Routine spaying and neutering of dogs is generally accepted, and some doggy daycares and dog parks don鈥檛 allow intact male dogs or female dogs in heat. In addition, many states require dogs in rescue shelters to be spayed or neutered before they鈥檙e placed in a home, often at just a few months old. Along with reducing pet overpopulation, spaying or neutering helps prevent unwanted litters that result in millions of dogs and cats being euthanized each year in the United States.
Nevertheless, a growing body of research suggests that spaying and neutering dogs, especially young dogs of large or giant breeds, can increase their chances of developing serious health conditions. Before going ahead with this procedure, make sure to consult with your veterinarian about the appropriate timing and the potential risks and benefits of spay-neuter.
What is Spay-Neuter?
Spay-neuter refers to the veterinary surgical practice of removing a dog鈥檚 reproductive organs, called the gonads. An exception to this practice is breeders who elect to keep their dogs intact for breeding purposes. Three common sterilization procedures are:
- Ovariohysterectomy (the typical spay) is the removal of the ovaries, fallopian tubes, and uterus, resulting in the dog being unable to reproduce
- Ovariectomy involves removing the ovaries while leaving the uterus intact
- Orchiectomy (the typical neuter) is the removal of the testicles, which makes the dog unable to reproduce, eliminates the main source of reproductive hormones, and may reduce or eliminate male breeding behaviors
What Are the Benefits and Risks of Spay-Neuter?
鈥淲hen it comes to dogs, there is no one-size-fits-all recommendation,鈥� says Dr. Jerry Klein, DVM, Chief Veterinary Officer for the American Kennel Club. The veterinarian will consider your dog鈥檚 age, breed, size, health status, sex, role (if they鈥檙e a pet or working dog), personality, and home environment in determining the optimal timing for this procedure. Generally, it seems better to delay surgery until the dog is more mature, he says.
For large and giant dog breeds, this could mean waiting until the dog is 12 months or older. In many cases, the benefits of spay-neuter outweigh the risks, he says. Still, it鈥檚 important to speak with your veterinarian about the benefits and risks of this procedure.
Benefits
- Reducing pet overpopulation and promoting a longer lifespan for dogs and cats
- Eliminating female dogs鈥� heat cycles and reducing mating-related behaviors, which can be frustrating to owners
- Reducing male dogs鈥� breeding instinct, resulting in less roaming and urine-marking behavior
- Preventing future possible such as pyometra (a serious and potentially life-threatening infection of the uterus)
- Protecting male dogs by eliminating the risk of testicular cancer and reducing the risk of developing enlarged prostate glands (known as benign prostatic hyperplasia)
- Preventing and reducing the risk of breast cancer in female dogs
Risks
- Complications due to the surgery itself or being anesthetized
- Endocrine issues, especially in dogs with underlying health problems
- Greater chance of some types of cancers
- Increased risk of orthopedic disorders and soft tissue injuries
- Susceptible to urinary issues due to the presence or absence of hormones
Besides spay-neuter, other surgical options can prevent dogs from reproducing while keeping their hormone-producing gonads intact, Dr. Klein explains. These surgical sterilization methods, although used less frequently, aren鈥檛 expected to affect behaviors associated with the breeding instinct, he adds.
What Does Research Say About Health Outcomes?
A few decades ago, it became standard practice in veterinary medicine to neuter dogs at six months of age or even younger, in some cases. Since then, this practice has come under scrutiny with emerging research on the resulting health outcomes, Dr. Klein says. These include a (e.g., hip dysplasia), urinary incontinence, and some forms of cancer, according to a 2021 article.
One of the report鈥檚 lead authors, Dr. Benjamin Hart of the University of California, Davis, has been researching the effects of spay-neuter with support from the for a decade. His team found that early spaying and neutering is associated with an increased risk of joint disorders among large breed dogs, such as Golden Retrievers, Labrador Retrievers, and German Shepherd Dogs. More recently, these researchers conducted a retrospective study, investigating tens of thousands of dogs from 35 breeds, focusing on early spay-neuter before the dog reached sexual maturity. They found that the health consequences of the procedure varied widely between breeds.
鈥淚t鈥檚 hard to predict which ones will and won鈥檛 have an increase in cancers or joint disorders with early spay-neuter,鈥� Dr. Hart says. For instance, in almost all dogs weighing less than 20 kilograms (about 45 pounds), there was no increased incidence of joint problems and cancers compared to intact dogs. One exception is the Shih Tzu. Early neutering of male Shih Tzu was associated with higher rates of some cancers.
The team found that, for dogs weighing more than 20 kilograms, the impact of early spay-neuter varies considerably across breeds and sexes. While small dogs didn鈥檛 experience higher rates of cancers and joint problems, Dr. Hart predicted that dogs at the other end of the scale, like Great Danes, might suffer these effects at a higher rate. An unexpected result was that these gentle giants had no increase in joint disorders after early spay-neuter.
Moreover, negative outcomes from spay-neuter were often limited to dogs neutered before they had . However, this isn鈥檛 always the case. For instance, female Golden Retrievers spayed after 12 months of age were four times as likely to develop hemangiosarcoma (an invasive cancer that causes damage to blood vessels) as intact females and even early spayed ones. Accordingly, more research is needed to understand breed-specific risks and benefits of spay-neuter.
How Have Views Evolved on the Timing of Spay-Neuter?
For a long time, many people believed that spaying or neutering a dog could , as well as prostate and mammary cancers. Dr. Hart鈥檚 research revealed that neutering male dogs with aggression problems only resolved aggression in 25 to 30 percent of cases. In other words, three out of four dogs didn鈥檛 show an improvement in aggressive behavior after neutering alone. Significantly, those behavioral improvements were equally likely if a dog was neutered once they reached sexual maturity.
Based on available data, neutering doesn鈥檛 . 鈥淎s a matter of fact, prostate cancer in males is more common in neutered than intact dogs,鈥� Dr. Hart says.
Existing studies on the incidence of mammary cancer are less conclusive, but through the 蜜桃视频 Canine Health Foundation and other institutions, so further guidance on decision-making is on its way. Meanwhile, Dr. Hart points out that both prostate and mammary cancer are relatively uncommon in dogs, whether they鈥檙e intact or neutered/spayed. Although testicular cancer is more common in older intact male dogs, it has better treatment outcomes compared to other cancers.
What Do Experts Advise Today?
鈥淭he take-home message is that it depends on a lot of different factors,鈥� says Dr. Sharon Albright, Manager of Communications and Veterinary Outreach at the . These include the breed, sex, any major health concerns, and what the owner intends to do with the dog. She recommends speaking to your veterinarian to reach a decision that takes into account recent research, as well as the dog鈥檚 expected lifestyle. For instance, owners of active dogs (e.g., jogging partners or dog sports champions) should be well aware of the risk of joint problems before making a decision on spay-neuter.
Dr. Hart agrees. 鈥淥ne of the things I emphasize is the need for a paradigm change with regard to veterinarian-client relationships,鈥� he says. He and his team would like the question of whether and when to spay or neuter to be a true discussion point between the veterinarian and the client. Both parties need to have all the necessary information about the likely impacts on the dog in question.
Dr. Albright also stresses that it鈥檚 important to consider how serious, common, and treatable the possible health outcomes are on each side of the spay-neuter decision, while also weighing the health and well-being impacts of unwanted pregnancies.
Keep in mind Dr. Hart鈥檚 advice that, although the risk of developing certain cancers and joint disorders increases when certain breeds are spayed or neutered early, most dogs won鈥檛 develop these conditions. The emerging research gives us a picture of the likelihood of certain outcomes, but it can never fully predict what life will look like for your dog.
Like people, each dog is an individual with their own of health and lifestyle needs, Dr. Klein says. For decades, America鈥檚 dogs were treated with a blanket rule about their reproductive organs. Though more research on spay-neuter is needed, with the information already available, dog owners can start working with veterinarians to make better, more informed decisions about what鈥檚 best for these beloved family members.
The Takeaways
While they鈥檙e major surgical procedures, veterinarians commonly perform spay-neuter procedures as they pose a low risk to a dog鈥檚 health and are thought to contribute to the improvement of over population of pets. Early spay-neuter can increase the risk of joint disorders and certain cancers, but the likelihood of these outcomes depends on the dog鈥檚 breed and age, as well as other factors. You should reach a decision about whether to spay-neuter and the appropriate timing through an informed discussion with a veterinarian about the risks and benefits of the procedure.
This article is intended solely as general guidance, and does not constitute health or other professional advice. Individual situations and applicable laws vary by jurisdiction, and you are encouraged to obtain appropriate advice from qualified professionals in the applicable jurisdictions. We make no representations or warranties concerning any course of action taken by any person following or otherwise using the information offered or provided in this article, including any such information associated with and provided in connection with third-party products, and we will not be liable for any direct, indirect, consequential, special, exemplary or other damages that may result, including but not limited to economic loss, injury, illness or death.