To be honest, there were always a lot of opinions on the correct timing of spay and neuter surgery, but it was mostly the veterinarians swatting away a variety of nuisance viewpoints. Armed with our cancer stats and righteous indignation over the pet overpopulation problem, we took on every challenger with the united battle cry, “Six months!!” Well, some new information has come to light, the veterinarians are in some disarray, and I am ready to stand down.

Question: When should I get my new pet fixed?

Grandpa: Not until she’s had her first litter! Important to develop her maternal instincts!

Great Grandpa: No, she needs to have a couple litters in order for your children to learn how reproduction works! How else could they possibly learn about this?

Aunt Lucy: After their first heat cycle, of course. Somebody told me that, for sure. Spay and neuter surgery makes them fat anyway. How are we supposed to deal with that? Portion control?!

Uncle Billy: That’s exactly right! No need for that surgery at all. We lost three of our last five dogs to uterus infections, but that’s just a fact of life.

Uncle Rufus: Agreed! If you get them fixed, they won’t grow real big and intimidating, and what’s the point of having a dog that isn’t even scary-looking?

Breeder: Quite right, Rufus—surgery will doom this poor animal to a lifetime of lost trophies and an embarrassingly puffy hair coat. Unremitting humiliation. That said, if this handsome pet breeds with another animal, any other animal ever, you will be in breach of contract, and I will see you in court.

Clinic Veterinarian: No, no, no. No. We have to spay is before the first heat cycle! If not, we lose our lifelong advantage over breast cancer, and that benefit is gone forever. I don’t like breast cancer, and I also don’t like removing leaky uterus infections from patients at 2AM. Especially when all of that was avoidable.

Shelter Veterinarian: No, I get where you’re coming from, but you’re not being strict enough. Three million unwanted pets were put to sleep in shelters last year, and I had to do quite a few of them. Time to spay and neuter is as soon as they are bigger than the palm of your hand!

Mathematician: Everybody, listen up. I just finished a retrospective study looking at thousands of dogs over their entire lifetime. As you know, the various breeds are predisposed to different old-age conditions, and the timing of their spay/neuter surgery might actually have an impact on that. Turns out that surgery at six months doesn’t give everybody the same advantages. Cool, right? I burned up four calculators doing that.

Clinic Veterinarian: Wait… you’re saying that I could put all the data together and come up with a specific time frame for each patient that optimizes all the health benefits of spay and neuter? And it might be different for every pet?

Mathematician: Yep. Gonna involve a lot more explaining, though.

Me: Who cares? This sounds amazing. Let’s do it!

Dr. M.S. Regan