The French bulldog is everywhere. It’s also one of the most fragile breeds a person can bring home, according to a growing body of veterinary research. A new retrospective study of more than 2,000 French bulldogs adds an important piece to that puzzle: the age at which a dog is spayed or neutered may shape its risk of a painful, sometimes paralyzing spinal condition.
French bulldogs top the charts
French bulldogs have held the top spot on the American Kennel Club’s (AKC) annual breed popularity list for four years. The AKC registered nearly 74,500 French bulldog puppies in 2025 alone, though that number has fallen from a peak of about 108,000 in 2022. Similar trends have occurred in the UK.
Yet, popularity and poor health have risen together. A UK analysis published in 2024 estimated the breed’s median longevity at approximately 9.8 years, making it one of the shortest-lived breeds in that study.
A breed built for trouble
French bulldogs belong to a group of dogs called brachycephalic breeds. The word simply means “short-headed.” Decades of selective breeding gave these dogs their flat faces, big round eyes, and compact bodies. Breeders prize the iconic look, but the dogs may be paying for it with their health.
That same breeding also shortened and compressed the spine. Veterinarians call this body type “chondrodystrophic,” meaning the cartilage that normally guides bone growth develops abnormally. The result is a dog whose skeleton, not just its skull, carries the marks of selective breeding. Vets have linked this body plan to a long list of neurological problems in French bulldogs, including brain tumors, unexplained brain inflammation, and spinal cord disease.
Intervertebral disc herniation, or IVDH, sits near the top of that list. A disc with a soft, gel-like center cushions each vertebra in the spine. In chondrodystrophic breeds, that gel calcifies and hardens years earlier than in other dogs. Trauma or ordinary daily strain can then cause the disc to burst through its outer wall and press against the spinal cord. The result is pain, a wobbly gait, or, in severe cases, paralysis. One 2017 study found IVDH caused 70% of all spinal cord disease diagnosed in French bulldogs at a single referral hospital.
Is gonadectomy related to disc herniation?
A team led by veterinary researchers in Italy was interested in understanding whether gonadectomy (spaying or neutering) was associated with the incidence of IVDH in French bulldogs. They reviewed medical records from 2,101 French bulldogs treated at Italian veterinary clinics between 2019 and 2025. This was a retrospective study, meaning the researchers reviewed existing records rather than conducting a controlled experiment. That design has a real limitation: it can show that two things are linked, but it cannot prove that one causes the other.
Of the dogs studied, 601 had been diagnosed with IVDH using MRI scans, and 1,500 had not. The team split the groups by reproductive status: intact, gonadectomized before 12 months of age (early), or gonadectomized after 12 months of age (late).
Striking differences between males and females
The results split sharply along sex lines. In males, the timing of gonadectomy was important. Dogs neutered before 12 months were nearly twice as likely to develop IVDH as intact males, with an odds ratio of 1.92. Odds ratio is simply a way of comparing risk between two groups; a ratio of 1.92 means the risk was roughly double. Males neutered later actually showed a lower risk than intact males.
In females, the pattern was far stronger. Spayed females faced roughly five times the risk of intact females. Females spayed before 12 months showed nearly a tenfold increase in risk (odds ratio, 9.84) compared with intact females. Even females spayed later still carried close to three times the risk. These are large, striking differences, though the study’s authors describe them as preliminary and call for more research to confirm the pattern.
Interpreting the findings on French bulldogs
The study doesn’t prove that spaying or neutering causes IVDH. It shows a strong statistical association, which the authors link to the endocrine system. Sex hormones like estrogen and testosterone appear to help protect the spinal discs while a puppy’s skeleton is still growing. Removing those hormones early may interfere with that process.
Earlier research supports this concept. Similar patterns have been observed in Dachshunds, another chondrodystrophic breed. Early neutering was also associated with a higher IVDH risk, and females were more highly affected by gonadectomy than males.
The findings also don’t mean owners should skip sterilizing their dogs altogether. Gonadectomy entails risks and benefits, and consideration of a hormone-sparing sterilization method might be a good alternative. The researchers call for a personalized approach that weighs a dog’s breed, sex, and individual health needs.
The takeaway for owners
If you own or are considering a French bulldog, this study is a good reason to talk with your veterinarian about the timing and type of sterilization that’s best. The decision involves real tradeoffs between reproductive health risks and orthopedic or neurological risks. Those tradeoffs differ by sex and by breed. A vet familiar with brachycephalic and chondrodystrophic breeds can weigh those factors against your dog’s specific situation.
The bigger picture is harder to ignore. French bulldogs are wildly popular and, by multiple measures, quietly fragile. This study doesn’t settle every question about why. It does add one more data point suggesting that how we manage these dogs, not just how we breed them, matters for their long-term health.
