Breeding French bulldogs so that they breathe well—A long way to go

Autoři: Eva-Marie Ravn-Mølby aff001;  Line Sindahl aff001;  Søren Saxmose Nielsen aff001;  Camilla S. Bruun aff001;  Peter Sandøe aff001;  Merete Fredholm aff001
Působiště autorů: Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg C, Denmark aff001;  Department of Food and Resource Economics, University of Copenhagen, Frederiksberg C, Denmark aff002
Vyšlo v časopise: PLoS ONE 14(12)
Kategorie: Research Article


Brachycephalic syndrome (BS) is a pathophysiological disorder caused by excessive soft tissue within the upper airways of short-nosed dog breeds, causing obstruction of the nasal, pharyngeal and laryngeal lumen, resulting in severe respiratory distress. As the prevalence of BS appears to be high among some of the affected breeds, there is an urgent need for breeding efforts to improve the health status of those dogs. In the present study, we evaluated correlations between morphometric and other phenotypic characteristics and BS in a population of 69 French bulldogs from Denmark to identify parameters that could serve as a basis for breeding against BS. Furthermore, the genetic variation was monitored to determine whether it would be possible to breed based on these characteristics without simultaneously causing a critical reduction in genetic variation. Six phenotypic characteristics were correlated with the Brachycephalic Syndrome Functional (BSF) score. Among the morphometric risk factors, nostril stenosis (NS) and neck girth (NG) had the highest impact on the BSF score, accounting for 32% and 4% of the variation, respectively. The genetic variation in the population was comparable to other pure breeds, i.e. estimated and observed heterozygosity was 0.60 and the average inbreeding coefficient was 0.01. If only dogs with Grades 1 and 2 NS (no or only mild NS) were selected for breeding the mean BSF score would be reduced significantly. However, it would result in the exclusion of 81% of the population for breeding and this is not prudent. Excluding only dogs with severe stenosis (Grade 4) would exclude 50% of the population without any adverse impact on genetic variation within the population. Although exclusion of dogs with Grade 4 would result in an apparent reduction in the mean BSF score, this reduction is not significant. As NS accounts for 32% of the variation in BSF score, a possible long term strategy to reduce the prevalence of the BS in French bulldogs would seem to be a selection scheme that first excluded dogs with the most severe NS from breeding, gradually moving towards selecting dogs with lower NS grades. According to our findings there is no viable short term solution for reducing the prevalence of BS in the French bulldog population.

Klíčová slova:

Alleles – Dogs – Genetic polymorphism – Heterozygosity – Morphometry – Pets and companion animals – Population genetics – Auscultation


1. Roedler F.S., Pohl S., Oechtering G.U. How does severe brachycephaly affect dog’s lives? Results of a structured preoperative owner questionnaire. The Veterinary Journal. 2013; 198, 606–610. doi: 10.1016/j.tvjl.2013.09.009 24176279

2. Liu N.-C., Troconis E.L., Kalmar L., Price D.J., Wright H.E., Adams V.J., Sargan D. R., Ladlow J.F. Conformational risk factors of brachycephalic obstructive airway syndrome (BOAS) in pugs, French bulldogs, and bulldogs. PLoS ONE. 2017; 12 (8), 1–24.

3. Packer R.M.A., Hendricks A., Tivers M.S., Burn C. Impact of facial conformation on canine health: Brachycephalic obstructive airway syndrome. PLoS ONE. 2015; 10 (10), 1–21.

4. Meola S.D. Brachycephalic airway syndrome. Topics in Companion Animal Medicine. 2013; 28 (3), 91–6. doi: 10.1053/j.tcam.2013.06.004 24182996

5. Packer R.M.A., Tivers M.S. Strategies for the management and prevention of conformation related respiratory disorders in brachycephalic dogs. Veterinary Medicine. 2015; Research and Reports, 6, 219–232. doi: 10.2147/VMRR.S60475 30101109

6. Liu N.-C., Adams V.J., Kalmar L., Ladlow J.F., Sargan D.R. Whole-body barometric plethysmography characterizes upper airway obstruction in 3 brachycephalic breeds of dogs. Journal of Veterinary Internal Medicine. 2016; 30 (3), 853–65. doi: 10.1111/jvim.13933 27159898

7. Agudelo C.F., Schanilec P. Evaluation of the functional capacity in dogs with naturally acquired heart disease. Veterinarni Medicina. 2013; 58 (5), 264–270.

8. Boddy K.N., Roche B.M., Schwartz D.S., Nakayama T., Hamlin R.L., 2004: Evaluation of the six-minute walk test in dogs. American Journal of Veterinary Research, 65 (3), 311–313. doi: 10.2460/ajvr.2004.65.311 15027678

9. Swimmer RA and Rozanski EA. Evaluation of the 6-Minute Walk Test in Pet Dogs. J Vet Intern Med 2011; 25:405–406. doi: 10.1111/j.1939-1676.2011.0689.x 21352372

10. Lilja-Maula L., Laurila H.P., Syrjä P., Lappalainen A.K., Krafft E., Clercx C., Rajamäki M.M. Long-term outcome and use of 6-minute walk test in West Highland white terriers with idiopathic pulmonary fibrosis. Journal of Veterinary Internal Medicine. 2014; 28, 379–385. doi: 10.1111/jvim.12281 24417616

11. Cerda-Gonzalez S., Talarico L., Todhunter R. Noninvasive Assesment og Neuromoscular Disease in Dogs: Use of the 6-minute Walk Test to Assess Submaximal Exercise Tolerance in Dogs with Centronuclear Myopahty. Journal of Veterinary Internal Medicine. 2016; 30, 808–812. doi: 10.1111/jvim.13939 27012153

12. Manens J., Ricci J., Damoiseaux C., Gault S., Contiero B., Diez M., Clercx C. Effect of body weight loss on cardiopulmonary function assessed by 6-minute walk test and arterial blood gas analysis in obese dogs. Journal of Veterinary Internal Medicine. 2014; 28, 371–378. doi: 10.1111/jvim.12260 24351032

13. Lilja-Maula L., Lappalainen A.K., Hyytiäinen H.K., Kuusela E., Kaimio M., Schildt K., Mölsä S., Morelius M., Rajamäki M.M. Comparison of submaximal exercise test results and severity of brachycephalic obstructive airway syndrome in English bulldogs. The Veterinary Journal. 2017; 219, 22–26. doi: 10.1016/j.tvjl.2016.11.019 28093105

14. Riggs J, Liu N-C, Sutton DR, Sargan D, Ladlow JF. Validation of exercise testing and laryngeal auscultation for grading brachycephalic obstructive airway syndrome in pugs, French bulldogs, and English bulldogs by using whole-body barometric plethysmography. Veterinary Surgery. 2019; 48:488–496. doi: 10.1111/vsu.13159 30666670

15. Sutter N.B., Mosher D.S., Gray M.M., Ostrander E.A. Morphometrics within dog breeds are highly reproducible and dispute Rensch’s rule. Mammalian Genome. 2008; 19 (10–12), 713–723. doi: 10.1007/s00335-008-9153-6 19020935


17. Solway S, Brooks D, Lacasse Y, Thomas S. A qualitative systematic overview of the measurement properties of functional walk tests used in the cardiorespiratory domain. Chest. 2001 Jan; 119(1):256–70. doi: 10.1378/chest.119.1.256 11157613

18. Aromaa M, Lilja-Maula L, Rajamäki MM. Assesment of welfare and brachycephalic obstructive airway syndrome signs in young, breeding age French Bulldogs and Pugs, using owner questionnaire, physical examination and walk tests. Animal Welfare. 2019; 28:287–298.

19. Pedersen N., Liu H., Theilen G., Sacks B. The effects of dog breed development on genetic diversity and the relative influences of performance and conformation breeding. Journal of Animal Breeding and Genetics. 2012; 130, 236–248. doi: 10.1111/jbg.12017 23679949

20. Pedersen N.C., Pooch A.S., Liu H. A genetic assessment of the English bulldog. Canine Genetics and Epidemiology. 2016; 6 (3), 1–16.


22. Evans KM, Adams VJ. Proportion of litters of purebred dogs born by caesarean section. J Small Anim Pract. 2010; 51(2): 113–118. doi: 10.1111/j.1748-5827.2009.00902.x 20136998

23. Ryana R, Gutierrez-Quintanab R, ter Haara G, De Decker S. Prevalence of thoracic vertebral malformations in French bulldogs, Pugs and English bulldogs with and without associated neurological deficits. The Veterinary Journal. 2017; 221, 25–29. doi: 10.1016/j.tvjl.2017.01.018 28283076

Článek vyšel v časopise


2019 Číslo 12
Nejčtenější tento týden