Spaying and neutering prior to maturity interferes with growth in dogs, just as it does in humans. Note that I didn't say it keeps them from growing tall and large -- I said that it INTERFERES w/their growth. As I said (and no, I am not going to dig out the sources & site them here as I'm far too busy for that; everyone is free to research that on their own, as I did), there is research evidence in the veterinary literature which suggests what I am saying. In addition, much human orthopaedic research is done on dogs, and these researchers know well how altering them affects their musculoskeltal development. For instance, dogs that are altered prior to maturity have greater development of their long bones. Is this a good thing? I think not, in that it throws their legs out of whack w/the rest of their skeleton. Certainly, there are other variables that influence risk of orthopaedic problems, but to suggest that elimination of sex hormones can be done without harm to the musculoskeltal system is wishful thinking. One orthopaedic medicine researcher I corresponded with told me that "too much or too little estrogen is bad for tendons & ligaments." Removal of both ovaries and uterus obviously results in the "too little estrogen" situation, making female dogs vulnerable to knee injuries in particular. Analagously, we know how vulnerable women become after menopause to osteoporosis. Is this unrelated to the loss of estrogen? There are specific estrogen receptors in the ACL of dogs (probably humans, too) -- what does that suggest? And, even if one has a dog who may be vulnerable to knee/hip injuries as the result of environmental or genetic factors, what is the wisdom in making such dogs even more vulnerable to injury by premature removal of their sex hormones? Ask any ObGyn what would happen to a girl who for some reason lost her ovaries prior to puberty. She would tell you that it would be a medical disaster for the girl, and that such a child would have to be put on hormone replacement therapy -- not so that she could one day bear children, but so that she would develop properly. The same is no doubt true for female dogs as regards loss of female sex hormones. Furthermore, particularly in females, the presence of estrogen is necessary to offset the presence of testosterone (which exists in males & females, of course, though to different degrees). Not only do I question the wisdom of lopping off a growing animal's gonads for physical reasons, I also question it from a behavioral standpoint, and suspect that it contributes to behavioral problems as well. It's all well and good to castrate cattle that the owners plan to slaughter anyway, because they don't live long enough to suffer the ill effects of loss of hormones (and if they do, who really cares?). But, to treat our dogs the same way and expect it to have no negative effects is wishful thinking driven by a political agenda (concern over pet overpopulation), and our own convenience so that we don't have to be bothered to manage intact animals. I'd be willing to bet that if a good, representative survey of dog health were done that the dogs altered prior to maturity would have far more health problems of every sort than would the intact or later-altered dogs. Of course, findings from such a study would never see the light of day because of the campaign to spay & neuter.
