Nav: Home

Spay and neuter for dogs: Avoiding the health consequences

October 30, 2018

In 1973, the pet overpopulation problem in the United States reached a critical point with 13 million animals ending up in shelters, according to the Humane Society of the United States. Animal rescue and welfare communities supported wide-scale spay and neuter programs to combat the problem. This effort, among others, has resulted in half as many pets in shelters today.

Spaying or neutering are now viewed as an obligation of responsible pet ownership in this country. The procedures are taught in veterinary school and have become staples of veterinary practice. Removal of the ovaries and uterus in females (spaying, or ovariohysterectomy in medical terms) and removal of the testes in males (neutering, or orchiectomy in medical terms) sterilizes the pet and eliminates all the reproductive hormones.

Gonadectomy and health, a controversial topic

It's no surprise that removing sex hormones can affect an animal's behavior, health and long-term welfare. However, research in dogs has only recently illuminated the nature and extent of the impacts of removing the gonads (or gonadectomy), including an array of positive and negative outcomes. For example, removal of the ovaries and testes eliminates the risk of cancer in those organs and lowers the risk of related conditions such as breast cancer and prostate enlargement; but it has also been related to an increased incidence of a variety of non-reproductive cancers, joint and ligament ailments, incontinence, obesity and behavior problems. Outcomes depend on many factors, such as the dog's breed, sex, and age at spay/neuter.

Discussion among professionals on gonadectomy and health has become heated. Some veterinarians view the health implications of gonadectomy as so concerning that its widespread practice needs to be reconsidered. Others, especially those affiliated with animal rescue and welfare groups, steadfastly support routine spay and neuter programs to combat overpopulation. In the middle are the dog owners who just want whatever is best for their pets.

New data and solutions

The authors of this month's review article in Innovative Veterinary Care Journal bring a fresh perspective. Dr. Michelle Kutzler, a veterinarian at Oregon State University and expert in animal reproduction and contraception, has studied the mechanisms of diseases resulting from hormone loss. In an intact dog, the interplay of hormones is precisely regulated through feedback loops. When the gonads are removed, the feedback is lost for reproductive hormones produced in the brain, causing luteinizing hormone (LH) to be produced at a high, unhealthy concentration throughout the dog's life. How does this influence disease processes that have nothing to do with the reproductive system? Dr. Kutzler and colleagues have found LH receptors in other body systems, predisposing dogs to developing health problems in those tissues.

Dr. Kutzler is an outspoken advocate for the adoption of alternatives to traditional spay and neuter that preserve hormones and noted, "The LH concentration in gonadectomized dogs can be thirty times higher than in normal adult dogs. Lifelong overstimulation by LH is likely related to the number and diversity of health problems we see in dogs that have undergone traditional spay and neuter."

The burning question is: can we preserve hormones while ensuring that a dog will not reproduce? The affirmative answer is simple (and familiar to most people who deal with human contraception and family planning issues). The authors provide a review of the options available in the article.

Here is a snapshot of hormone-sparing alternatives to gonadectomy:
  • Male contraception: Vasectomy is the procedure of choice, as it is a relatively simple procedure. A dog can be castrated if testicular disease develops later in life, and he will have benefitted from many years of natural hormones.

  • Female contraception: Hysterectomy, also called ovary-sparing spay, is the best option. This procedure simply removes the entire uterus but not the ovaries.

  • Separation: This option may not be for everyone, since it requires the owner to keep intact male dogs away from intact female dogs while they are in heat. If this sounds difficult, keep in mind that in most Scandinavian countries there is no dog overpopulation problem and gonadectomy is uncommon.

  • On the horizon: A number of nonsurgical options are also under development, including injectable sterilants, male sterilization by applying ultrasound waves, and epididymal ligation for males.

The authors encourage discussion between the pet owner and veterinarian on the pros and cons of each option. An individualized approach is recommended, since each dog and each circumstance is different.

Because many people have never had dogs with natural hormones, it is also important to consider that those dogs will display sexual and other hormonally-influenced behaviors. But large-scale studies are finding that the relationship between hormones and behavior is not linear, and a variety of other factors can influence behavior. The Innovative Veterinary Care Journal article discusses these issues.

Where do we go from here

Unfortunately, very few veterinarians offer alternative contraceptive methods. Even if a dog owner has researched this topic and believes that a hormone-preserving method such as vasectomy or ovary-sparing spay is the best option, he or she may be hard pressed to find a local veterinarian who offers it. As a service to the public, in 2015 Parsemus Foundation started a referral list of veterinarians and clinics in North America that offer alternatives to traditional spay and neuter that now includes over 100 clinics in the U.S and Canada. However, Parsemus Foundation has found that demand among dog owners for these services far exceeds supply.

A survey by Dr. Kutzler conducted at the 2017 and 2018 American Veterinary Medical Association meetings found that while 73% of practitioners discussed long-term health risks of spay and neuter with clients, only 7% offered alternative procedures. This may be because the veterinarians are not aware of the latest research indicating that the balance of data now favors preserving hormones, or they are simply not familiar with these alternative procedures. Furthermore, if an individual wishes to adopt a rescue dog from a shelter, it is often mandatory that the dog be spayed or neutered prior to release.

"Like most pet owners, I never thought much about having my dogs spayed or neutered. It was the responsible thing to do," says Dr. Linda Brent, the Executive Director of Parsemus Foundation. "So I didn't think twice when I adopted a dog, and the shelter required neuter surgery prior to release. But this outgoing, fit puppy developed obesity and severe anxiety shortly after the procedure, which will impact his welfare for the rest of his life. My personal experience is not uncommon, and I am proud that Parsemus Foundation has taken a leading role in advocating for increased research, dialogue and education about alternatives to traditional spay and neuter. With these alternatives, we can reduce pet overpopulation while preserving individual pets' health, too."

Parsemus Foundation provides information for the public and veterinarians about alternatives to traditional spay and neuter, including instruction on the ovary-sparing spay procedure and a free referral listing service for veterinarians who offer alternative contraceptive options for pets.
-end-
Article link: The article is available online from Innovative Veterinary Care Journal at: http://www.ivcjournal.com/spay-neuter-alternatives

About Parsemus Foundation: Parsemus Foundation works to advance innovative and neglected medical research. The foundation supports studies and then seeks to raise awareness of the results, to ensure that they change treatment practice rather than disappear into the scientific literature. Many of the studies the foundation supports involve low-cost approaches that are not under patent, and are thus unlikely to be pursued by pharmaceutical companies due to limited profit potential. Successful studies to date have included breast cancer treatment advances, nonsurgical dog and cat sterilization, and non-invasive treatment of benign prostatic hyperplasia. More information on Parsemus Foundation and the work presented here can be found at: http://www.parsemus.org

Parsemus Foundation

Related Behavior Articles:

How synaptic changes translate to behavior changes
Learning changes behavior by altering many connections between brain cells in a variety of ways all at the same time, according to a study of sea slugs recently published in JNeurosci.
I won't have what he's having: The brain and socially motivated behavior
Monkeys devalue rewards when they anticipate that another monkey will get them instead.
Unlocking animal behavior through motion
Using physics to study different types of animal motion, such as burrowing worms or flying flocks, can reveal how animals behave in different settings.
AI to help monitor behavior
Algorithms based on artificial intelligence do better at supporting educational and clinical decision-making, according to a new study.
Increasing opportunities for sustainable behavior
To mitigate climate change and safeguard ecosystems, we need to make drastic changes in our consumption and transport behaviors.
Predicting a protein's behavior from its appearance
Researchers at EPFL have developed a new way to predict a protein's interactions with other proteins and biomolecules, and its biochemical activity, merely by observing its surface.
Spirituality affects the behavior of mortgagers
According to Olga Miroshnichenko, a Sc.D in Economics, and a Professor at the Department of Economics and Finance, Tyumen State University, morals affect the thinking of mortgage payers and help them avoid past due payments.
Asking if behavior can be changed on climate crisis
One of the more complex problems facing social psychologists today is whether any intervention can move people to change their behavior about climate change and protecting the environment for the sake of future generations.
Is Instagram behavior motivated by a desire to belong?
Does a desire to belong and perceived social support drive a person's frequency of Instagram use?
A 3D view of climatic behavior at the third pole
Research across several areas of the 'Third Pole' -- the high-mountain region centered on the Tibetan Plateau -- shows a seasonal cycle in how near-surface temperature changes with elevation.
More Behavior News and Behavior Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Making Amends
What makes a true apology? What does it mean to make amends for past mistakes? This hour, TED speakers explore how repairing the wrongs of the past is the first step toward healing for the future. Guests include historian and preservationist Brent Leggs, law professor Martha Minow, librarian Dawn Wacek, and playwright V (formerly Eve Ensler).
Now Playing: Science for the People

#566 Is Your Gut Leaking?
This week we're busting the human gut wide open with Dr. Alessio Fasano from the Center for Celiac Research and Treatment at Massachusetts General Hospital. Join host Anika Hazra for our discussion separating fact from fiction on the controversial topic of leaky gut syndrome. We cover everything from what causes a leaky gut to interpreting the results of a gut microbiome test! Related links: Center for Celiac Research and Treatment website and their YouTube channel
Now Playing: Radiolab

The Flag and the Fury
How do you actually make change in the world? For 126 years, Mississippi has had the Confederate battle flag on their state flag, and they were the last state in the nation where that emblem remained "officially" flying.  A few days ago, that flag came down. A few days before that, it coming down would have seemed impossible. We dive into the story behind this de-flagging: a journey involving a clash of histories, designs, families, and even cheerleading. This show is a collaboration with OSM Audio. Kiese Laymon's memoir Heavy is here. And the Hospitality Flag webpage is here.