I find this article to be rather interesting. It explains the risks and benfits of neutering/spaying your dog.
http://www.naiaonline.org/pdfs/LongTermHealthEffectsOfSpayNeuterInDogs.pdf
Some of the things they listed are quite simliar to the things some women experince after having an oophorectomy (removal of the ovaries). Women after having an oophorectomy they experince simliar effects of menopause. Spaying a female dog you are removing the ovaries and the uterus.
http://en.wikipedia.org/wiki/Oophorectomy
http://www.medicinenet.com/menopause/page3.htm
Same for human males who have had an orchiectomy due to medicial problems such as testicular cancer that was required to have their testes removed.
http://www.webmd.com/cancer/radical-inguinal-orchiectomy-for-testicular-cancer
If it happens in humans, I don’t see why it wouldn’t happen in dogs. Although, I do believe people need to be responsible for the care of their animal. It is your choice whether you wish to alter your pet.
