Many of the dogs in shelters are not from over breeding, but rather owners who can no longer support them financially, including but not limited to, food, primary vet care, and losing their homes; a close second is behavior problems/training. You do not see litters upon litters of puppies in shelters. When you take into consideration all of the dogs on intake, the “oops litter” only accounts for a small percentage, but the media would have you think differently. Puppies sell, puppies adopt out quickly. UC Davis did release a study done of Goldens and why s/n should wait until as late as possible, preferably after 2yrs of age, but there is an even older one done with Rotts. This one points out that spaying a female Rott at 6mo almost triples their odds at developing bone cancer. The sex hormones are not only crucial to physical development, but to mental as well. The tides are turning as we delve deeper into this and more research is done.