Dog Health Risks from Neutering: Breed Matters

Did you know about the health risks affecting dogs that are neutered? If so, did you know that dog breed can affect the risk level?  Some dog breeds have higher risk of developing certain cancers and joint disorders if neutered or spayed within their first year of life. Until now, studies had only assessed that risk in a few breeds. But now a new study has shed light on the missing information.  A new, 10-year study by researchers at the University of California, Davis, examined 35 dog breeds and found vulnerability from neutering varies greatly depending on the breed. 

When it comes to health risks and the age at which a dog is neutered, there is no “one size fits all” …

“There is a huge disparity among different breeds. Some breeds developed problems, others didn’t. Some may have developed joint disorders but not cancer, or the other way around.”

Dr. Benjamin Hart, distinguished professor emeritus, University of California, Davis, School of Veterinary Medicine

Study overview

In order to understand whether neutering, the age of neutering, or differences in sex when neutered affect certain cancers and joint disorders across dog breeds, researchers analyzed 15 years of data from thousands of dogs examined each year at the UC Davis Veterinary Medical Teaching Hospital. The joint disorders examined include hip dysplasia, cranial cruciate ligament tears and elbow dysplasia. Cancers examined include lymphoma; hemangiosarcoma, or cancer of the blood vessel walls; mast cell tumors; and osteosarcoma, or bone cancer.

Results overview

In most breeds examined, the risk of developing problems was not affected by age of neutering.


Researchers found that vulnerability to joint disorders was related to body size.

“The smaller breeds don’t have these problems, while a majority of the larger breeds tend to have joint disorders.

-Dr. Lynette Hart, professor, UC Davis School of Veterinary Medicine

One of the surprising exceptions to this was among the two giant breeds — Great Danes and Irish wolfhounds — which showed no increased risk to joint disorders when neutered at any age.

Researchers also found the occurrence of cancers in smaller dogs was low, whether neutered or kept intact. However, in two breeds of smaller dogs, the Boston terrier and the shih tzu, there was a significant increase in cancers with neutering.

Another important finding was that the sex of the dog sometimes made a difference in health risks when neutered. Female Boston terriers neutered at the standard six months of age, for example, had no increased risk of joint disorders or cancers compared with intact dogs, but male Boston terriers neutered before a year of age had significantly increased risks.

Previous studies have found that neutering or spaying female golden retrievers at any age increases the risk of one or more of the cancers from 5 percent to up to 15 percent.

Solution for reducing health risks

The study lays out guidelines for pet owners and veterinarians for each of 35 breeds to assist in making a neutering decision. Click here or scroll down to see details in the journal publication below.

Also see: Big dogs face more joint problems if neutered early


Journal Reference: Benjamin L. Hart, Lynette A. Hart, Abigail P. Thigpen, Neil H. Willits. Assisting Decision-Making on Age of Neutering for 35 Breeds of Dogs: Associated Joint Disorders, Cancers, and Urinary Incontinence. Frontiers in Veterinary Science, 2020; 7 DOI: 10.3389/fvets.2020.00388









Ed: KW