OSCILLATORY MEASUREMENTS, BLOOD-GAS ANALYSIS AND CLINICAL OBSERVATIONS AFTER INTRAVENOUS CLENBUTEROL ADMINISTRATION IN HEALTHY AND ACUTELY PNEUMONIC CALVES

The effects of clenbuterol (Ventipulmin, Boehringer Ingelheim) on resp iratory functions were investigated in 6 calves aged 4-6 weeks prior t o and after experimental infection with Pasteurella haemolytica Al. On days 1-3 (prior to infection) and on days 7-9 (after infection), bloo d gas analysis, monofrequency forced oscillation techniques and clinic al examinations (heart rate, respiratory rate) were conducted for 135 min after the intravenous administration of clenbuterol (0.8 mug/kg bo dy weight). In healthy calves prior to Pasteurella infection, intraven ous administration of clenbuterol induced a mild tachycardia and a red uction in the mean oscillatory respiratory resistance. Using the same dose of clenbuterol in diseased calves after infection, the statistica lly significant reduction in oscillatory respiratory resistance was mo re impressive and it was accompanied by a significant increase in the oxygen pressure of the arterialized blood. Heart rate and respiratory rate did not change significantly after the administration of clenbutc rol in infected calves.