French Bulldogs differ to other dogs in the UK in propensity for many common disorders: a VetCompass study

Abstract

Background The French Bulldog is a highly popular dog breed but is linked with many serious health issues. A holistic view of breed health in French Bulldogs would assist efforts to appreciate the overall health strengths and weaknesses in the French Bulldog and to take appropriate steps to mitigate these. Based on random sampling of French Bulldogs and non-French Bulldogs under primary veterinary care during 2016 within the VetCompass Programme, a cohort study design was used to estimate the one-year (2016) period prevalence of the most commonly diagnosed disorders in each group. Risk factor analysis used multivariable logistic regression modelling methods. Results The analysis included 2,781 French Bulldogs and 21,850 non-French Bulldogs. French Bulldogs were younger (1.51 years, IQR 0.86 – 2.77 vs. 4.48 years, IQR 1.94 – 8.14) (p < 0.001) and lighter (12.45 kg, IQR 11.00 – 14.03 versus 13.80 kg, IQR 8.10 – 25.12) (p < 0.001) than non-French Bulldogs. Of 43 common specific-level disorders across both groups, French Bulldogs had significantly increased adjusted odds of 20/43 (46.5 %) disorders and significantly reduced adjusted odds of 11/43 (25.6 %) disorders compared to non-French Bulldogs. Highly predisposed disorders in French Bulldogs included stenotic nares (OR 42.14; 95 % CI 18.50 to 95.99; p < 0.001), Brachycephalic Obstructive Airway Syndrome (OR 30.89; 95 % CI 20.91 to 45.64; p < 0.001), aural discharge (OR 14.40; 95 % CI 9.08 to 22.86; p < 0.001), skin fold dermatitis (OR 11.18; 95 % CI 7.19 to 17.40; p < 0.001) and dystocia (OR 9.13; 95 % CI 5.17 to 16.13; p < 0.001). At a grouped-level of diagnostic precision, French Bulldogs had increased adjusted odds of 12/32 (37.5 %) disorders and reduced adjusted odds of 6/32 (18.8 %) disorders compared to non-French Bulldogs. Conclusions These results identified ultra-predispositions with worryingly higher odds in French Bulldogs for several disorders, suggesting that the health of French Bulldogs has diverged substantially from, and may be lower than, the health of the wider non-French Bulldog population. Many of these predispositions are closely associated with the conformational extremes that define the French Bulldog breed. Shifting the typical conformation of the French Bulldog population towards a more moderate phenotype is proposed as a logical opportunity to reduce the serious health issues endemic in the French Bulldog breed.

Health of Pug dogs in the UK: disorder predispositions and protections

“…Given that 23/30 (76.7%) of these differences were predispositions rather than protections, this further suggests that divergence from mainstream dog characteristics in Pugs has selected towards greater negative than positive effects for the breed. The results for the French Bulldog, another breed with extreme brachycephaly, were similar to those for the Pug, showing French Bulldogs differed to other dogs in 31/43 (72.1%) of common disorders, showing predispositions in 20/31 (64.5%) and protections in 11/31 (35.5%) [ 32 ]. Studies with similar design to the current study have previously reported that Labrador Retrievers differed to other dogs in 19/35 (54.3%) of common disorders, showing predispositions in 12/19 (63.2%) and protections in 7/19 (36.8%) [ 30 ].…”

“…In the current study, Pugs are reported with 8 ultra-predispositions among 30 common disorders (26.7%). French Bulldogs have previously been reported with a remarkably similar proportion (25.6%), showing 11 ultra-predispositions among 43 common disorders [ 32 ]. Even more remarkable is the finding that 7 of the 8 ultra-predispositions in Pugs are shared as ultra-predispositions in French Bulldogs: BOAS, stenotic nares, corneal ulceration, skin fold dermatitis, aural discharge, allergic skin disorder and demodicosis.…”

“…Since then, a growing and large body of evidence has accumulated on breed predispositions related to conformation in dogs [ 3 , 4 ]. Conversely, the extent of the health differences between a breed and all remaining dogs could be taken as a measure of divergence of that breed from the mainstream of dogs [ 32 ]. With this perspective, the current study suggests that Pugs have diverged substantially from other dogs because Pugs showed differing odds (either predisposition or protection) for 30/40 (75%) of common disorders.…”

“…Deeper understanding of the innate health risks associated with extreme brachycephaly can be gained by comparison of ultra-predispositions between breeds with extreme brachycephaly such as Pugs and French Bulldogs. Ultra-predispositions have been defined as disorders with odds over 4 times higher in a breed compared with all other dogs not of that breed [ 32 ]. Exploration of ultra-predispositions among common disorders offer insights into the key health welfare issues associated that unique breed.…”

“…The data extraction, collation and analytic methods used in this study are deliberately similar to other VetCompass studies in order to promote comparability across the study outputs [ 29 , 30 , 32 ]. The study population included all available dogs under primary veterinary care at 886 clinics participating in the VetCompass Programme during 2016.…”