Thursday, December 3, 2009

Ask Billy: When Should I Neuter My Male Dog?

Jamie and her Portuguese Water Dog Oscar wrote in and posed an important question about neutering:

I have a 5 month old Portie named Oscar. I am getting conflicting advice as to when is the best time to neuter him, which I absolutely am going to do.

My parents who have Oscar's older brother (5 years old now) had him neutered at 7 months. My vet says anytime now is okay to be neutered. However, the confusion is that Oscar's breeder asked me when I picked him up to wait until he's at least 18 months old.

My parent's dog is in perfect health so maybe they have the right answer. My vet is an expert in neutering so maybe she has the right answer. Finally, the person who breeds the dog and is the expert in Porties might have the right answer. What do you recommend and what are the pro’s and cons of all the choices?

Jamie, thank you so much for your question. Neutering often brings up a wide variety of opinions, especially when people have different, but equally valid viewpoints.

Let's start with what happens when your dog is neutered. (You may want to have Oscar leave the room.) The veterinarian will examine and sedate your pooch and then surgically remove his testicles from the scrotum. The scrotum (aka "sac"), however, remains and eventually shrinks to a barely noticeable size.

Jamie, I applaud your commitment to neutering Oscar and helping the animal community. Unfortunately, millions of healthy unwanted dogs and cats are euthanized each year in the United States alone. Quite simply, a neutered male (or spayed female) cannot make puppies and, therefore, won’t be adding to the pet overpopulation problem.

Breeder's perspective:
In addition, to finding qualified homes for their puppies, reputable breeders are typically interested in breeding for specific attributes and finding the next Top Dog Model – meaning they want to find show quality dogs.

Once a dog is about 18 months old, he's fully mature. Accordingly, a breeder (or anyone for that matter) can reliably assess the dog for show qualities, such as bite, coat, structural soundness and temperament. If a dog is neutered before he's at least 18 months, you can't reliably guage what he’ll be like as an adult. Just as it’s impossible to look at a 7 year old girl and determine if she’ll grow up to be a supermodel, we can’t look at a male pooch under 18 months old and determine if he’ll win Best in Show. Moreover, a neutered or spayed dog cannot compete in the show ring.

Although I don't know Oscar's breeder, he or she may be recommending you wait to neuter him so he can be assessed to determine if he qualifies as a show or stud dog. In addition, some people believe that a dog doesn't fully physically mature until he reaches a certain age. Interestingly, the American Animal Hospital Association reports that genetics, not hormones, are the primary factor in determining size:

Neutering does dramatically reduce the amount of testosterone in a male pup's system, which may give him a bit less muscle mass in the long run, but won't affect his height or the size of his frame. Actually, studies have shown that dogs spayed or neutered early (at 16 weeks or younger) tend to be slighter larger than those altered later in life.
Neuter A Pet Early
If Oscar is going to be a pet, there’s no need to wait and see if he'll be qualified for the show ring. Therefore, I agree with your parents, your veterinarian and most experts and recommend neutering Oscar as soon as possible after he's 5 months old. I say the earlier the better so Oscar (or any male) has no opportunity to develop any bad habits associated with testosterone, a powerful male sex hormone.

When a dog is neutered before he sexually matures at about 6-9 months, he’s much less likely to develop the annoying and dangerous behavioral habits associated with romance and testosterone. Contrary to myth, neutering is unlikely to affect your dog’s playfulness, interest in work, friendliness or personality. Obedience training, therefore, remains important whether or not a dog is neutered (or spayed).

How is Neutering Beneficial? Let Me Count The Ways....
Neutered dogs typically live longer than intact males because there’s no testosterone urging Fido to search out females for romance. While roaming, your dog is more likely to be hit by a car, be attacked by another dog or animal, be stolen or encounter many other dangers, like poisoning or disease.

Likewise, because neutered Fido no longer has the strong desire for romance, he’s less likely to mark his territory to advertise for mates. Thus, he's much less likely to urinate in your house or yard or on every single tree encountered during a walk. Although the evidence isn’t conclusive, loads of research has shown that intact dogs are more aggressive because high testosterone levels may cause them to fight over females.

Moreover, an intact male is a target for other males, even those who are neutered. Males can detect the high testosterone levels in an intact dog and dominance challenges often result. Even Arthur, my neutered Cocker Spaniel who is normally the world’s most gentle dog, bears his teeth when he sees or smells an intact male anywhere near by.

Neutering Offers Many Health Benefits
Testicular cancer in older dogs is a significant life-threatening possibility. By removing the stuff inside the scrotum, the risk of testicular cancer is eliminated.

Neutering cannot totally protect a dog from prostate cancer or other prostate problems. Neutering, however, does significantly decrease the risk of prostate enlargement or infection and reduce urinary problems in later life. In addition, a neutered male is less likely to suffer from testosterone-related health issues like testicular tumors and certain hernias.

Always Talk To Your Vet
Neutering is a medical procedure and, like all medical procedures, carries some risks. Indeed, neutering is no guarantee that any behavioral problem will be eliminated since Fido will still have some testosterone coursing through his veins. (Please note, after the procedure, it may takes a few months for Fido's testosterone levels to subside.) Bottom line: Because testosterone levels are significantly reduced, many people find a neutered dog more manageable.

The benefits of neutering far, far outweigh any risks or cons. Always discuss the pros and cons of neutering for your individual dog with your vet.

Finding Free Or Low Cost Spay And Neuter Clinics
Communities around the country offer free or low cost spay and neuter clinics. Check with local animal shelters for more information. Find local clinics here:


For More Information
Check out American Humane's article on how spaying and neutering affects our furry friends and our community. Look at these articles too:

ASPCA: 10 Top Reasons to Spay or Neuter Your Pet
American Animal Hospital Association: Neutering Your Pet

Neither Billy nor Jill is a veterinarian. As with any medical procedure, always consult with your vet before making any decisions.


  1. Our dog was already neutered before we got him from the animal rescue centre. I know that a lot of people claim that neutered digs can#t fully develop and that it is not good for their psyche.
    Well, I have hardly met a healthier and happier dog than Tom. We can take him everywhere and he is ever so good with other dogs,regardless of whether they are male or female.
    And there is perhaps one more aspect for those people who feel sorry for castrated dogs:
    Imagine, you were confronted with lots of nice women but never allowed to go out with one, let alone get between the sheets with her. Would taht make you hppy?
    Ok, people are not dogs but for a dog it is certainly highly unpelasant if it is denied its right to sexuality (when still intact.) On the other hand, a neutered dog can lead a happy life. So think about it.

  2. I recently came across your blog and have been reading along. I thought I would leave my first comment. I don't know what to say except that I have enjoyed reading. Nice blog. I will keep visiting this blog very often.


  3. My wife and I are committed to neutering our golden retriever pup, but we'd struggled a bit about *when* to neuter him. Our vet recommended neutering him at 6 months, but several breeders recommended waiting until 18 months.

    The breeders' recommendations were based on a relatively recent study that suggests that neutering a dog before it's full grown can lead to relatively worse health consequences for the dog. Below, I've pasted a link to a study that I believe is the study that the breeders were referencing. I'm hoping that it helps someone.

    (Of course, the factors that are addressed in this study are not necessarily the only factors that are involved in the decision. Behavioral concerns might also be a bigger concern for some dog owners. The author of the study recognizes this.)