I can't read the link, it says "Page Not Found"
Either way, I got my female APBT spayed at 7 months, right after her first heat. I regret it. She developed incontinence. I wish I would have waited until she fully developed, and I will next time.
I got my male RR neutered at a year and a half. I'm on the fence with it. While it curbed and almost eliminated a lot of his dominant behaviors, it also changed his personality. It's not a bad change, just a different one.
My 11 year old female dachshund is not spayed, and she has tumors. Quite a few. She will undergo surgery as soon as we have the money for it to be spayed and remove the tumors. We got her from my boyfriends parents, and she was obese and had to lose weight in order to be cleared for surgery at her age. She has a lot of hormone problems and she has even once had a puppy abort. Poor girl.
My 6 month old male puppy, I plan to never neuter. Unless he shows some sort of temperament issue, then I will never have him neutered. I just don't see a lot of reason for it if he will not be exposed unsupervised to intact females.
I guess my point is, there are a lot of conflicting studies on the pros and cons of spaying and neutering at certain ages. I think most of us know enough about dogs and hormones and behavior to be able to make common sense decisions based on the dog. Because I truly feel that it is a dog-by-dog thing as to whether or not they should be altered and when. Wish I could read the link, though.