title: Evaluation of variations in bronchoalveolar lavage fluid in horses with recurrent airway obstruction.
abstract: OBJECTIVE
  To determine variations in cytologic counts of bronchoalveolar lavage (BAL) fluid attributable to month of collection, first and second aliquots, and left and right lung sites in horses with recurrent airway obstruction (RAO).
  
  
  METHODS
  5 horses with RAO and 5 healthy horses without respiratory tract disease.
  
  
  METHODS
  Horses were housed in a stable for 5 months prior to and throughout the study. Bronchoalveolar lavage fluid was collected from the right and left lung of each horse 3 times at monthly intervals (February, March, and April). Each BAL fluid collection was performed by use of 2 incremental instillations of 250 mL of isotonic saline (0.9% NaCl) solution in the same bronchial site. Analysis of BAL fluid included volume of BAL fluid recovered, a CBC, and differential cytologic counts.
  
  
  RESULTS
  Volume of BAL fluid recovered and cytologic counts did not differ in horses with RAO across time or between right and left lungs, except for the number of mast cells. Horses with RAO had significantly lower volumes of BAL fluid recovered, significantly lower percentages of macrophages and lymphocytes, and significantly higher percentages of neutrophils than did healthy horses. Despite individual variation, all horses with RAO had > 25% neutrophils throughout the study period.
  
  
  CONCLUSIONS
  Despite variation among horses, BAL fluid cytologic counts were repeatable over short and long periods and samples can be used for longitudinal studies as a diagnostic tool of pulmonary inflammation in horses with RAO.
authors.affiliation: Département de Sciences Cliniques, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, QC J2S 7C6, Canada. daniel.jean@umontreal.ca
authors.forename: Daniel
authors.initials: D
authors.lastname: Jean
authors.forename: André
authors.initials: A
authors.lastname: Vrins
authors.forename: Guy
authors.initials: G
authors.lastname: Beauchamp
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Lavoie
mesh_terms: D000402:Airway Obstruction / Q000503:physiopathology / Q000662:veterinary*; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology*; D002452:Cell Count / Q000662:veterinary; D005260:Female; D006734:Horse Diseases / Q000175:diagnosis / Q000503:physiopathology*; D006736:Horses; D008137:Longitudinal Studies; D008168:Lung / Q000166:cytology; D008214:Lymphocytes / Q000276:immunology; D008407:Mast Cells / Q000276:immunology; D009504:Neutrophils / Q000276:immunology; D011014:Pneumonia / Q000175:diagnosis / Q000503:physiopathology / Q000662:veterinary*; D015203:Reproducibility of Results