I'd be interested in consulting the primary source lit about a few things (like, if S/N increases chances of obesity, are some of the other issues they're associating with S/N actually related to obesity rather than S/N itself or did they control for that) but overall better than a lot of the stuff out there. Looks like they tried hard to be thorough.
I still think from a population standpoint, S/N is important. Responsible shelters and rescues should be doing it before animals are sent back out as should most owners because rather than a .04 lifetime risk of some ailment, these unwanted puppies are looking at more like a 95% chance of euthanasia, but on a dog by dog level, I'll agree the evidence is mixed.
Very interesting! Good case to be made for later procedures but still cannot out weight the value of S/N in regards to population control.
My first female GSD, Lucky, was spayed at 2 years. She had hypothyroidism, hip dysplasia, cognitive dysfunction, spay incontinuence, and diabetes. She certainly did not benefit medically from a later spay.
My fisrt male GSD, Wolf, was neutered at 1 year. He had hemagiasarcoma.