For several years, the French Bulldog has been the most registered breed in France and several European countries.

Its commercial success is undeniable, but its medical fragility is just as significant...

Among the pathologies that affect them, locomotor and vertebral problems are among the least publicized. Paradoxically, they are among the best scientifically documented.

This article deals exclusively with the locomotor and vertebral aspects. It does not cover respiratory (brachycephalic syndrome) or ocular pathologies (which will be the subject of other articles.)

It aims to give buyers, owners, and dog professionals an honest picture of what extreme morphological selection (man-made) implies for the locomotion of this breed.

Ryan et al., Journal of Veterinary Internal Medicine, 2017: 62 English Bulldogs

Vertebral malformations: a near-universal reality

The "corkscrew" tail morphology of the French Bulldog is linked to a variant of the DISHEVELED 2 (DVL2) gene, involved in congenital malformations of the caudal vertebrae.

This same variant is also associated, with variable penetrance depending on the breed, with thoracic vertebral malformations (notably hemivertebrae that can contribute to kyphosis or scoliosis of the spine.)

Mansour et al. (2018, PLOS Genetics) identified this DVL2 variant by whole-genome sequencing of 100 dogs.

It is fixed at 100% in English and French Bulldogs and present at 94% in Boston Terriers.

The study by Ryan et al. (2017, Journal of Veterinary Internal Medicine) evaluated 62 neurologically normal French Bulldogs by thoracic CT scan.

Result: 93.5% had at least one hemivertebra (without any clinical signs). This is one of the highest prevalences ever documented for a congenital malformation in a canine breed!

The recent review by De Decker et al. (2024, PubMed 38458418) reminds us that while most of these malformations remain asymptomatic, certain configurations (especially when a hemivertebra is accompanied by marked kyphosis) can be associated with neurological signs. It particularly emphasizes that clinical interpretation depends on the type of malformation, its severity, and the clinical context.

Disc herniation: a specific risk for this breed

Due to its chondrodystrophic morphology (presence of the FGF4 retrogene), the French Bulldog shares with the Dachshund a predisposition to Hansen type I disc herniation (early degeneration and calcification of the intervertebral discs).

The Dog Aging Project (Wee & Nin, JAVMA, 2025), involving 43,517 American dogs, identifies the French Bulldog as the breed with the highest ratios for this disease, even after adjusting for other risk factors.

This is higher than in Dachshunds in adjusted analysis, even though the Dachshund remains the breed with the highest lifetime prevalence in this cohort.

The study by Aikawa et al. (2014, Veterinary Surgery) directly compared thoracolumbar disc herniations in French Bulldogs and Dachshunds: French Bulldogs were significantly younger at the time of surgical treatment than Dachshunds, which reinforces the idea of often early onset in the breed.

Patellar luxation: an additional joint risk

Patellar luxation is also well-documented in French Bulldogs. The epidemiological study by O'Neill et al. (2016, PMC4898461) on 210,824 dogs in primary care in England identifies the French Bulldog among the 4 breeds with the highest risk of patellar luxation, alongside the Pomeranian, Chihuahua, and Yorkshire Terrier.

Its peculiar morphology (broad build, relatively short limbs, atypical angulations) creates mechanical conditions favorable to patellar luxation.

What you can do concretely

• Before purchase: demand spinal imaging (X-rays or CT scan) of both parents (some serious breeders provide it).

• Maintain weight within recommended limits: every extra kilogram aggravates mechanical stress on an already malformed spine and fragile knees.

• Avoid repeated jumping and slippery surfaces: axial shocks on a malformed spine can precipitate vertebral decompensation.

• Regular neurological monitoring: any change in gait, any hind limb weakness, any refusal of usual activity warrants a quick consultation.

• Do not minimize intermittent hind limb lameness: in a French Bulldog, it can signal patellar luxation or incipient disc herniation.

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Sources

1. Ryan R. et al. (2017). Prevalence of thoracic vertebral malformations in French Bulldogs, Pugs, and English Bulldogs, with or without associated neurological deficits. Journal of Veterinary Internal Medicine. PubMed 28283076
2. De Decker S. et al. (2024). Vertebral and spinal malformations in small brachycephalic dog breeds: current knowledge and outstanding questions. Veterinary Journal. PubMed 38458418
3. Wee C., Nin DZ (2025). Demographic and lifestyle factors influence owner-reported lifetime prevalence of intervertebral disc disease (IVDD): 43,517 companion dogs in the United States. Journal of the AVMA, 263(5). PubMed 39813820
4. O'Neill DG et al. (2016). Epidemiology of patellar luxation in dogs seen in general veterinary practice in England. Canine Genetics and Epidemiology. PMC4898461 / PubMed 27280025
5. Aikawa T. et al. (2014). Comparison of thoracolumbar disc extrusion in French Bulldogs and Dachshunds and its association with congenital vertebral anomalies. Veterinary Surgery, 43(3): 301–307. PubMed 24433331
6. Mansour TA et al. (2018). A genomic variant association study in 100 dogs identified a frameshift mutation in the DISHEVELED 2 gene, contributing to Robinow-like syndrome in Bulldogs and related corkscrew-tailed dog breeds. PLOS Genetics, 14(12): e1007850. PubMed 30521570