Cytologic examination of specimens obtained by means of tracheal washes performed before and after high-speed treadmill exercise in horses with a history of poor performance

Objective-To evaluate results of cytologic examination of specimens obtaine d by means of tracheal washes (TW) in 42 horses with a history of poor perf ormance. Design-Cross-sectional case series. Animals-42 horses with a history of poor performance. Procedure-A TW was performed via endoscopy before and after horses exercise d on a high-speed treadmill, and specimens were evaluated microscopically a nd graded. Results-Ten (24%) horses were considered to he clinically normal before and after exercise. Pulmonary hemorrhage was diagnosed in 8 (19%) horses. One horse had evidence of exercise-induced pulmonary hemorrhage (EIPH) before e xercise and pulmonary hemorrhage and allergic or inflammatory airway diseas e (IAD) after exercise. Five (12%) horses had IAD, and 1 had IAD and pulmon ary hemorrhage after exercise. Seven (17%) horses had evidence of EIPH and IAD in both specimens. Four (10%) horses with EIPH had an increase in the p roportion of hemosiderophages in the specimen obtained after exercise. Spec imens obtained before exercise in 6 (14%) horses were not representative of the respiratory tract and could not be compared with specimens obtained af ter exercise. Clinical Implications-Interpretation of TW specimens obtained before and af ter exercise differed for only 5 of 36 (14%) horses. Specimens obtained aft er exercise were more likely to reveal airway disease. All specimens obtain ed after exercise adequately represented the respiratory tract, whereas 6 s pecimens obtained before exercise did not. Specimens obtained after exercis e contained more airway secretions and had less cytologic evidence of phary ngeal contamination. Therefore, we recommend that TW samples be obtained af ter exercise in horses.