Spaying/neutering risks in large-breed dogs
Dusty Bottoms, an overweight golden retriever in Morris Animal Foundations Golden Retriever Lifetime Study. Photo courtesy of Sean Andersen-Vie

A new study reveals that spaying and neutering large-breed dogs can put them at higher risk for obesity and, in some cases, orthopedic injuries.

New research published in PLOS ONE found that de-sexing large-breed dogs increases their risk of becoming obese and/or suffering from non-traumatic orthopedic injuries. The study was based on health data collected over six years from the Morris Animal Foundation Golden Retriever Lifetime Study cohort of more than 3,000 golden retrievers. Approximately one-half of the dogs in the study had undergone spay or neuter surgery.

“For years, we’ve been taught that spaying or neutering your dog is part of being a responsible pet owner, but there really are advantages and disadvantages to consider when making that decision,” says Dr. Missy Simpson, Morris Animal Foundation epidemiologist and lead author on the paper.

Dr. Simpson found that spayed or neutered dogs were 50% to 100% more likely to become overweight or obese – a risk that didn’t appear to be affected by age. However, the age of the dog at surgery does appear to be a significant factor in non-traumatic orthopedic injuries. Dr. Simpson found that dogs spayed or neutered before six months of age were at a 300% greater risk of sustaining these injuries.

According to Dr. Simpson, the results can likely be applied to other large- and giant-breed dogs besides golden retrievers. To learn more, visit