ABILITY OF BRONCHODILATORS TO PREVENT BOVINE EXPERIMENTAL RESPIRATORY-DISTRESS

This cross-over trial involving 6 Blue Belgian double-muscled calves a imed to investigate whether ipratropium bromide inhaled alone or in co mbination with clenbuterol hydrochloride could prevent the dramatic cl inical and pulmonary disturbances that are observed during an experime ntally induced bronchoconstriction. Inhaled bronchodilators significan tly influenced the clinical and functional responses of bovines subjec ted to a 5-hydroxytryptamine perfusion. However, despite a mean (stand ard error) wash-out period of 11.2 (3.1) and 7.5 (0.9) d after the 1st and the 2nd one-day challenges, respectively, first-order carry-over effects (ie those remaining from the previous treatment), effects of t he period during which the treatment was allocated and interaction eff ects did not allow a definitive interpretation of overall treatment di fferences.