Why You Might Want to Hold Off on Neutering Your Dog

Think spaying or neutering your dog as a puppy is best for their health? New research says waiting might be safer in the long run.

Every year thousands of unwanted pets are relinquished to shelters, given up by their owners, or put out on the street to fend for themselves. To combat what was seen as a growing epidemic, owners were advised to spay and neuter early—as early as possible, in some cases—to avoid unwanted litters and help combat the pet overpopulation problem facing shelters across the country.

Lately, though, there’s been a trend toward waiting to spay and neuter your pets until they’re a little older. A burgeoning body of research suggests that early spay and neuter surgeries are related to a number of health problems seen in middle-aged and older dogs, and as such are actually mistakes dog owners shouldn’t be making. According to Rachel Eddleman, DVM, of Mt. Yonah Animal Hospital in Cleveland, Georgia, holding off on having your pet altered can preempt a number of medical complaints. “Waiting until your dog is older decreases the likelihood of female urinary incontinence, orthopedic problems including cranial cruciate ligament tears, and certain cancers.”

A study published in PLoS One in July 2019 showed that dogs who had been spayed or neutered were at an increased risk of obesity, as well as non-traumatic orthopedic problems, like tendon and ligament tears and weakening and hip dysplasia. Researchers found that, while all altered dogs are at a higher risk for unhealthy weight gain, delaying spay or neuter surgery until at least six months of age decreased the likelihood of chronic orthopedic issues. Knowing what the most common health problems are for your dog’s breed can help head off and quickly resolve any issues.

Similarly, a study from 2013 performed on a group of Golden Retrievers found that two types of cancer, lymphosarcoma and hemangiosarcoma, were diagnosed more frequently in dogs who had been spayed or neutered early. While the link is still unclear, a study in human women suggests that estrogen may play a role in reducing cancer risks and the removal of the ovaries, as in a spay surgery, removes the ability to produce estrogen in female dogs, and thereby could, in theory, increase the risk of developing certain cancers.

Despite the evidence, the ASPCA still requires pets up for adoption to be altered at two months of age or two pounds of body weight, whichever comes first. Similarly, the majority of states require prospective owners to agree to spay or neuter adopted pets upon adoption. “There’s not a one-size-fits-all best time to spay/neuter,” explains Dr. Eddleman. “While it’s clear that we should wait to spay/neuter for the medical well-being of the pet, some pet parents aren’t ready for a female dog in heat or a male dog’s behavior changes,” she says. “Pet owners should have a conversation with their veterinarian about what will be best for their pet’s well-being and household and what to expect as their dog matures,” she says. Spaying or neutering dogs is one of the 20 things you need to consider before adopting a rescue dog.

Kristi Pahr
Kristi is a freelance writer out of South Carolina, USA. She was a graduate veterinary technician with 10+ years in veterinary medicine before deciding to stay home and raise her children. Since becoming a freelancer, she's been published at several national outlets, including but not limited to Paste Magazine, Bustle, and Romper. She specializes in health and wellness, parenting, mental health, and animal care.