To Spay or Neuter?

Look at any Facebook post of a dog that has been lost or found and one of the first comments will be spay/neuter your dog. Welfare societies and vets promote spaying and neutering. The health benefits of spaying and neutering are touted as good reasons to be a responsible pet parent. However, no one discusses the negative effects of spaying and neutering and that there are more negative effects than positives especially for male dogs.

I started on the journey of researching spaying and neutering in 2011 when my male dog Themba pictured above (age 2) developed a luxating patella. It was strange for me as he was on a good diet and genetically neither of the parents had displayed this orthopedic issue. Research papers that I read indicated that early neutering and spaying causes bone deformities, cancers etc. The evidence supported what I had read in the research papers available at that time.

As a good pet parent, I had Themba neutered at the age of 9 months, as a giant breed he would only be fully grown at 2 years. Out of 5 brothers out of the same litter the stats are as follows

Dog

Neutered Early Age

Luxating Patella

Bone Cancer

Lymphoma

Life Span

Diet

Themba

9 months

Yes

Yes

No

7 yrs.

Raw

Boris

14 Months

Yes

No

Yes

5 yrs

Pellets

Mitch

No

No

No

No

10.10 yrs

Mixed

Zilla

No

No

No

No

10.8 yrs

Raw

Toshiro

No

No

No

No

11yrs

Raw

 

 

 

 

 

 

 

 

U.C. Davis (de la Riva, Hart et al, 2013) looked at two joint disorders and three cancers– hip dysplasia, cranial cruciate ligament tear, lymphosarcoma, hemangiosarcoma and mast cell tumor– and showed that, for all five diseases analyzed, the disease rates were significantly higher in both males and females that were neutered either early or late compared with intact (non-neutered) dogs.

A study by Zink and colleagues (2014) indicated that gonadectomized  Vizslas had significantly increased odds of developing mast cell cancer, lymphoma, all other cancers, and fear of storms compared with the odds for sexually intact dogs. Brain tumors are 11 times more likely in spayed than intact females (Rzechorzek et al 2019).

Professor Lynette A Hart ( UC DAVIS School of Veterinary Medicine) – “A second focus of recent years has been in collaborating with others in exploring the adverse disease-related effects of spay/neuter in dog as a function of breed membership, gender and neuter age. These three papers, on Golden Retrievers, Labrador Retrievers, and German Shepherds have had a large impact in the veterinary profession and the general public. A major theme concerns differences between breeds and genders. Together with coauthor Benjamin Hart, we have shown that the breeds essential as assistance dogs, military dogs and police dogs-Golden Retrievers, Labrador Retrievers and German Shepherds – all have a marked increased incidence of joint disorders from early spay/neuter that can impact the working life of the dog, and cause major psychological and financial stress for the handler. We have shown that simply avoiding a spay/neuter in the first year can eliminate most of the risks of a joint disorder. The large research team for this work includes several undergraduate students that I have mentored for their own side-piece of research for Animal Biology projects on topics we had not previously examined. These projects are informing our team’s subsequent research on spay-neuter effects including degenerative myelopathy, urinary incontinence, and hypothyroidism. We now are in the final stages of wrapping up information for a single paper on 30+ breeds as well as similar data on five weight classes of mixed breed dogs.”

Dr Bruce Christensen of Kokopelli Assisted Reproductive Canine Services summarizes the contents of the new research paper by Professor Lynette Hart et al below (research paper is still under review)

“An upcoming study, currently under review, out of the Hart lab at UC Davis looked at 35 different dog breeds and assessed various health risks and their association with age of neuter/spay.

Much of the cancer information I have cited in previous posts is from this study. They also looked at joint disorders, specifically hip & elbow dysplasia and cranial cruciate rupture. This study indicates that certain breeds are at much higher risk of experiencing one or more of these debilitating disorders if spayed or neutered, especially at a young age.

While the full details are not yet available, preliminary reports from the Hart group have indicated that St. Bernards neutered/spayed at less than a year of age experience >30% chance of joint disease compared to 5-8% in intact dogs.

Bernese Mountain Dogs jumped from 11% to >30% in females and 4% to 23% in males.

Rottweilers went from 16% to >30% in females and 8% to 22% in males. Even large, mixed-breed dogs went from ≤10% to >20% in females and >15% in males.

The same study, however, did not find any increase in joint disorders in Boxers or female Standard Poodles. Male Standard Poodles showed a modest increase from 2% to 8%. No change was seen in any of the small breed dogs studied (it was low, regardless). Remember that this study only looked at 35 breeds out of the nearly 200 registered AKC breeds, and lumped all mixed breed dogs together. The take-home message is that if you have a large breed dog prone to joint disorders, waiting until at least 12 months of age to spay or neuter will likely reduce the probability of that dog experiencing these crippling disorders later in life. @ Kokopelli Assisted Reproductive Canine Services”

It’s not always possible to keep intact dogs, however if you are going to spay or neuter please try and do so when your dogs is fully grown and ignore the pressure to spay or neuter your dogs at the age of 6 months. There are alternatives such as Ovary Sparing Spay or a Vasectomy which you can discuss with your vet.

For further reading:

https://www.dogsnaturallymagazine.com/health-risks-of-early-spay-neuter/

https://www.parsemus.org/projects/ovary-sparing-spay/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3572183/

https://www.vrcc.com/oncology/does-early-castration-increase-the-risk-of-cancer-in-dogs/#:~:text=The%20authors%20reported%20that%20neutered,be%20extrapolated%20to%20other%20breeds.

https://www.cuvs.org/sites/default/files/inline-files/1-4%20Bentley%20Thalheim%20-%20SpayNeuter.pdf