I see this is an old thread, however, I would like to explain that it is becoming more and more common for vets to pediatric spay and neuter. It isn't new, but has been practiced for over 50 years. I have a 5 year old male who was neutered at 10 weeks old, and he is a healthy boy. We also have had kittens spayed and neutered at 10 weeks for 3 years with our vet now, without ever any complications. I also know of a very reputable breeder who has been early altering Persians for 15 years now, with no complications.
In my experience, the kittens bounce back quicker being spayed and neutered sooner, before the 16 week mark.
To learn more about the benefits of early spay and neuter, please check out these accredited links.
http://www.winnfelinehealth.org/health/early-spay-neuter.html
As well as a link, to report the studies of early altering, showing the health benefits.
It may be important to think about neutering your males, first as a male cat can still impregnate a cat for about a month after being neutered, so confinement away from your females will still be needed.
A female cat can also come into heat as early as 4 months of age, and a male kitten can impregnate a female by the age of 5 months. Female cats are also induced ovulators, meaning they do not have to be in heat to get pregnant.
If you would like, please contact me with your location, and I can refer you to clinics in your area who offer low cost spay and neuters. A great site that can also put you in touch with many low cost clinics is thecatsite.com, and go into the forums there. There are many helpful members that will help to do the best thing in getting these cats spayed and neutered to prevent anymore unplanned pregnancies.
