Research on the Effects of Spaying and Neutering
There is a growing body of research showing that spaying and neutering dogs is not the innocuous surgery once thought.
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Good Dog is on a mission to educate the public and make it simple for people to get dogs from good sources and for reputable breeders, shelters and rescues to put their dogs in good homes.
Good Dog is on a mission to educate the public and make it simple for people to get dogs from good sources and for reputable breeders, shelters and rescues to put their dogs in good homes.
There is a growing body of research showing that spaying and neutering dogs is not the innocuous surgery once thought. To help you determine if and when you should spay or neuter your dog, here is the current research on the long-term effects of these surgeries, as well as
Good Dog is on a mission to educate the public and make it simple for people to get dogs from good sources and for reputable breeders, shelters and rescues to put their dogs in good homes.
One important note: there are now several recent (2020) publications that show that mammary cancer rates, though higher in intact bitches, fall far, far short of the 25% threatened by many vets. Ben and Lynnette Hart’s 2020 paper show it to be highly variable but usually less than 6%. For example, intact Australian Cattle Dogs had no cases of mammary cancer while 8% of bitches spayed between 2 and 8 years had mammary cancer. In beagles and Bernese Mountain Dogs, no spayed or intact bitches had mammary cancer.
In comparison, rates of other cancers, such as hemangiosarcoma and mast cell tumors, were increased in some breeds like golden retrievers up to 17%, in Irish Wolfhounds to 25%! Owners must consider that spaying (and neutering) may increase the risk of untreatable cancers like hemangio even if it lowers the rate of the more treatable mammary cancer. Spaying and neutering also have a highly variable effect on the development of joint disease, pyometria, and urinary incontinence depending upon breed.
Our recommendation is that owners take time to understand how these dramatic surgeries affect their breed and how they may affect their dog’s adult temperament before making the decision to spay or neuter.
Research Addressing Age-and Breed-Specific Spay/Neuter Recommendations
- Assisting Decision-Making on Age of Neutering for 35 Breeds of Dogs: Associated Joint Disorders, Cancers, and Urinary Incontinence, Hart, Benjamin & Hart, Lynette & Thigpen, Abigail & Willits, Neil (2020).
- Best age for spay and neuter: a new paradigm. Hart, Benjamin & Hart, Lynette & Thigpen, Abigail & Willits, Neil (2019).
Watch Good Dog's Webinar on Spay/Neuter with Leading Vet Experts
Listen to world-renowned leading canine behaviorist and co-creator of C-BARQ, Dr. James Serpell, and veterinary specialist, Vet of the Year, Dr. Chris Zink, DVM, discuss recent research on the effects of early spay/neuter on our dogs’ health, behavior and more. Watch the webinar here.
Cancer and Other Long-Term Diseases
- Associations between neutering and idiopathic epilepsy in Labrador retrievers and Border collies under primary veterinary care in the UK, S.Van Meervenne, HA Volk, et al (2019)
- Non-Reproductive Long-Term Health Complications of Gonad Removal in Dogs as Well as Possible Causal Relationships with Post-Gonadectomy Elevated Luteinizing Hormone (LH) Concentrations K Zwida and MA Kutzler (2016)
- Canine hemangiosarcoma expresses luteinizing hormone (LH) receptors K Zwida and MA Kutzler (2016)
- Gonadectomy effects on the risk of immune disorders in the dog: a retrospective study C R Sundburg, J Belanger, et al. (2016)
- Neutering of German Shepherd Dogs: associated joint disorders, cancers and urinary incontinence B Hart, L Hart, et al. (2016)
- Long-Term Health Effects of Neutering Dogs: Comparison of Labrador Retrievers with Golden Retrievers B Hart, L Hart, et al. (2014)
- Neutering Dogs: Effects on Joint Disorders and Cancers in Golden Retrievers G Torres de la Riva, B Hart, et al. (2013)
- Behavioral and Physical Effects of Spaying and Neutering Domestic Dogs (Canis familiaris) P Farhoody (2010)
- Exploring the mechanisms of sex differences in longevity: lifetime ovary exposure and exceptional longevity in dogs DJ Waters, SS Kengeri, et al (2009)
- Long-Term Health Risks and Benefits Associated with Spay / Neuter in Dogs L Sanborn (2007)
- Determining the optimal age for gonadectomy of dogs and cats MV Kustritz (2007)
- Early Spay-Neuter Considerations for the Canine Athlete: One Veterinarian’s Opinion MC Zink (2005)
- A Healthier Respect for Ovaries D Waters
Pyometra
- Life course analysis of the impact of mammary cancer and pyometra on age-anchored life expectancy in female Rottweilers: Implications for envisioning ovary conservation as a strategy to promote healthy longevity in pet dogs Waters DJ, SS Kengeri, et al. (2017)
- Breed Risk of Pyometra in Insured Dogs in Sweden A Egenvall, R Hagman, et al. (2001)
Breast (Mammary) Cancer in Dogs
- Life course analysis of the impact of mammary cancer and pyometra on age-anchored life expectancy in female Rottweilers: Implications for envisioning ovary conservation as a strategy to promote healthy longevity in pet dogs Waters DJ, SS Kengeri, et al. (2017)
- Population-based incidence of mammary tumours in some dog breeds Moe, L (2001)
- Incidence of and survival after mammary tumors in a population of over 80,000 insured female dogs in Sweden from 1995 to 2002 A Egenvall (2005)
- Factors Influencing Canine Mammary Cancer Development and Postsurgical Survival R Schneider, CR Dom, DON Taylor (1969)
Obesity
- Age at gonadectomy and risk of overweight/obesity and orthopedic injury in a cohort of Golden Retrievers,, M Simpson , S Albright, et al. This study presents prospectively acquired data demonstrating that gonadectomy is a risk factor for both overweight/obesity and chronic non-traumatic orthopedic injuries in a prospective cohort of Golden Retrievers. Our data suggest that gonadectomy at any age is a risk factor for overweight or obesity, but delaying gonadectomy until dogs are at least 6–12 months of age may help to decrease the risk for orthopedic injury.
- Earlier age at spay/neuter a risk factor in obesity and orthopedic injuries Stewart, P., TL Entriken (2018)
- Prevalence and Risk Factors for Obesity in Adult Dogs from Private US Veterinary Practices EM Lund, PJ Armstrong, et al. (2006)
Urinary Incontinence
Behavior
- Aggression toward Familiar People, Strangers, and Conspecifics in Gonadectomized and Intact Dogs Farhoody, P, MC Zink, et al. (2018)
Dr. Gayle Watkins, PhD is the Founder of Avidog, the leading educational platform for dog breeders and puppy owners, and Gaylan's Golden Retrievers, her 40-year breeding program. Today, Gayle is the only golden retriever AKC Gold Breeder of Merit, and is a three-time AKC “Breeder of the Year.”
