Intervertebral disc herniation (IVDH) is a serious clinical disease for many chondrodystrophic breeds. Understatement of the year, right? Signs can range from pain to complete immobility (paralysis) and have a negative impact on the long-term owner-pet relationship. We have recently observed that there is a genetic component in the French Bulldog, and other chondrodystrophic breeds, which puts them at higher risk than their non-chondrodystrophic breed counter parts. With the increase in Frenchie ownership worldwide authors in Italy recently evaluated the connection between early gonadectomy and the development of IVDH in Frenchies. (Tabbi et al. 2025: “Influence of gonadectomy and age at gonadectomy on the risk of developing intervertebral dis herniation in French Bulldogs: a retrospective study”)
The authors included 2101 dogs: 601 affected (those with clinical IVDH) and 1500 control dogs (those without clinical IVHD). Notably, the dogs in the affected group were required to have a neurologic exam and MRI but NOT the control dogs.
Results
Males that underwent early gonadectomy (less than 12 months of age) had an almost 2x higher odds of developing IVDH. Female dogs that underwent early gonadectomy had an almost 5x higher odds of developing IVDH. Fascinatingly, gonadectomy at any age for a male was not a risk factor; the odds increased only the group which received gonadectomy less than 12 months of age. However, in females both early and late gonadectomy was associated with the development of IVDH however the magnitude increased dramatically when spayed before 12 months of age.
How does this happen? The authors argue that estrogen and testosterone are helpful in skeletal and cartilaginous development. Therefore, early reduction of these hormones can lead to immature development of the annulus fibrosis of the intervertebral disc, leading to herniation.
What are the limitations of this study?
The study is retrospective so causation is difficult to relate. This means that while early gonadectomy was associated with a higher odd of developing IVDH it cannot be linked as a cause. That is a very picky thing to say but I think it’s worth being careful about this data until it can be duplicated or shown in a prospective analysis. The number of gonadectomized males was much lower than females which could have limited their data analysis. That said, the total numbers were robust. Lastly, while I love that they used MRI to confirm the affected group, it is possible that the control group had subclinical disc herniation which was not detected on neurologic examination and an MRI was not performed in this group.
What’s the takeaway?
Perhaps we should consider delayed neutering for male, and possibly female dogs, until skeletal maturity has been reached. If doing that, the outcomes and limitations of this study could be discussed with the owner. Then again, this study needs to be duplicated so it is also reasonable to keep this information tucked into your brain until we get that second study.
Thanks for reading! I hope your start to fall, the school year or whatever comes your way in September has been a good so far. My schedule is very limited through mid-September so please please email me if you cannot find a suitable time on the posted schedule. I’ll do my best to squeeze you in if I can!