Um, can I just say that I really hate the term, “fixing”? It implies that the animal is somehow broken. 
As an animal health tech for many years, I’ve seen way too many results of NOT spaying or neutering. Hip dysplasia is primarily hereditary, which is why responsible owners get their dogs x-rayed and obtain their OFA certificates before they even consider using them in a breeding program. I just can’t buy into neutering or spaying as an outright cause of it.
@RosemaryDuck is absolutely correct when she relates what she’s seen, not to mention reducing the odds of mammary cancer, curbing aggression, and preventing territorial marking indoors. I would be willing to stick my neck out even further and add that a good 80% of closing-time emergencies (bringing in a dog hit by a car), occurred with intact animals. An intact male is more likely to put his nose to the ground and take off running at full tilt without paying any attention to that car coming around the curve. Deer and other wild animals do the same thing during the rut.
Are there risks of spaying and neutering causing other issues down the line? Of course. Only a fool would argue against that point. However, the scales tip strongly in favor of having the procedures done when you consider the preponderance of evidence listing one set of risks against the other set.
I currently own a neutered Golden Retriever and a spayed Irish Wolfhound. Every dog I’ve ever owned has been altered and I have no regrets.
May I add that this is a very interesting and enlightening thread.

As an animal health tech for many years, I’ve seen way too many results of NOT spaying or neutering. Hip dysplasia is primarily hereditary, which is why responsible owners get their dogs x-rayed and obtain their OFA certificates before they even consider using them in a breeding program. I just can’t buy into neutering or spaying as an outright cause of it.
@RosemaryDuck is absolutely correct when she relates what she’s seen, not to mention reducing the odds of mammary cancer, curbing aggression, and preventing territorial marking indoors. I would be willing to stick my neck out even further and add that a good 80% of closing-time emergencies (bringing in a dog hit by a car), occurred with intact animals. An intact male is more likely to put his nose to the ground and take off running at full tilt without paying any attention to that car coming around the curve. Deer and other wild animals do the same thing during the rut.
Are there risks of spaying and neutering causing other issues down the line? Of course. Only a fool would argue against that point. However, the scales tip strongly in favor of having the procedures done when you consider the preponderance of evidence listing one set of risks against the other set.
I currently own a neutered Golden Retriever and a spayed Irish Wolfhound. Every dog I’ve ever owned has been altered and I have no regrets.
May I add that this is a very interesting and enlightening thread.