Bacterial and viral pathogens of bovine respiratory disease in veal calves during the first 12 weeks of the fattening period.

Abstract

Pathogens causing bovine respiratory disease (BRD) were investigated during the first 12 weeks of the fattening period at 10 veal farms. Broncho-alveolar lavage samples were taken from 20 calves at arrival, 84 days after arrival and before an antibiotic therapy was used in case of an outbreak of BRD. All samples were tested for viruses: BHV1, PI3, BRSV, BVDV and BCV, and bacteria: M. haemolytica, P. multocida, H. somni, A. pyogenes. At arrival at the farm, 15,7% of the calves had bacteria in their lungs and 26,7% had viruses in their lungs. This percentage increased during outbreaks of BRD. The percentage calves with bacteria in their lungs increased to 60,5% at 12 weeks. P. multocida, PI3 and BCV were most commonly found during the course of the study.