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

Vet Surg. 2019 May;48(4):488-496. doi: 10.1111/vsu.13159. Epub 2019 Jan 21.


Objective: To determine whether the sensitivity of clinical examination for assessing upper airway disease severity in 3 breeds of brachycephalic dogs can be improved by incorporating an exercise test (ET) or by auscultation of a laryngeal stridor to predict laryngeal collapse.

Study design: Prospective clinical study.

Animals: Client-owned brachycephalic dogs (n = 44 ET; n = 57 laryngeal stridor assessment).

Methods: In the first part of the study, clinical examinations were performed at rest and after 5-minute walk and 3-minute trot tests, and a grade reflective of brachycephalic obstructive airway syndrome (BOAS) severity was assigned. Whole-body barometric plethysmography was used as a comparative, objective measure of disease severity. In the second part of the study, the degree of laryngeal collapse present in dogs undergoing BOAS surgery was compared to pre-exercise and postexercise laryngeal stridor detected during functional testing.

Results: The sensitivity of clinical examination for BOAS diagnosis was 56.7% pre-ET, 70% after a 5-minute walk test, and 93.3% after a 3-minute trot test. The sensitivity of laryngeal stridor as a predictor of laryngeal collapse was improved after exercise (70%) compared with before exercise (60%). Specificity of laryngeal stridor for laryngeal collapse was 100% (pre-exercise and postexercise).

Conclusion: The sensitivity of clinical examination for BOAS diagnosis was improved by inclusion of an ET, particularly the 3-minute trot test. Audible laryngeal stridor was highly specific but only moderately sensitive for laryngeal collapse.

Clinical significance: Inclusion of a 3-minute trot test and careful auscultation for laryngeal stridor are recommended during BOAS assessment of brachycephalic dogs.

MeSH terms

  • Airway Obstruction / pathology
  • Airway Obstruction / veterinary*
  • Animals
  • Auscultation
  • Craniosynostoses / veterinary
  • Dog Diseases / diagnosis*
  • Dogs
  • Exercise Test
  • Female
  • Larynx / pathology*
  • Male
  • Physical Conditioning, Animal
  • Plethysmography, Whole Body / veterinary*
  • Prospective Studies
  • Reproducibility of Results