Bovine respiratory disease complex involves multiple viral and bacterial pathogens that together cause the most significant disease welfare burden in beef cattle.
BRD complex causes fever, laboured breathing, and significant pain across the respiratory tract. The cascading nature of the disease - stress immunosuppression enabling viral then bacterial infection - means that welfare improvements in management can prevent much BRD suffering before it starts. Prevention through stress reduction and appropriate vaccination is more welfare-effective than reactive treatment.