Efficacy of tulathromycin or enrofloxacin for initial treatment of naturally occurring bovine respiratory disease in feeder calves.

After undergoing arrival processing at one of two commercial feedlots, feeder calves with clinical signs of bovine respiratory disease (BRD) were randomly assigned to receive either tulathromycin (2.4 mg/kg SC) or enrofloxacin (12.5 mg/kg SC).