A happy Tibetan Mastiff puppy

A happy Tibetan Mastiff puppy (Photo by One Guy on Shutterstock)

DAVIS, Calif. — It’s a question that has long divided dog owners and vets – when is the best time to spay or neuter your dog? An updated study from researchers at the University of California-Davis provides some fresh guidance. The study looked at the connection between neutering age and the risk of certain cancers and joint disorders across 40 popular dog breeds. While all dog breeds are a little different, one of the main conclusions is that undergoing these procedures too early can be harmful to a dog’s long-term health.

The findings, in a nutshell

The findings, published in Frontiers in Veterinary Science, reveal that there is no one-size-fits-all answer. The optimal neutering age can vary quite a bit between breeds and by the dog’s sex. For example, the researchers found that male German shorthaired pointers and female Newfoundlands faced higher risks of joint issues like hip dysplasia if neutered too young. Meanwhile, female Rhodesian ridgebacks were more prone to mast cell tumors with very early neutering before six months-old.

The takeaway? Owners should work closely with their vet to make a personalized neutering decision based on their dog’s breed, sex, and living situation. Delaying neutering until a bit older may reduce future health risks for many breeds. But that has to be balanced against other factors like preventing the birth of unwanted litters.

While all dog breeds are a little different, one of the main conclusions of the new study is that spaying or neutering dogs too early can be harmful to their long-term health. (Photo by Jametlene Reskp on Unsplash)

How did scientists come up with these guidelines?

To arrive at their breed-specific neutering recommendations, the UC Davis team undertook a decade-long process that started with an intriguing 2013 study. It found early neutering elevated risks of joint disorders and cancers in golden retrievers.

Recognizing the wide-ranging differences across breeds, the researchers then spent years digging through records from the university’s veterinary hospital. Their goal? Uncover correlations between neutering age and disease rates in as many popular breeds as possible.

For their latest analysis, they focused on German shorthaired pointers, mastiffs, Newfoundlands, Rhodesian ridgebacks, and Siberian huskies — all larger breeds over 44 pounds. By scrutinizing the medical charts of over 1,200 dogs treated from 2000 through 2020, they could compare incidence rates of joint issues like hip dysplasia or cancers like lymphoma between neutered and intact dogs of different ages.

It was a painstaking process but one that produced valuable insights. For instance, while Siberian huskies showed no significant neutering effects, their results revealed spaying female Newfoundlands before their first birthday markedly increased their joint disorder risk. Although it’s far from the final word, this research aims to better inform owners and enable more personalized neutering decisions to maximize their beloved companions’ health and longevity.

What do the researchers say?

“This is a shift from a long-standing model of early spay/neuter practices in the U.S. and much of Europe to neuter by 6 months of age, but important to consider as we see the connections between gonadal hormone withdrawal from early spay/neuter and potential health concerns,” says Professor Lynette Hart from the School of Veterinary Medicine, in a university release.

“We’re invested in making contributions to people’s relationship with their animals,” adds Benjamin Hart, a distinguished professor emeritus at the School of Veterinary Medicine. “This guidance provides information and options for veterinarians to give pet owners, who should have the final decision-making role for the health and well-being of their animal.”

The research received funding from the Center for Companion Animal Health, but was primarily conducted by the study authors, who were volunteers.

About Chris Melore

Chris Melore has been a writer, researcher, editor, and producer in the New York-area since 2006. He won a local Emmy award for his work in sports television in 2011.

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