SUMMARY
Effects of furosemide, exercise, and atropine on tracheal mucus transport rate (tmtr) in horses were investigated. Atropine (0.02 mg/kg of body weight) administered iv or by aerosolization significantly (P < 0.05) decreased tmtr at 60, but not at 30 minutes after its administration in standing horses. Furosemide (1.0 mg/kg, iv) did not have any significant effect on tmtr when measured at 2 or 4 hours after its administration in standing horses. Exercise alone or furosemide (1.0 mg/kg, iv) administration followed 4 hours later by exercise did not alter tmtr, compared with values for standing control or exercised horses administered saline solution. Atropine (0.02 mg/kg, iv) administered after exercise significantly (P < 0.05) decreased tmtr, compared with values for no exercise standing controls, for exercise after administration of saline solution, and for furosemide and exercise.
