When it is desired to identify infectious agents involved in an outbreak of bovine respiratory disease, a variety of possible sampling methods may be used. For field use, the deep nasopharyngeal swab, transtracheal wash, and nonendoscopic bronchoalveolar lavage are most feasible. At present, bacterial culture and polymerase chain reaction testing are most commonly used to identify infectious agents. Interpretation of test results can be challenging, particularly for opportunistic pathogens. Evidence-based guidelines for precise interpretation of microbiologic tests results are lacking; however, approaches that have been practically useful for the management of bovine respiratory disease outbreaks are presented.
Bovine Respiratory Disease Diagnosis: What Progress Has Been Made in Infectious Diagnosis?