Dog and Cat Lifespan and spay/castration

I have a professional and academic interest in spay/castration for dogs and cats, and have read extensively on the subject.  Obviously, we do a fair bit of it in the practice, and I taught spay/castration at Penn full-time for seven years.  So it’s not just part of the job for me–I want to know how to optimize the procedure (small wounds, lots of pain control, short surgical times, good process), optimize the benefits (when is the best time to do in in a dog’s career), and understand any negative effects.  While the advantages for spay (female surgical sterilization) for dogs and cats is unequivocal (so clearly advantageous as to be beyond reasonable debate) and the advantages for male cat surgical sterilization–castration–was similarly overwhelming, the case with male dogs was less clear.  There were some likely behavioral advantages, there were some diminished health risks, but there was more limited data.  When asked by owners, I would describe my bias as being pro-surgery, but that I lacked data to show why I believed in that approach.  Until now.

In the same issue of the Journal of the American Veterinary Medical Association, there was mention of two independent studies looking at (among other things) longevity of pets.  One by the Banfield group of veterinary hospitals found that spayed and castrated dogs and cats live significantly longer than their un-spayed/castrated counterparts.  Another study looked at dog patients in veterinary teaching hospitals and found that castrated males lived (on average) 13.8% longer than intact (not castrated) dogs, and that the benefit for female dogs is even greater–26.3% longer lived if spayed vs. intact!  That is more than a year for males and can be several extra years for females.  Wow!  Both of these studies were quite large numbers across many breed types, and their findings are in alignment with respect to a consistent magnitude and direction of the benefit (in the Banfield study, castrated male dogs did even better, at 18% longer lived vs. intact).

This is great news for pet owners who have followed our advice to spay and castrate all these years–you can credit those procedures for tacking on an additional 1 or 2 years to your pet’s life.  Give yourself a nice big pat on the head from your dog or cat for that.

(I’d provide a link right here, but WordPress has decided to become slightly difficult–the “insert link” radio button is inactive, and numerous repair suggestions have failed to restore it to functionality.  There is a link just to the right titled “Banfield State of Pet Health 2013″.  Lifespan and Cause of Death link is the other study referenced).


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