Clinical signs, evaluation of bronchoalveolar lavage fluid, and assessmentof pulmonary function in horses with inflammatory respiratory disease

Objective-To evaluate the association among clinical signs, results of cyto logic evaluation of bronchoalveolar lavage (BAL) fluid, and measures of pul monary function in horses with inflammatory respiratory disease. Animals-9 healthy horses, 5 horses with inflammatory airway disease (IAD), and 9 horses with chronic obstructive pulmonary disease (COPD). Procedures-Clinical examination, lung function tests, and BAL were performe d on each horse. Results-Standard lung mechanics of horses with exacerbated COPD differed si gnificantly from those of healthy horses; however, there were few differenc es among horses with IAD, horses with COPD during remission, and healthy ho rses. Most variables for forced expiration (FE) in horses with COPD or IAD differed significantly from those for healthy horses. Results of clinical e xamination had low to moderate sensitivity and predictive values for a diag nosis of COPD (range, 67 to 80%). Results of FE tests had high sensitivity, specificity, and predictive values for a diagnosis of COPD (79 to 100%), a nd results of standard lung mechanics tests had low sensitivity and predict ive values (22 to 69%). Percentage of neutrophils in BAL fluid was highly s ensitive (100%) but moderately specific (64%) for a diagnosis of COPD. Conclusions and Clinical Relevance-Clinical examination is moderately accur ate for establishing a diagnosis of COPD. Forced expiration tests can speci fically detect early signs of airway obstruction in horses with COPD and IA D that may otherwise be inapparent. Cytologic evaluation of BAL fluid allow s early detection of inflammatory respiratory disease, but it is not specif ic for CORD.