Neutering may affect health of some dog breeds

UC DAVIS (US) — Neutering or spaying may affect a dog’s risk for developing certain cancers and joint diseases, suggests a new study of golden retrievers.

The study, which examined the health records of 759 golden retrievers, found a doubling of hip dysplasia among male dogs neutered before one year of age. This and other results are published in the journal PLOS ONE.

“The study results indicate that dog owners and service-dog trainers should carefully consider when to have their male or female dogs neutered,” says lead investigator Benjamin Hart, a distinguished professor emeritus in the University of California, Davis School of Veterinary Medicine.

“It is important to remember, however, that because different dog breeds have different vulnerabilities to various diseases, the effects of early and late neutering also may vary from breed to breed,” he says.

While results of the new study are revealing, Hart says the relationship between neutering and disease-risk remains a complex issue.

For example, the increased incidence of joint diseases among early-neutered dogs is likely a combination of the effect of neutering on the young dog’s growth plates as well as the increase in weight on the joints that is commonly seen in neutered dogs.

Dog owners in the United States are overwhelmingly choosing to neuter their dogs, in large part to prevent pet overpopulation or avoid unwanted behaviors. Surgical neutering—known as spaying in females—is usually done when the dog is less than one year old.

In Europe, however, neutering is generally avoided by owners and trainers and not promoted by animal health authorities, Hart says.

During the past decade, some studies have indicated that neutering can have several adverse health effects for certain dog breeds. Those studies examined individual diseases using data drawn from one breed or pooled from several breeds.

Against that backdrop, Hart and colleagues launched their study, using a single hospital database. The study was designed to examine the effects of neutering on the risks of several diseases in the same breed, distinguishing between males and females and between early or late neutering and non-neutering.

The researchers chose to focus on the golden retriever because it is one of the most popular breeds in the US and Europe and is vulnerable to various cancers and joint disorders. The breed also is favored for work as a service dog.

The research team reviewed the records of female and male golden retrievers, ranging in age from 1 to 8 years, that had been examined at the William R. Pritchard Veterinary Medical Teaching Hospital for two joint disorders and three cancers: hip dysplasia, cranial cruciate ligament tear, lymphosarcoma, hemangiosarcoma, and mast cell tumor. The dogs were classified as intact (not neutered), neutered early (before 12 months age), or neutered late (at or after 12 months age).

Joint disorders and cancers are of particular interest because neutering removes the male dog’s testes and the female’s ovaries, interrupting production of certain hormones that play key roles in important body processes such as closure of bone growth plates, and regulation of the estrous cycle in female dogs.

The study revealed 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 dogs.

Specifically, early neutering was associated with an increase in the occurrence of hip dysplasia, cranial cruciate ligament tear and lymphosarcoma in males and of cranial cruciate ligament tear in females. Late neutering was associated with the subsequent occurrence of mast cell tumors and hemangiosarcoma in females.

In most areas, the findings of this study were consistent with earlier studies, suggesting similar increases in disease risks. The new study, however, was the first to specifically report an increased risk of late neutering for mast cell tumors and hemangiosarcoma.

Furthermore, the new study showed a surprising 100 percent increase, or doubling, of the incidence of hip dysplasia among early-neutered males. Earlier studies had reported a 17 percent increase among all neutered dogs compared to all non-neutered dogs, indicating the importance of the new study in making gender and age-of-neutering comparisons.

Source: University of California, Davis

chat5 Comments


  1. Wendy Strin

    My Veterinarian advised getting a Coron de Tulear. He is not aware of many disorders which is one of the reasons he advised me to this breed. Is there any evidence of adverse reaction to neutering my male puppy?
    Wendy Strin

  2. Wendy Strin

    Is there any research about the contraindications in neutering or spaying Coton de Tulear dogs? Our group breeds 100% Malagasy Cotons. The CTCA is run by Dr Jay Russell in New York and brought the dog into the states from Madagasgar in 1977 and is the person responsible for making sure the dogs pass several medical tests at 1 year of age to determine whether or not the dogs are breedable. I’m curious about your research if any has been done with this particular breed.
    Any information would be greatly appreciated.
    Very truly yours,
    Wendy Strin
    (Owner of a female Coton de Tulear, spayed at 6 months)

  3. Dal

    Have u read this?

  4. Steven

    What’s done is done. Enjoy your spayed Coton. And next time get a rescue. There’s too many dogs being killed in shelters already, and breeders just add to the problem.

  5. Warren Gerhardt

    As a chemist but also avid dog rescuer I am either disappointed with this work entirely or with perhaps key omissions in this brief report. It completely overlooks (or does not mention) any diseases or issues that the alteration may improve. It is well known in the rescue community that fixing females to limit excessive breeding reduces breast cancer and/or mastitis issues. Also testicular issue in males is eliminated when the testicles are removed. It seems very one-sided giving only one short line to the societal value of alterations. To the average reader this says avoid alterations ( I am curious as to who funded this work. Come with me into the back of any shelter and look at the hundreds of unwanted dogs, and then come to the area in the way back with all the filled black plastic bags. And as a final note to the breeder up above, you are over supplying a product that the demand is not meeting but instead of having a clearance sale someone else has to do the dirty work and kill the product…get a life and do something to try and make the world a better place instead of stamping out more designer dogs and kvetching about their testicles

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