs. There just really doesn't seem to be any reason at this point to neuter them. And too many reasons to keep them the way nature intended...with all their organs.
I find it funny that people are so opposed to ear cropping and tail docking but don't find anything invasive or wrong about neutering. Spaying to me, is a little different....health wise. And neutering if one's dog is going to be in contact with other dogs where they might breed by accident...yes. Very important reason.