title: Bronchial collapse during bronchoalveolar lavage in horses is an indicator of lung inflammation.
abstract: BACKGROUND
  The bronchoalveolar lavage (BAL) procedure can return variable volumes of fluid, possibly depending on the presence of bronchial collapse during fluid aspiration and on the severity of lung inflammation.
  
  
  OBJECTIVE
  We tested the hypothesis that horses with bronchial collapse during BAL are at higher risk of having severe lung inflammation.
  
  
  METHODS
  Prospective field study.
  
  
  METHODS
  Bronchial collapse was graded using a new simple scoring method (0, 1 or 2) during a standardised BAL procedure in the field on 131 horses with normal, mild/moderate or severe lower airway inflammation on cytology of BAL fluid.
  
  
  RESULTS
  Of the 131 horses, 37 (28%), 55 (42%) and 39 (30%) horses had bronchial collapse scores of 0, 1 and 2, respectively. There was a difference in collapse scores between all the BAL inflammation categories (P<0.001). Severe collapse had a positive predictive value of 0.95 for both mild/moderate and severe BAL inflammation, with a prevalence of 63% and 20%, respectively. The BAL fluid return volume in the horses with severe collapse scores was lower than volumes in the partial (score 1/2) and no collapse (score 0/2) groups (P<0.001). The BAL fluid volume was negatively correlated with BAL neutrophil percentage (P<0.001).
  
  
  CONCLUSIONS
  Airway collapse during BAL is associated with airway inflammation and neutrophilia.
  
  
  CONCLUSIONS
  During a standardised BAL procedure, clinicians can expect lung inflammation in horses that have bronchial collapse and bronchial collapse in horses with lung inflammation. Lung inflammation may be a contributing factor in the mechanism of bronchial collapse during BAL in horses.
authors.affiliation: Moore Equine Veterinary Center, Alberta, Canada.
authors.forename: K
authors.initials: K
authors.lastname: Koblinger
authors.forename: K
authors.initials: K
authors.lastname: Hecker
authors.forename: J
authors.initials: J
authors.lastname: Nicol
authors.forename: A
authors.initials: A
authors.lastname: Wasko
authors.forename: N
authors.initials: N
authors.lastname: Fernandez
authors.forename: R
authors.initials: R
authors.lastname: Léguillette
mesh_terms: D000375:Aging; D000822:Animal Husbandry; D000818:Animals; D001980:Bronchi / Q000473:pathology*; D018893:Bronchoalveolar Lavage / Q000009:adverse effects / Q000662:veterinary*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D006734:Horse Diseases / Q000175:diagnosis* / Q000473:pathology; D006736:Horses; D007249:Inflammation / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D008171:Lung Diseases / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*
keywords: bronchi; bronchoalveolar lavage; endoscopy score; horse; inflammation