Preliminary data were presented at the 22nd Veterinary and Comparative Respiratory Society Symposium in Montreal, QC in 2004.
Association between Cough and Cytology of Bronchoalveolar Lavage Fluid and Pulmonary Function in Horses Diagnosed with Inflammatory Airway Disease
Article first published online: 28 JUN 2008
Copyright © 2008 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 22, Issue 4, pages 1022–1028, July–August 2008
How to Cite
Bedenice, D., Mazan, M.R. and Hoffman, A.M. (2008), Association between Cough and Cytology of Bronchoalveolar Lavage Fluid and Pulmonary Function in Horses Diagnosed with Inflammatory Airway Disease. Journal of Veterinary Internal Medicine, 22: 1022–1028. doi: 10.1111/j.1939-1676.2008.0109.x
- Issue published online: 4 JUL 2008
- Article first published online: 28 JUN 2008
- Submitted July 24, 2007; Revised November 16, 2007; Accepted March 10, 2008.
- Airway hyper-responsiveness;
- Forced oscillation technique;
- Histamine challenge;
- Recurrent airway obstruction
Background: The objective of this study was to examine the relationship between chronic cough, pulmonary mechanical function, bronchial hyper-responsiveness, and peripheral airway inflammation in adult performance horses with nonseptic inflammatory airway disease (IAD).
Hypothesis: We hypothesized that horses with a presenting complaint of cough have a higher percentage of inflammatory cells on bronchoalveolar lavage (BAL), greater airway obstruction, and airway hyper-responsiveness (AHR) than do horses without cough.
Animals/Sample Population: Adult performance horses (n = 137) referred for evaluation of signs of IAD including cough or exercise intolerance (university hospital patients) and BAL samples (n = 142) taken in first opinion practice.
Methods: A descriptive, retrospective cohort analysis was performed to evaluate the association between chronic cough and pulmonary mechanical function, AHR, BAL cytology, patient signalment, and comorbid features (multivariable logistic regression).
Results: Cough was significantly more prevalent in horses >7 years, and best characterized by a high BAL neutrophil count (>5%) and nasal discharge. Lung function mechanics, abnormal thoracic auscultation, and exercise intolerance did not retain statistical significance in the logistical regression analysis of cough. Although AHR was not related to neutrophilic airway inflammation (BAL neutrophils >5%), it was significantly associated with BAL mast cells >2%.
Conclusions and Clinical Importance: Our data support that neutrophilic airway inflammation may potentiate cough without further changing respiratory mechanical function in IAD. In contrast, mast cell release increased AHR without affecting the incidence of cough. Cough may be used as an indicator of neutrophilic airway inflammation in the presence of low-grade nonseptic respiratory disease.