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Should Male Dogs Be Neutered? Pros and Cons to Consider

Adrienne is a certified dog trainer and former veterinarian assistant who partners with some of the best veterinarians worldwide.

Should male dogs be neutered? Read advice from experts so you can make an informed decision for your pup.

Should male dogs be neutered? Read advice from experts so you can make an informed decision for your pup.

Should I Neuter My Male Dog?

If you own an intact male dog, you may be wondering if you should neuter or not neuter him. Welcome to the club! There are many people wondering about this debate as well. Many people have strong opinions about this procedure—both for and against.

In This Article

Today, we will look into the debate, and I will try to make this information as neutral as possible using data from the experts in the field and statistics from reputable organizations.

  • What age to neuter dogs
  • The pros and cons of neutering
  • Statistics about behavior changes after neutering
  • Trends and opinions from different people and organizations
  • Alternatives to neutering

What Age to Neuter Dogs

Depending on who you consult with, you will get different answers on the age to neuter dogs. Shelter employees and veterinarians who work alongside with shelters strongly believe in early spay and early neuter (two months of age). Breeders, on the other hand, may recommend neutering at a significantly later age. The average veterinarian may recommend to neuter at an age between what early neuter advocates suggest and what breeders suggest. So who is right? Let's see the differences and the school of thought of each.

Average Rescue Recommendation (8 Weeks Old)

Early neutering advocates push early neuter to help with the pet overpopulation problem. The belief is the earlier the pet is altered, the less chance it will have to reproduce. For instance, a rescue group may give a puppy to a new owner which signs a contract to have it neutered about two to three months later. When the time to neuter comes, the young dog escapes from the door, and bingo, impregnates the neighbor dog in standing heat. Eight puppies are born. All this could have been avoided with an early neuter, according to North Shore Animal America's Spay USA.

Early spay and neuter can be performed on a puppy as early as two months old and weighing at least two pounds. The term for this is "pediatric neuter." According to Brenda Griffin, veterinarian and Director of the Shelter Medicine Program at Auburn University School, the need for spaying and neutering dogs at six months is not supported by scientific data. Dr. Brenda Griffin supports early neuter and spay procedures and considers it to be a great way to reduce the pet overpopulation problem. Indeed, she finds it important to remind that “the biggest killer of cats and dogs in our country is shelter euthanasia."

Average Veterinarian Recommendation (6 Months Old)

Many average veterinarians still advocate getting a puppy fixed at the magic age of six months old. Because people trust their vets, most people feel this is the best for their dog. However, there are many considerations to keep in mind. For instance, there is little veterinary literature claiming what age is the optimal one for neutering. Because some dogs may reach sexual maturity before the age of six months, the practice of neutering around six months may result in males already breeding fertile females.

For effective sterilization programs, dogs should be neutered prior to the onset of puberty, explains veterinarian Ruth Marrion in the article "New Views on Neutering." Yet, the six-month-old neutering tradition lives on and there may be also risks in getting larger dogs altered this young and we will these below.

Average Breeder/Trainer Recommendation (14 Months)

If you own a large breed dog, your breeder/trainer/veterinarian may recommend to not neuter under the age of one year old. The reason for this is the concern for skeletal abnormalities common in large and giant breeds of dogs. Veterinarian Christine Zink reported concerns about the protocol of neutering and spaying before six months old in her article, "Early Spay/Neutering Considerations for the Canine Athlete."

Because sex hormones play a primary role in the closure of growth plates and bone density, the bones of dogs neutered before puberty will continue to grow. This results in "leggy specimens" characterized by longer limbs and an alteration in body proportion. This may predispose the dog to stresses on the cranial cruciate ligament. There may also be higher chances for hip dysplasia. Even more concerning is a study of 3,218 dogs which demonstrated dogs neutered before a year of age had a significantly increased chance of developing osteosarcoma.

Confused about the age when to neuter your dog? Consider your dog on an individual basis and listen to the opinion of different experts. Animal rescues and humane societies, of course, must do their best to prevent the pet overpopulation problem. Providing pets already neutered to adopters significantly reduces the problem.

The average dog owner may wish to neuter their male dog before puberty. Windmill Animal Hospital in Texas, for instance, recommends neutering at five to six months of age so to prevent the onset of testosterone-based behavior problems such as marking, mounting and aggression. Large dogs though predisposed to osteosarcoma and canine athletes would probably do best if neutered after 14 months of age.

The most important consideration to keep in mind when deciding if and at what age to neuter a dog is to consider all the health and disease information on an individual basis. The dog's age, breed, genetic history, predisposition to disease, prospective housing and training of the animal should all be considered for an informed decision.

The Pros and Cons of Neutering Dogs

Will neutering reduce aggressive behavior? Will it prevent or reduce urine marking? Will there be health benefits? Will it hurt the dog? Are there risks? Let's look a bit at the pros and cons of neutering dogs so to make an informed decision.

Health Pros and Cons

We have all heard that neutering a male dog provides countless health benefits, such as reducing prostate and testicular cancer, but how true is that? While it is true that with no testicles, the chances for testicular cancer in a neutered dog are close to nil (unless there is a retained testicle in the abdomen) there are other important considerations. Veterinary oncologist Kevin Hahn, admits that there are higher incidences of testicular cancer in intact animals but neutered dogs are predisposed to a four times greater risk for prostate cancer and a one and a half to three times greater chance for developing bladder cancer.

Laura J. Sanborn, which has reviewed extensive veterinary medical literature on the topic argues that the health risks derived from neutering may actually exceed the benefits. Her research paper is surely worth reading as it may be an eye-opener. So what are the health benefits of neutering male dogs? Laura lists the following three while she lists nine health conditions brought on by neutering!

The Health Benefits of Neutering

  • Reduced risk (
  • Reduced risk for non-cancerous prostate conditions (ie benign prostate hyperplasia)
  • Reduced risk for perianal fistulas

The Health Risks of Neutering

  • Increased risk for osteosarcoma (bone cancer) when neutered before one year of age
  • Increased risk for cardiac hemangiosarcoma
  • Increased risk for hypothyroidism
  • Increased risk for progressive geriatric cognitive impairment
  • Increased risk for obesity
  • Increased risk for prostate cancer
  • Increased risk for urinary tract cancers
  • Increased risk for orthopedic disorders
  • Increased risk for adverse reactions to vaccinations

Behavioral Pros and Cons

There is a belief that neutering reduces certain unwanted behaviors. According to veterinarian Wendy C. Brooks the only behavior changes that are noticed after neutering are mainly those influenced by male hormones. Roaming in search of a mate, fighting against other male dogs to compete for a mate, sexual behavior and marking territory to claim territory and potential mates are some examples of behaviors that may be reduced. Protectiveness of the home and family is not something that goes away by neutering, according to the ASPCA.

When it comes to aggression towards other dogs, it may reduce if it stems from a hormonal drive to compete for a mate. However, it is important to consider that aggression is also often based on fear and it also has a learned behavior component, where the dog practices it because it has been repeatedly reinforced over time by seeing the other dog back off.

Before neutering in hopes of reducing inter-dog aggression, a behavior expert should be consulted to determine the exact cause of the aggression. In many cases, a behavior modification program may be all that it is necessary, to get the situation under control.

According to the ASPCA, intact male dogs can be a target for aggressive behaviors from other dogs. Indeed, other male dogs may detect an intact dog's high testosterone levels which may make him a target by other male dogs.

Neutering a male dog that has manifested aggression towards humans in the household or strangers will generally not help since these are mostly fear-based in the case of dealing with strangers or sometimes caused by lack of structure and leadership in the case of aggression towards humans in the household. However, it is also true that intact male dogs are more prone to react quicker and more intensely and for a longer period of time to certain stimuli. This is due to testosterone acting as a behavior modulator, according to Milford Animal Hospital.

Behavior Changes After Neutering

Often, dog owners get a better grasp of things by looking at numbers. While these statistics may be encouraging, it is important to take them with a grain of salt. Each dog is an individual, and as so, should be treated on a case by case basis. There are ultimately no guarantees your dog will change certain behaviors after being neutered.

  • "Neutering decreases aggression in 62% of inter-dog aggression between male dogs" (Hopkins et. al., 1976)
  • Neutering reduces roaming in 90 percent of males, according to Dr. Nicholas Dodman.
  • Neutering reduces competitive aggression between males in 60 percent of males.
  • Neutering reduces urine marking in 50 percent of males.
  • Neutering reduces mounting in 67 percent of males.
  • Neutering overall reduced or eliminated behavioral problems with 74 percent of the male dogs showing improvement according to a study by Heidenberger and Unshelm. However, Dr. Milani a veterinarian and author of several books on on canine health and behavior, dissents on this claiming that the great majority of aggressive dogs she treats are already sterilized. She believes that a “placebo effect" takes place where dog owners relax more knowing that their dog has been neutered. This, in doctor Milani's opinion, takes the pressure off the dog causing the behavior to improve.

So should you neuter your dog or not? In many cases, the choice is inevitable, breeders may have had you sign a neuter contract or your town may be soon requiring spay and neuter programs. You may also be tired of having to keep your dog at bay near females in heat and may have had several people complain about keeping your dog intact. While an intact male on a secluded farm in the middle of nowhere may not cause many problems, an intact male escaping to impregnate female dogs is a big problem in today's society. Numbers in this case may also help evaluate the extent of the problem:

  • In six years, just one female dog and its offspring are capable of generating 67,000 puppies!
  • About 70,000 puppies and kittens are born every day in the USA. At the same time, 10,000 humans are born. It is crystal clear there are not enough homes for these precious pets!
  • Sadly, 8,000,000 dogs and cats are euthanized each year.

What Myrna Milani claims goes a long way “When all of the responsible people neuter their dogs, who’s left breeding?” she asks, answering, “The irresponsible ones.”

Truth is, failure to neuter requires a great deal of responsibility for dog owners. A great amount of commitment is required to provide close supervision and responsibility. Sadly, this is something that many dog owners do want to endure. This is perhaps why people are so fast to look for quick solutions such as electronic collars, crates, and harsh board and train programs.

People do not have time or the will to be responsible dog owners and this comes at the dog's price. Veterinarian Patty Olson explains: "One reason sterilization is so popular in the United States is that few owners can claim that level of care." She adds:

"In Sweden, 93 percent of dogs are intact, they don’t neuter. They have some pretty amazing ordinances by which dogs are controlled, there are very significant fines, and they do seem to have more responsibility. What we’ve had to do in the U.S. was institute something because of, if you will, irresponsibility.”

This is quite an interesting take on the pet overpopulation problem.

According to the ASPCA in regards to neutering "it is important to realize that the potential drawbacks of neutering are minimal relative to the benefits".

According to the AVMA "Although spay/neuter is an important part of effective population control programs, and may benefit individual dogs and cats if performed at the appropriate time, whether and when to spay/neuter specific animals requires the application of science and professional judgment to ensure the best outcome for veterinary patients and their owners."

So should you neuter your dog or not? You now may be more confused than ever. Neutering, in most cases, is an elective procedure, meaning that it is ultimately your choice. However, unfortunately, as seen, there is no easy answer to the decision. The fact that there are risks in neutering cannot be denied, however, the pet overpopulation problem cannot be ignored. If you choose to neuter, make an informed decision on the best time to neuter, and if you choose to not neuter, you will have to consider the need to be hyper-vigilant all the time and never, repeat never, allow your dog to escape and have access to a female in heat.

Seeking Professional Advice

If your dog is exhibiting behavioral problems, consult with a dog behaviorist. If you are considering neutering or not neutering your dog, do extensive research on the topic. There are many considerations to keep in mind. This article does not cover all considerations that ultimately vary from one dog to another.

Alternatives to Neutering

For those who elect not to neuter, are there any alternatives? Chemical castration using Neutersol was produced in 2003 but it was pulled off the shelves two years later. Esterilsol is now being manufactured by Ark Sciences, LLC and its anticipated to be launched in the second quarter of 2012. Of course, in this case, several considerations about side effects and health benefits/risks need to be assessed.

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

Questions & Answers

Question: I haven’t really seen any demonstrations of aggression, roaming, or humping in my dog. However, marking in the house is still an issue on a weekly basis. To me having to address that twice a week in our concrete basement isn’t the end of the world, but my significant other feels strongly otherwise. That said, of course, I don’t want my dog to be marking! What behavioral training tips may I try in order to dissuade my dog from marking?

Answer: Dogs who mark need to be supervised so that they can be redirected and escorted outdoors where they are praised and rewarded for eliminating there. Supervision is a must. Soiled areas in the basement should be cleaned with enzyme-based cleaners so to remove the smell and traces of urine. Some dog owners use belly bands for the issue, especially for those cases where the dogs cannot be always supervised.

© 2012 Adrienne Farricelli


Art Scureman on March 10, 2020:

We lost our 8 year old German Shepherd ,neutered at five months,ro bone cancer of the spine. Prior to bone cancer he had prostate cancer, two torn ACL's and to top it off bladder cancer which required reconstructive surgery. We also had obesity issues although he only ate four cups of kibble a day.

We now have a nineteen month old West German Shepherd and have decided not to neuter .He has a fabulous disposition, extremely obedient, does not mark inside and overall is a wonderful member of the family (7 grandchildren ).He do need to feed him limited ingredient dog food as his stomach does not handle chicken or beef well so he is on a lamb diet .He has a great deal of energy, reacts well with other intact males except if one try's to dominate him then he will react. For now our decision is not to neuter as we believe many of the health problems from our prior GSD were due to early neutering.

Thomas W Hickman on September 02, 2019:

My dogs name is Bear he is a Labernese about 110 lbs and will be 2 years old in 2 month. He is very good with people, dogs, & cats, his only problem is with aggressive dogs he will go after any big dog that show aggression. I have researched the whole thing of neutering or not neutering and have decided to keep him in tack, I am responsible and do not let him run lose and the few time I do let him run he always comes back when I blow my whistle 2 time, I trained him to come back when he hears the 2 whistles. Today on our walk he meat a German Shepard that he was friend with when he was a year old and they were good together but today this Shepard growled at him and he went after the Shepard but I had him leashed and was able to keep him from getting the Shepard, both dogs are male and in tact. I think it is because both are in tack and more apt to fight because of this. I would appreciate any thoughts on this behavior. Thanks..

Imani Williams on February 12, 2019:

Greg Schweizer

I don't really understand where you drew that conclusion. Can you explain to me how you got there? As far as I know, neutering or not neutering a dog may or may not affect the health of a dog, but whether or not they are bred has absolutely nothing to do with it.

Destiny on August 04, 2018:

My boyfriend and I took in his father's dog because he wasn't caring for him properly and wanted to take him to someone he barely knows across the country. He is a 2.5y/o intact shepadoodle, he's dog aggressive and not barks at strangers but is nice and wants attention when they approach him. Once we got him, he started acting different and had problems with his bowel movements, my boss (a vet) said that he has a enlarged prostate, and that it should go away with him getting neutered. He said there is a 10% chance it won't go away, but we're not worrying about that at the moment. Just hoping that after he's neutered he'll be less dog aggressive and that the prostate will shrink back a bit. I believe you should neuter your dogs after they're a year old AT LEAST if they're not being used for reputable breeding. His dad got him from a very good breeder so we highly doubt it's anything cancerous, but it could've easily been avoided if his dad got him fixed, so now we're going to do it hoping it helps.

Lucy on May 21, 2018:

I just adopted a less than 1yr pit bull male. I want him neutered but my husband is against it. All my dogs have been females and neutered. Will I be making a mistake if I give in to my husband and NOT neuter him??

Michelle Doan on October 02, 2017:

I know this is an old comment but hopefully someone will reply. I just had my 2 year old male german shephard neutered. He had issues with his scrotum swelling. It's the size of a grapefruit. It's been 2 weeks and its still swollen. Now it seems to be oozing from the incision spot. I'm taking him to the vet tmrw. Have you ever had this happen and if so do you have any recommendations for quick healing?

Greg Schweizer from Corona, California. on August 13, 2017:

Freda, if you don't neuter him make sure you breed him. I mage that mistake. It does catch with them.

Freda Stevens on August 12, 2017:

That article was very helpful on Neutering, it helped me to make a decision, and that is not to neuter my 2 year old schnauder, terrier mix dog. Thanks so much!!

Adrienne Farricelli (author) on May 03, 2013:

Well neutering may well take care of the roaming in search of a mate but not other types of roaming such as looking for food, company and just the adventure, but it's really up to you on considering how much of his behavior you are willing to handle. At this moment, your dog is still able to breed with a female but as you may know he can't produce sperm to cause pregnancy. So yes, you're left with a dilemma, but it all boils down on responsible ownership and how much effort you are willing to put in preventing him from roaming. Here is an interesting study:

TimH on May 02, 2013:

I have a 13 month old Rohdesian Ridgeback who had a vasectomy when he was 14 weeks old. He has a mellow personality, shows no aggression, but does have a tendency to roam (so is generally kept on a leash when other dogs are encountered on our daily runs).

So the dilemma ... to neuter or not ?

I also have a 14 year old OES who was neutered at 8 months and has significant ligament issues in his advanced age, so am reluctant.

Any advice ?

Adrienne Farricelli (author) on July 12, 2012:

Bmd, I do have to agree that neutering a dog for the simple fact of reducing the pet population problem is quite an extreme measure. Problem is, people often want a dog but often do not want the responsibility of dealing with problems. In this case, the dog is better off altered, but of course, if there were less invasive options, I think that would be much preferable. I admire the people in Sweden. In Sweden, 93 percent of dogs are intact, they don’t neuter. But this is also because they have some pretty amazing ordinances by which dogs are controlled, there are very significant fines, and they do seem to have more responsibility. You sound like a responsible owner as well, and in that case, yes, I agree in keeping the animal not altered. I appreciate your thoughts on this and best to you too!

BmD on July 12, 2012:

this is good thanks alexadry

although some of the statistical information fails to indicate the quality of the breeding of any given individual animal. This also is an issue I have in my researches.

unfortunately some statistical information would be a percentage of animals whom never get to see the vet again in their life as they are more of a garden accessory, they are given food and water but the owners really pay no attention to the animal they have so any changes or problems are never included under any statistical studies.

The other problem associated with the statistical information is generated by a large percentage factor of poor breeding

I will reference one of the replies of a dog owner who decided not to neuter and the dog ended up with cancer. I could be most certain a higher percentage of cases will be mixed breed or backyard breed or puppy mill dogs.

I have at present 6 intact dogs all are healthy 5 are female 1 is male, I have had many intact male dogs here with the bitches and never have I had unwanted litters .. I have never had any pregnant bitches in my care either ...

I believe if your dog is the cause of an unwanted litter or your bitch gets pregnant with out your knowledge or with out you wanting her to become pregnant then your not as responsible owner as you think.

population control is easy, I see by both your posts alexadry that your devoted to this problem. I understand why please be advised I made a typo in my other response to you I failed to pick it up as I was in a hurry.

responsibilities of pet ownership to any individual pet owner should be to take care of your animals as best to your ability physically and as far financially as is possible or viable.

remembering as the owner it was your choice to bring the animal into your home. Also keeping in mind if you had all your choices made for you how would you feel.

I for one would not opt for castration just to help control the plague proportions of the human entity so I would not have such a radical procedure done to an animal. There are alternatives to the spay neuter which I had indicated else where which are also just as effective in population control.

the cemical casteration is available in Australia as is Tubal Ligation and vasectomy . they are also available in America though I'm not sure what states this information would be available by a local vet or googleing veterinary reproductive specialist for your area.

(note to general public to web search these terms if you're wondering what tubal ligation and vasectomy are)

for now I think I'm done on this subject I find it frustrating

I will check for your response if you do respond, I may not reply again.

thanks for the debate and all the best to you Alexadry



Adrienne Farricelli (author) on March 12, 2012:

Thank you, chemical castration was actually on the market a while back but it looks like it going to be available again soon.

Simone Haruko Smith from San Francisco on March 12, 2012:

Wow, so much useful information here! Great Hub.

I had no idea that dogs may soon be chemically neutered. That's quite interesting! Thanks for the interesting and informative Hub.

Greg Schweizer from Corona, California. on March 11, 2012:

Hi Alexa, I just want to share my experience with this. I rescued a do at 8 weeks old, named him Lonesome. He had such a great temperment and was so smart that I decided to eat the $60 dollars I was supposed to get back when I had him neutered and had all intentions to find a similar dog to mate him with. Well that never happened. When he was 9 years old he came down with hormonal tumors around his rear area. The vet told me these came about because he was never neutered and never mated. I had those surgically removed, but they had spread to his internal organs. At age 11 he had deteriated so bad I elected to put him to sleep. He got so bad I couldn't stand to see him suffer. I believe in neutering now. I had my Harley neutered when he was 6 months old. That's just my experience to share. Greg

Suhail Zubaid aka Clark Kent from Mississauga, ON on March 11, 2012:

A great hub and just in time for me to decide. My Kuvasz boy is almost the age where a decision needs to be made.

bilghi from Samsun, Turkey on March 11, 2012:

Great hub. It's been very useful.. :)

Dragonrain on March 10, 2012:

Great hub :) So many people advocate spaying/neutering for population control without knowing the potential cons of neutering. It takes a very dedicated owner to keep an intact dog and be able to ensure that it doesn't contribute to the pet population, but it can be done.

Jessica Rangel from Lancaster, CA on March 10, 2012:

This was a great written hub! I've never thought about this topic much. I have a female dog, and I am thinking about getting her fixed, but I worry about what that is going to do to her body.

There are a lot of great facts on this hub! I'm so glad I read it! I'm definitely making an appointment with the Vet next week!