Bovine respiratory disease is the most economically important disease in feedlot cattle and a major source of welfare-relevant morbidity and mortality globally.
Bovine respiratory disease causes significant welfare impacts through fever, laboured breathing, reduced appetite, lethargy, and pleuritis. Affected cattle experience days to weeks of illness before responding to treatment. Animals not detected and treated promptly develop chronic pneumonia with permanent lung damage, compromising welfare throughout their productive life. The stress of long-distance transport triggering BRD is a major welfare event, with processing stress at feedlot entry compounding disease risk.