Because of my reading in early spaying and neutering, I have put in my contract that this will be completed after 18 months of age, at the very youngest.  Preferably much older.  My ultimate concern is the health of our puppies, and although the benefits of  early sterilization may appeal to some, the risks far outweigh the benefits, as cancer rates increase such as lymphosarcoma and hemangiosarcoma, torn ACL's and improper bone growth are typical without reaching full adulthood with proper hormones.  Bones can grow elongated and cause joint pain and create dysplasia, even in the absence of genetics for dysplasia.   Most of these health concerns are non-existent if you wait until  FULL maturity to spay/neuter, or consider a tubal ligation or vasectomy. Please take the time to research the evidence-based studies on early sterilization.   Let's look at common sense, spaying is removing the entire reproductive system in a female, including her ovaries.  Neutering is castration in a male.  At six months of age, they are not fully grown and we certainly would not do that to a human at all, let alone the equivalent age in our how can we think this is healthy for a dog.  Whenever humans step in and change the course of nature, we never know the result.  Please read for yourself and click the links to see the articles, two of which are sponsored by the American Kennel Club, your AKC registered organization for your puppy.

When To Neuter:  An evidence-based look at the pros and cons of early sterilization

Find the original article at:  http://viewer/

Now that your new puppy is settling nicely into his new home, you'll probably be checking your list of puppy needs for the near future.  If your pup isn't already neutered or spayed, you must decide whether he'll be sterilized.  Once you decide, you'll likely wonder when the best time would be to have the procedure done.  There's probably no better subject for our first column on evidence-based canine health care than the benefits and risks of early-age sterilization.  Evidence-based medicine for dogs, as well as people, involved making health decisions based on the best, most up-to-date scientific research in addition to their doctor's opinions and experiences.  There's a wealth of expert opinions, but research into the health effects of early-age sterilization is harder to come by.

Spaying (the surgical removal of a female's uterus and ovaries) and castration (the removal of a male dog's testicles) are necessary for decreasing the population of unwanted animals in shelters and rescues.  Neutering, however, deprives dogs of sex hormones that have many effects on their health, some beneficial and some not.

Veterinarians know a lot more now about the health benefits and risks of neutering than they did a decade ago.  They used to think removing a dog's testicles could help protect him from prostate cancer.  We now know it doesn't.  In fact, neutered dogs are two to four times more likely to develop the usually fatal cancer than intact dogs.  Castration does eliminate the risk of testicular cancer and other prostate problems, but these are not as deadly as prostate cancer.  Although spaying prevents uterine infections and ovarian cancer, it increases the risk of urinary incontinence.  Because early-age neutering has only recently become widespread, we have few studies to show us its risks and benefits.  These studies show neutering at an earlier age reduces surgical complications as well as the dog's recovery time from anesthesia and surgery.  And they confirm that spaying a female before she is sexually mature substantially lowers her risk for mammary cancer-the most common, often fatal cancer in dogs.  They also show neutering dogs before they mature may increase certain risks.  For example, depriving growing dogs of sex hormones can allow some bones to grow longer than they normally would.  This can place unhealthy stress on parts of their skeleton, especially in larger breeds.  Dogs neutered before maturity are at increased risk of hip dysplasia, of rupturing the anterior cruciate ligaments (ACL) in their knees, and some other skeletal problems, which can lead to disability, chronic pain, and large veterinary bills.  And they are at greater risk for bone cancer.  People often cite the benefits of neutering on dog behavior as another reason to neuter early, but studies show the effects of neutering on aggression varies so greatly among breeds that no generalization can be made at this time.


The risks and benefits of neutering are not the same for all dogs, which is why most experts agree that the dogs sex , age, breed, health conditions, temperament, and activities must be considered when deciding to neuter.  Humane organizations neuter puppies before offering them for adoption to reduce the need to euthanize unwanted animals.  But when deciding on  neutering an individual pet, population control should be a less important concern than the health of that animal the American College of Theriogenologists says.  Neutering has health benefits and risks, and both should be considered, Herris Maxwell, DVM says.   Maxwell is a diplomate of the college, which provides board certification for veterinary reproduction specialists.  "There is no totally correct answer to the question about the optimum age for the procedure."  He says "owner concerns, breed predisposition, and specific situations related to each case and patient can all be weighed in making that judgment."

To make the best decisions for the pets they love, owners should ask their veterinarians to explain the evidence for benefits and risks regarding all treatment options.

Claudia Gray, DVM, a past president of the Niagara Frontier Veterinary Society, practices small animal medicine and surgery in Buffalo, New York.    Andrew Skolnick is a former associate news editor of the Journal of the American Medical Association. 


Male and Female:

  • Surgery and anesthesia times are shorter
  • Faster recovery from anesthesia and healing
  • Fewer surgical complications

Female Only:

  • Reduces the risk of mammary cancer, especially when spayed before second heat cycle


Male and Female:

  • 3-4 times higher risk of bone cancer if sterilized before maturity
  • Greater risk of hip dysplasia if sterilized before five months
  • Greater risk of ACL ruptures if sterilized before maturity
  • Risk of uneven bone growth that may lead to altered conformation and increased stress on bones and joints if sterilized before maturity

Female Only:

  • 2-5 time greater risk of blood vessel cancer of heart or spleen (hemangiosarcoma)
  • Greater risk of urinary tract infections caused by immature genitalia 
  • Greater risk of urinary incontinence, especially if spayed before 3 months

Male Only:

  • Nearly doubles the risk of blood vessel cancer (hemangiosarcoma)

Risks and Benefits come from the summaries of published research provided by the American College of Theriogenologists, the National Animal Interest Alliance, The Third International Symposium on Non-Surgical Contraceptive Methods for Control, the Journal of the American Veterinary Medical Association and the Association of Animal Behavior Professionals.


Larry S. Katz, PhD,Associate Professor and Chair 
Animal Sciences 
Rutgers University 
New Brunswick, NJ 08901

Dog owners in America are frequently advised to spay/neuter their dogs for health reasons. A number of health benefits are cited, yet evidence is usually not cited to support the alleged health benefits. 
When discussing the health impacts of spay/neuter, health risks are often not mentioned. At times, some risks are mentioned, but the most severe risks usually are not. This article is an attempt to summarize the long-term health risks and benefits associated with spay/neuter in dogs that can be found in the veterinary medical literature. This article will not discuss the impact of spay/neuter on population control, or the impact of spay/neuter on behavior. 

Nearly all of the health risks and benefits summarized in this article are findings from retrospective epidemiological research studies of dogs, which examine potential associations by looking backwards in time. A few are from prospective research studies, which examine potential associations by looking forward 
in time. 

An objective reading of the veterinary medical literature reveals a complex situation with respect to the long term health risks and benefits associated with spay/neuter in dogs. The evidence shows that spay/neuter correlates with both positive AND adverse health effects in dogs. It also suggests how much we really do not yet understand about this subject. 

On balance, it appears that no compelling case can be made for neutering most male dogs, especially immature male dogs, in order to prevent future health problems. The number of health problems associated with neutering may exceed the associated health benefits in most cases. 

On the positive side, neutering male dogs 
• eliminates the small risk (probably <1%) of dying from testicular cancer 
• reduces the risk of non-cancerous prostate disorders 
• reduces the risk of perianal fistulas 
• may possibly reduce the risk of diabetes (data inconclusive) 

On the negative side, neutering male dogs 
• if done before 1 year of age, significantly increases the risk of osteosarcoma (bone cancer); this is a common cancer in medium/large and larger breeds with a poor prognosis. 
• increases the risk of cardiac hemangiosarcoma by a factor of 1.6 
• triples the risk of hypothyroidism 
• increases the risk of progressive geriatric cognitive impairment 
• triples the risk of obesity, a common health problem in dogs with many associated health problems 
• quadruples the small risk (<0.6%) of prostate cancer 
• doubles the small risk (<1%) of urinary tract cancers 
• increases the risk of orthopedic disorders 
• increases the risk of adverse reactions to vaccinations 
For female dogs, the situation is more complex. The number of health benefits associated with spaying may exceed the associated health problems in some (not all) cases. On balance, whether spaying improves the odds of overall good health or degrades them probably depends on the age of the female dog and the relative risk of various diseases in the different breeds. 

On the positive side, spaying female dogs 
• if done before 2.5 years of age, greatly reduces the risk of mammary tumors, the most common malignant tumors in female dogs 
• nearly eliminates the risk of pyometra, which otherwise would affect about 23% of intact female dogs; pyometra kills about 1% of intact female dogs
• reduces the risk of perianal fistulas 
• removes the very small risk (≤0.5%) from uterine, cervical, and ovarian tumors 

On the negative side, spaying female dogs 
• if done before 1 year of age, significantly increases the risk of osteosarcoma (bone cancer); this is a common cancer in larger breeds with a poor prognosis 
• increases the risk of splenic hemangiosarcoma by a factor of 2.2 and cardiac hemangiosarcoma by a factor of >5; this is a common cancer and major cause of death in some breeds 
• triples the risk of hypothyroidism 
• increases the risk of obesity by a factor of 1.6-2, a common health problem in dogs with many associated health problems 
• causes urinary “spay incontinence” in 4-20% of female dogs 
• increases the risk of persistent or recurring urinary tract infections by a factor of 3-4 
• increases the risk of recessed vulva, vaginal dermatitis, and vaginitis, especially for female dogs spayed before puberty 
• doubles the small risk (<1%) of urinary tract tumors 
• increases the risk of orthopedic disorders 
• increases the risk of adverse reactions to vaccinations 
One thing is clear – much of the spay/neuter information that is available to the public is unbalanced and contains claims that are exaggerated or unsupported by evidence. Rather than helping to educate pet owners, much of it has contributed to common misunderstandings about the health risks and benefits associated of spay/neuter in dogs. 

The traditional spay/neuter age of six months as well as the modern practice of pediatric spay/neuter appear to predispose dogs to health risks that could otherwise be avoided by waiting until the dog is physically mature, or perhaps in the case of many male dogs, foregoing it altogether unless medically necessary. 

The balance of long-term health risks and benefits of spay/neuter will vary from one dog to the next. Breed, age, and gender are variables that must be taken into consideration in conjunction with non-medical factors for each individual dog. Across-the-board recommendations for all pet dogs do not appear to be supportable from findings in the veterinary medical literature. 

This section summarizes the diseases or conditions that have been studied with respect to spay/neuter in dogs. 

Complications from Spay/Neuter Surgery 
All surgery incurs some risk of complications, including adverse reactions to anesthesia, hemorrhage, inflammation, infection, etc. Complications include only immediate and near term impacts that are clearly linked to the surgery, not to longer term impacts that can only be assessed by research studies. 

At one veterinary teaching hospital where complications were tracked, the rates of intraoperative, postoperative and total complications were 6.3%, 14.1% and 20.6%, respectively as a result of spaying female dogs.

. Other studies found a rate of total complications from spaying of 17.7%2
 and 23%3
. A study of Canadian veterinary private practitioners found complication rates of 22% and 19% for spaying female dogs and neutering male dogs, respectively.
. Serious complications such as infections, abscesses, rupture of the surgical wound, and chewed out sutures were reported at a 1- 4% frequency, with spay and castration surgeries accounting for 90% and 10% of these complications, respectively.
The death rate due to complications from spay/neuter is low, at around 0.1%.
Read full study at:

And even More:

Read this for yourself at:  or read a below cut/paste of the study.

Health Implications in Early Spay and Neuter in Dogs

02/25/2013                                                                                                               Recent results from research funded by the AKC Canine Health Foundation have the potential to significantly impact recommendations for spaying and neutering dogs in the United States. Most dogs in the United States are spayed or neutered, and for years the procedures have been completed prior to maturity. The study, published in the prominent, open access journal PLOS One, suggests that veterinarians should be more cautious about the age at which they spay and neuter in order to protect the overall health of dogs.                                                                                                                                                                                                                                           A team of researchers led by Dr. Benjamin L. Hart at the University of California, Davis has completed  the most detailed study performed to date that evaluates incidence of cancer diagnoses and joint problems in one breed -- Golden Retrievers -- by neuter status: early (before 12 months old), late (12 months or older), and intact. Consistent with previous studies on the topic, the results showed increased likelihood of hemangiosarcoma, lymphoma, mast cell tumors, and canine cruciate ligament (CCL) rupture in neutered dogs.                                                                                                                                                                                                                         The most profound observations were in hip dysplasia in male dogs when comparing early and late-neutering. The risk of development of hip dysplasia doubles, and disease occurs at a younger age in the early-neuter group compared to both the intact and late-neuter group. No occurrence of CCL disease was observed in intact male or intact female dogs, or in late-neutered femalesIn early-neutered dogs, the incidence of CCL was 5.1 percent in males and 7.7 percent in females, suggesting that neutering prior to sexual maturity significantly increases a dog’s risk of developing CCL disease. With respect to cancer, cases of lymphoma were 3-fold greater in the early-neutered males. Interestingly, incidence of mast cell tumors (male and female dogs) and hemangiosarcoma (female dogs only) were highest in the late-neuter ground.                                                                                                                                               “Dr. Hart’s landmark study is the first to provide evidence for when to spay or neuter dogs. For years the veterinary community has been aware that early-spay and neuter may impact orthopedic health in dogs. Through a very detailed analysis and inclusion of body condition score as a risk factor, Dr. Hart was able to show that timing of spay and neuter does indeed have health implications,” said Dr. Shila Nordone, Chief Scientific Officer for the AKC Canine Health Foundation.                                                                                                                                                                                         “CCL disease is painful, debilitating, and costs dog owners $1 billion annually to treat. The AKC Canine Health Foundation is committed to funding research, like Dr. Hart’s study, that can lead to evidence-based health recommendations. Armed with prudent guidelines for when to spay and neuter dogs we will have a significant impact on the quality of life for dogs,” continued Dr. Nordone.                                                                                                                                                                                         Importantly, the task at hand is now to determine if the observations in this study are indeed true across all breeds and mixed breeds of dogs. Dr. Hart is interested in continuing his work by studying Labrador Retrievers, German Shepherd Dogs, and Dachshunds. Additionally, gaps in knowledge continue to exist concerning the complex relationship between sex hormones and cancer.                                                                                                                                                                                           Last summer the AKC Canine Health Foundation released a podcast interview with Dr. Hart on his early-spay and neuter research as part of a series dedicated to the health of the canine athlete. To listen to the podcast visit                                                                                                                                         The publication “Neutering Dogs: Effects on Joint Disorders and Cancers in Golden Retrievers” is available online through the open access journal PLOS One.  The work was funded by the AKC Canine Health Foundation with sponsorship from the Golden Retriever Foundation, Schooley's Mountain Kennel Club, the Siberian Husky Club of America, and the Vizsla Club of America Welfare Foundation.                                                                                                                                                                     See more at:

The topic of spay/neuter is emotionally charged for many pet owners.

It’s become the “responsible” thing to do and we commonly hear of the benefits of this surgery but rarely the risks.

And when savvy pet owners avoid early spay/neuter (or forego it altogether), to mitigate that risk, they’re frequently vilified for contributing to the pet over population problem. But decisions made on emotion aren’t usually the best kinds of decisions we can make.

So indulge me while I take an objective and scientific look at what’s causing all the fuss.

We’ll start with the most recent reason to reconsider spay/neuter.

In February 2014, a study was completed on over 2500 Vizsla dogs and the results were a blow to those who vehemently defend spay/neuter. But this latest study is just the most recent of a long line of work showing that removing a quarter of the dog’s endocrine system might not be in the dog’s best interest – and maybe not even in the best interests of rescues and shelters.

Let’s look at what this research shows as the three most important reasons you should reconsider spay/neuter.

1. Spay/Neuter and Joint Disease

We’ll get to the Vizsla study that I mentioned later. They didn’t investigate the link between spay/neuter and joint disease, but they didn’t really need to – there was already plenty of research showing the link.

Hip Dysplasia

A study on Golden Retrievers found that male dogs who were neutered before 12 months of age had double the risk of hip dysplasia than their intact counterparts (Torres de la Riva G, Hart BL, Farver TB, Oberbauer AM, Messam LLM, et al. (2013) Neutering Dogs: Effects on Joint Disorders and Cancers in Golden Retrievers)

Other research shows that dogs sterilized before the age of six months have a 70% increased risk of developing hip dysplasia. The authors of this study (Spain et al, JAVMA 2004), propose that …

“it is possible that the increase in bone length that results from early-age gonadectomy results in changes in joint conformation, which could lead to a diagnosis of hip dysplasia.”

There’s even more evidence that spay/neuter can increase the risk of hip dysplasia.

Van Hagen et al (Am J Vet Res, Feb 2005), found that of the sample dogs diagnosed with hip dysplasia, those that were neutered six months prior to the diagnosis were nearly twice as likely to develop hip dysplasia.

Interestingly, a study by Dannuccia et al (Calcif Tissue Int, 1986), found that removing the ovaries of Beagles caused increased remodeling of the pelvic bone, which also suggests an increased risk of hip dysplasia with spay.

Cruciate Ligament Tears

Cranial cruciate ligament tears have also been linked to spay/neuter in numerous studies.

The Golden Retriever study found that although there were no cases of cruciate tear in the intact dogs, 5% of males neutered before 12 months and 8% of females did suffer tears.

Whitehair et al (JAVMA Oct 1993), found that spayed and neutered dogs of any age were twice as likely to suffer cranial cruciate ligament rupture. Slauterbeck et al also found an increased risk (Clin Orthop Relat Res Dec 2004).

Chris Zinc DVM PhD DACVP explains,

“…if the femur has achieved its genetically determined normal length at eight months when a dog gets spayed or neutered, but the tibia, which normally stops growing at 12 to 14 months of age continues to grow, then an abnormal angle may develop at the stifle. In addition, with the extra growth, the lower leg below the stifle likely becomes heavier (because it is longer), and may cause increased stresses on the cranial cruciate ligament.”

Additionally, sterilization can cause a loss of bone mass (Martin et al, Bone 1987), and obesity (Edney et al, Vet Rec Apr 1986).

Both of these factors could lead to an increased risk of cranial cruciate ligament tear and hip dysplasia. Furthermore, spayed/neutered dogs are greater than three times more likely to suffer from patellar luxation (Vidoni et al, Wien Tierartztl Mschr 2005).

Check out how turmeric can be helpful for joint pain. Click here!

But there are even more sinister issues with spay/neuter.

2. Spay/Neuter and Cancer

Contrary to popular belief, we can’t spay/neuter cancer and, in fact, this surgery largely increases the risk of many common canine cancers.

MALES vs FEMALES: The Golden Retriever study looked at cancer rates and found that the incidence of lymphosarcoma was three times higher in males neutered before 12 months of age. Interestingly the percentage of hemangiosarcoma in females spayed after 12 months was four times higher than that of intact and even early-spayed females. Additionally, 6% of females spayed after 12 months were affected with mast cell cancer, while there were zero cases among the intact females.

These results are similar to other studies.

The more recent Vizsla study found that spayed females had significantly higher rates of hemangiosarcoma (nine times higher) than intact females.

They also found that spayed/neutered dogs were 3.5% more likely to suffer mast cell cancer and 4.3 times more likely to suffer lymphoma. (M. Christine Zink, DVM, PhD et al., Evaluation of the risk and age of onset of cancer and behavioral disorders in gonadectomized Vizslas. JAVMA, Vol 244, No. 3, February 1, 2014)

SPAYED vs INTACT: In fact, the incidence of all cancers in spayed females was 6.5 times higher and in neutered males was 3.6 times higher than intact dogs.

YOUNG DOGS: They also found that the younger the dogs were spayed/neutered, the younger they were when diagnosed with cancer.

Waters et al. (Exploring mechanisms of sex differences in longevity: lifetime ovary exposure and exceptional longevity in dogs) found similar results in their study of female Rottweilers. The researchers set out to determine whether retaining the ovaries contributed to longevity. In Rottweilers, the major causes of death are sarcoma and other cancers, which account for 38% and 73% of deaths respectively.

After excluding all cancer deaths, females who kept their ovaries during the first seven years of life were more than nine times more likely to reach exceptional longevity than females with the shortest ovary exposure. Although intact female dogs were more likely than males to achieve exceptional longevity, that advantage was erased with spay.

3. Spay/Neuter and Behavior

Although spay/neuter had been previously linked to cognitive impairment and even a three fold risk of hypothyroidism, which often creates behavior changes, the Viszla study yielded some particularly interesting insight into this link.

In the study, spayed and neutered dogs were also more likely to develop behavior disorders than intact dogs.

This included:

  • fear of storms
  • separation anxiety
  • fear of noises
  • timidity
  • excitability
  • aggression
  • hyperactivity
  • fear biting.

Another study found neutered dogs were more:

  • aggressive
  • fearful
  • excitable
  • less trainable than intact dogs

(Parvene Farhoody @ M. Christine Zink, Behavioral and Physical Effects of  Spaying and Neutering Domestic Dogs, May 2010)

This is contrary to the popular belief that neutering reduces aggression and other behavior problems.

There’s Nothing Routine About Spay/Neuter

These findings also present a conundrum for shelters and rescues who advocate spay/neuter.

Although reducing the number of dogs in shelters is an important goal, it’s more important to prevent them from ending up at the shelter. While most people believe that shelters are full because of over population, behavior problems are the most common reason owners give up their dogs.

Moreover, is it fair for shelters to burden adoptive families with the increased risk of cancer and joint disease?

There are alternatives to the complete removal of the reproductive organs and this might play a role in reducing the risk of cancer, joint disease and behavior issues.

Spay is “instant menopause” and immediately shuts off the supply of protective hormones that are obviously involved in much more than just reproduction. Modified spay/neuter surgeries have less impact on the hormones and endocrine system, so dogs will enjoy more protection, even when sterilized.

Hormones produced by the reproductive organs not only are essential for reproduction, but in the development of:

  • homeostasis
  • body condition
  • cholesterol levels
  • energy levels
  • urinary continence
  • muscle tone
  • cognition
  • behavior
  • and, most importantly, they also play a role in the immune system

The rise in the risk of many cancers in response to the removal of the reproductive organs is evidence of this.


In females, a partial spay, or ovary-sparing spay or tubal ligation are safer options.

In males, vasectomy can also be a safer option. There is also a zinc injection that has recently come into favor. Hopefully this research will encourage more shelters to look into these safer and less intrusive options.

Finally, if your goal is to give your dog the best chance at a life free of joint disease, cancer and behavior issues, then keeping your dog intact is certainly an option.

If you’re thoughtful and caring enough to get this far in the article, you’re certainly thoughtful enough to manage an intact dog. Simply make certain your intact male isn’t allowed to wander and keep your intact female on leash for a few weeks when she is in estrus.

Removing a significant part of your dog’s endocrine system should be anything but routine. As research continues to show the damning results of spay/neuter, it’s certainly in your dog’s best interests for you to consider these three important reasons to keep your best friend just the way mother nature made him.

By Dr. Becker

There is a growing body of evidence — including new research on German Shepherd Dogs (which I’ll discuss shortly) — that indicates spaying or neutering, in particular as it relates to large breed dogs desexed early in life, significantly increases the risk of serious health problems.

For Female Rottweilers, Ovary Removal Significantly Increases the Risk for a Major Fatal Disease

In 2009, a Gerald P. Murphy Cancer Foundation study found a correlation between the age at which female Rottweilers are spayed and their lifespan.1 The study compared female Rotties who lived to be 13 or older with a group who lived the expected lifespan of about 9 years.

According to lead researcher Dr. David J. Waters, a professor in the Department of Veterinary Clinical Sciences (VCS) at Purdue University:

"Like women, female dogs in our study had a distinct survival advantage over males. But taking away ovaries during the first [four] years of life completely erased the female survival advantage.

“We found that female Rottweilers that kept their ovaries for at least [six] years were [four] times more likely to reach exceptional longevity compared to females who had the shortest lifetime ovary exposure."2

Because death from cancer is so prevalent in Rotties, researchers conducted a subgroup analysis of only dogs that did not die of cancer. This focused research further proved the strong association between intact ovaries and longevity.

Even in dogs that did not die of cancer, the females who kept their ovaries the longest were nine times more likely to achieve exceptional longevity (13+ years). Simply put, study results indicate removal of a Rottweiler’s ovaries significantly increases the risk for a major lethal disease.

Did You Know That in Europe, Intact Dogs Are the Norm?

A more recent study conducted at the University of California (UC), Davis provides additional evidence that spaying or neutering, and the age at which it is done, may increase a dog's risk of certain cancers and joint diseases.

The U.S. takes a very different approach to spay/neuter compared to many European countries. In this country, not only are most dogs spayed or neutered, increasingly the preferred timing of the procedure is before the animal is a year old.

The motivation is for desexing is pet population control, and owners are considered responsible only if their pet has been sterilized. However, in many European countries, dogs remain intact and animal health experts do not promote spaying or neutering. The UC Davis study was undertaken, according to the researchers because:

"Given the importance of gonadal hormones in growth and development, this cultural contrast invites an analysis of the multiple organ systems that may be adversely affected by neutering."3

In Desexed US Golden Retrievers, the Rates of Joint Disease and Cancer Are Much Higher Than in Intact Goldens

The researchers looked at the health records of 759 Golden Retrievers. Goldens were chosen because they are one of the most popular breeds in the U.S. and Europe, are often used as service dogs, and are also susceptible to various cancers and joint disorders.

The intent of the study was to investigate the effects of neutering on the risks of several diseases in a single breed of dog, distinguishing between males and females, and between dogs that had been neutered or spayed early (before one year), late (after one year), or not at all.

The dogs ranged in age from 1 to 8 years and had been seen at the UC Davis William R. Pritchard Veterinary Medical Teaching Hospital for one or more of the following problems:

The researchers focused on joint disorders and cancers because desexing removes the testes or ovaries and disrupts production of hormones that play an important role in body processes like bone growth plate closure.

Study results indicated that for all five diseases, the rates were significantly higher in both males and females that were neutered or spayed (before or after one year of age) compared with intact dogs.

Of special concern was that results showed a 100 percent increase in the rate of hip dysplasia in male Goldens neutered before 12 months of age.

Ten percent were diagnosed with the condition, which was double the rate of occurrence in intact males. Past studies have reported a 17 percent increase among all neutered dogs compared to all intact dogs.

The UC Davis researchers suggest that neutering male Golden Retrievers well beyond puberty will help prevent an increased risk of hip dysplasia, cranial cruciate ligament injury, and lymphosarcoma. For female Goldens, the research team concluded that:

“ … [T]he timing of neutering is more problematical because early neutering significantly increases the incidence rate of CCL from near [zero] to almost 8 percent, and late neutering increases the rates of HSA to 4 times that of the 1.6 percent rate for intact females and to 5.7 percent for, which was not diagnosed in intact females.” 4

Vizsla Study Suggests a Significantly Increased Risk for Cancer and Behavioral Disorders in Spayed or Neutered Dogs

A 2014 study of Vizslas included over 2,500 dogs and revealed that dogs neutered or spayed at any age were at significantly increased risk for developing mast cell cancer, lymphoma, all other cancers, all cancers combined, and fear of storms, compared with intact Vizslas.5

Dogs of both genders neutered or spayed at 6 months or younger had significantly increased odds of developing a behavioral disorder, including separation anxiety, noise phobia, timidity, excitability, submissive urination, aggression, hyperactivity, and/or fear biting.

When it came to thunderstorm phobia, all neutered or spayed Vizslas were at greater risk than intact Vizslas, regardless of age at neutering. The younger the age at neutering, the earlier the age at diagnosis with mast cell cancer, cancers other than mast cell, hemangiosarcoma, lymphoma, all cancers combined, a behavioral disorder, or fear of storms.

Spayed female Vizslas had a nine times higher incidence of hemangiosarcoma compared to intact females, regardless of when spaying was performed, however, no difference in incidence of this type of cancer was found for neutered vs. intact males. Neutered and spayed dogs had 4.3 times higher incidence of lymphoma, regardless of age at time of neutering, and a five times higher incidence of other types of cancer.

Spayed females had 6.5 times higher incidence of all cancers combined compared to intact females, and neutered males had 3.6 times higher incidence than intact males. The Vizsla researchers concluded:

"Additional studies are needed on the biological effects of removing gonadal hormones and on methods to render dogs infertile that do not involve gonadectomy.”6

German Shepherds Desexed Before 1 Year of Age Triple Their Risk of Joint Disorders

As I mentioned earlier, another very recent study was conducted at UC Davis, this time involving German Shepherds Dogs (GSDs). The study results suggest that spaying or neutering before 1 year of age triples the risk of joint disorders, in particular cranial cruciate ligament tears, in these dogs.7

The researchers analyzed the veterinary records of 1,170 GSDs, both neutered or spayed and intact, for a 14.5-year period. They looked for joint disorders and cancers already linked to desexing, and separated the dogs into categories that included intact, desexed before 6 months, between 6 and 11 months, and between 12 and 23 months.

The study found that 7 percent of intact males were diagnosed with one or more joint disorders compared with 21 percent of males neutered prior to 1 year of age. Five percent of intact females developed joint disorders, compared with 16 percent of females spayed before 1 year.

Intact female GSDs were found to develop mammary cancer at a rate of 4 percent, compared with less than 1 percent of females spayed before 1 year. Intact females had no diagnosed incidence of urinary incontinence, compared with 7 percent of females spayed before 1 year. According to lead researcher Dr. Benjamin Hart of the UC Davis School of Veterinary Medicine:

"Debilitating joint disorders of hip dysplasia, CCL and elbow dysplasia can shorten a dog's useful working life and impact its role as a family member. Simply delaying the spay/neuter until the dog is a year old can markedly reduce the chance of a joint disorder."8

My Preference Is to Sterilize, Not Desex

Since simply delaying a spay or neuter until a dog is older doesn’t address all the health challenges we see in desexed versus intact pets, I like the Vizsla researchers' conclusion above that we need to investigate alternative methods of sterilizing dogs that do not involve removing the ovaries or testes.

As I explain in this video, over the years I've changed my view on spaying and neutering dogs, based not just on research studies, but also on the health challenges faced by so many of my canine patients after I spayed or neutered them. These were primarily irreversible metabolic diseases that appeared within a few years of a dog's surgery.

These days I work with each individual pet owner to make decisions that will provide the most health benefits for the dog. Whenever possible, I prefer to leave dogs intact. However, this approach requires a highly responsible pet guardian who is fully committed to and capable of preventing the dog from mating (unless the owner is a responsible breeder and that's the goal).

My clients are incredibly responsible and educated. I’ve never had a single unplanned pregnancy in my veterinary career. But I realize I’m not providing medical care to the entire world, and the world is full of irresponsible people.

My second choice is to sterilize without desexing. This means performing a procedure that will prevent pregnancy while sparing the testes or ovaries so they continue to produce hormones essential for the dog's health. This can be done at any age, and could easily replace the current standard of desexing by high volume spay/neuter clinics and shelters around the country.

This typically involves a vasectomy for male dogs, and a modified spay for females. The modified spay removes the uterus while preserving the hormone-producing ovaries. This procedure is less invasive, requires shorter time under anesthesia, and yields the same results with no negative side effects.