Funny this comes out, when only last week this research was released <a href="http://www.news.ucdavis.edu/search/news_detail.lasso?id=10498" rel="nofollow">http://www.news.ucdavis.edu/search/news_detail.lasso?id=1049...</a>
"Neutering, and the age at which a dog is neutered, may affect the animal’s risk for developing certain cancers and joint diseases"
It is also worth checking out Nathan Winograd, who is campaigning to make ALL shelters in America no-kill. It is worth looking at the statistics and reasons why shelters kill animals in their care, as most often, it is not simply that there are not enough homes.
<a href="http://www.nathanwinograd.com/?p=10627" rel="nofollow">http://www.nathanwinograd.com/?p=10627</a>