As promised, the results of the research on the question posed on Sunday:

Should vets reconsider vasectomy for male dogs instead of neutering (castration)?

This subject turned out to be very complex but limiting my links to five helped me narrow its scope somewhat. So did not trying to master all the medical literature.

Note: Most of the articles deal with spaying as well as neutering. You can skip the girly parts.

The background

Everyone can agree that keeping dogs from reproducing at will makes the world a better place for both animals and people. And, for a long time, it’s been common wisdom that neutering  confers health benefits as well as karmic ones. But recent studies have linked a lack of testosterone with health problems in male dogs.  Is it time to consider vasectomy, which would offer effective birth control without the side effects?

Pros and cons of neutering

Benefits, the informational wing of the Foster & Smith pet products site, offers the standard case for neutering (1), both from a health and behavioral perspective.


Several potential downsides of neutering are detailed in this piece (2) by Alice Villalobos, DVM, in Veterinary Practice News.

The case for vasectomy

Blogging at the PetMd site Fully Vetted, Patty Khuly, DVM, argues for the partial snip (3).


  • The above-cited studies on neutering-related medical problems either took issue with the procedure when performed too early or didn’t determine the age at which health was impacted.
  • According to this summary of long-term scientific studies (4) in The Association of Animal Behavior, there is no correlation between the age of neutering and behavioral benefits, so it will be as effective (or not) if neutering is done at a later — and theoretically safer to the health — age.
  • Testosterone-inspired behavior such as aggression, marking, and roaming are among the main reasons male dogs end up in shelters.
  • Vasectomies would not reduce such behaviors.
  • Subjecting dogs that develop aggression problems to a second surgery later on is not desirable from either a medical or financial perspective.
  • Because vasectomy is not widespread, no studies have been done on potential health problems with the procedure as have been done with neutering.


More study needs to be done on the best age for neutering, but until nonsurgical sterilization (5) becomes a common practice, castration is still the best option, not the surgical middle ground offered by vasectomy.

Thanks to  Kenzo_HW on Twitter and Roxanne Hawn for providing me with links to the Fully Vetted and Alliance for Contraception in Cats and Dogs sites, respectively.

Thoughts? Ideas for my next topic?

18 thoughts on “The Friday Five: Vasectomy vs Neutering”

  1. Pingback: Tweets that mention The Friday Five: Vasectomy vs Neutering --
  2. It seems to me what’s missing is the case against neutering at 6 months of age or later? #2 is about the risks of early neutering more than anything else, while #3 fails to make a compelling argument, IMO.

    1. Yes, you’re right, I could find no definitive research — i.e., on a large scale, over an extended period of time — that determined there was a problem with neutering after six months or later. As I mention later, the studies were either based on neutering before six months or didn’t divide the sample by age.

  3. Future topic: weird skin growths? Whether to attend to them? I ask only because Archie has a plethora of small fatty tumors. Now he’s developed what seem like minuscule warts. And he has a couple of bumps that I think may be the remains of broken off ticks from back when he used to go hiking. Gross topic, but would be useful for me, at least.

    1. My sense is that those growths are pretty common among older dogs and that almost all the are benign. Since you’ve been taking Archie to the vet regularly, I’m sure she would have alerted you to any problems. But it’s an interesting topic, and I’ll see if there’s any good information.

  4. I love your idea of posting a question for inquiry and Sunday and the results on Friday. What I’m wondering is what’s the backstory for this week’s topic — fixing male dogs 🙂

    1. Thank, Deborah. It’ll be an interesting experiment — it took a LOT of time, but I ended up with an opinion different from what I thought I might have.

      As for the backstory… I’ll never tell! 😉

  5. If this is an example of your Friday Five series, I think you’ve got something. We had both Ty and Buster neutered … Ty at 6 months and Buster at 12 months (when we rescued him).

    Idea for next topic. Why do people who have no plans on showing their purebred still have their dogs ears and tails docked? Is this cruel and unusual? Unnecessary? Expensive? All of the above? Or don’t the dogs care?

    Have a great weekend!

    1. Thanks, Rod. Six and 12 months seem ideal ages for neutering — not too early, not too late (although apparently there is no “too late”).

      I like your idea but I’d have to find articles that defend the ear and tail docking for dogs — and I don’t think I’m going to find any. But I’ll check.

  6. I think that the benefits of spaying/neutering a dog far outweigh the possible health consequences. Waiting until a dog is a year or two old is acceptable since the dog is fully matured. As for a vasectomy, I really don’t see a point to it. Intact male dogs are just plain annoying even if they can’t produce puppies.

    1. That’s the best summation of the research, ever: “Intact male dogs are just plain annoying”!

  7. Love an update. I have a female that was kinda spay at 6months and they missed an ovary. She kept her young girlish figure until this year. She 11 years old and getting really gray ol’ lady. She never gain the spay weight or had urine leakage problems. She would cycle but never true heat. Just an idea.
    I now have gaint breed male and am studying the idea.

  8. To default to castration is absurd. Why not try the vasectomy until it is apparent it doesn’t work? Are we so arrogant that we chop off our dogs balls out of a simplistic, yet ritualistict, belief that it will make the dog ‘less of a man’ and therefor more docile. If he did not have to eat we would stitch his mouth shut to stop him from barking.

  9. “•Testosterone-inspired behavior such as aggression, marking, and roaming are among the main reasons male dogs end up in shelters.”

    False. The main reasons male dogs, or female dogs, end up in shelters are irresponsible ownership, misguided or inadequate puppy training (and lack of follow-up training and socialization in a dog’s first year), and a general cultural canine illiteracy as to how to produce a well-balanced dog.

    Moreover, “testosterone-inspired behavior” is a meaningless and misleading term, as no dog in its natural state of hormonal intactness presents an inherent problem. How a dog is understood by humans and how it interacts with humans are the behaviorally dispositive factors here.

    Moreover, “aggression” is not a product of testosterone but instead, in the vast majority of cases, an ontogenesis of fear, which in turn arises from misguided or inadequate socialization and training and the absence of a basic structure of life in concert with a human a dog understands.

    “Aggressive” dogs who are neutered do not become less aggressive as a result of surgery.

    Surgery can and does change collateral behaviors but it does not address basic behavioral characteristics.

    Evidence is increasing that such radical surgery for dogs at young ages is more harmful that first thought; the conventional wisdom needs serious re-examination.

    1. You’re absolutely right. I wrote this post quite a long time ago. I’ve read a lot and changed my position since then. Thanks for coming by with your helpful comment. I can’t go back and update all my posts, but I do appreciate when someone else does.

      1. Thanks for the generous response. My thinking on this subject has changed a lot too over the years, so I sympathize.

    2. I got my dog from the shelter last summer. He was 1-3 yrs old maybe even younger. I feel lucky because they actually gave him a vasectomy. I don’t know how common this is as far as I can tell it’s hard to convince a vet to do this. He’s a Boston terrior mix, probably some Jack Russell. He’s super loyal, obedient, smart, loving. He gets along with other dogs. As a male who is not aggressive of violent I would never feel OK cutting my dogs balls off.

Leave a Reply

Your email address will not be published. Required fields are marked *