Folks with performance/working dogs have been discussing for years the wisdom of early spay/neuter in regard to the health and structural soundness of dogs (I recently weighed my options for Pinky and decided to wait). Now an an article at MSNBC raises some of the questions as many states and municipalities consider mandatory spay/neuter laws. (Thanks to Pet Connection for the link).
There are many good reasons to spay or neuter, but I think mandatory spay/neuter laws have far more downside than upside (that is, supposedly our shelters wouldn't be so full with these laws). Diane Blackman at DogPlay has a fairly comprehensive list of arguments against such laws. I personally think that the administrative costs involved with enforcing such laws would be much better spent to make it easier and cheaper for the average pet owner to spay/neuter than on the sisyphean task of enforcing laws that have been shown to be less-than effective in the long run (see this Animal Law Coalition paper, for example).
As for Pinky, I do actually plan to spay her, if for no other reason than I can't see myself dealing with the required vigilance and mess of heat cycles twice a year for something like the next 15 years (or more, I hope!). I have no interest in breeding dogs, even though I think Pinky is one awesome little dog.
I've linked to these articles before, but what the heck, I'll link to them again. So for more about the health implications of spay/neuter, see:
Early Spay-Neuter Considerations for the Canine Athlete
Long-Term Health Risks and Benefits Associated with Spay/Neuter in Dogs
Determining the optimal age for gonadectomy of dogs and cats