Which clinical signs are commonly associated with bovine respiratory disease complex (shipping fever)?

• A. Fever, coughing, nasal discharge, depression, tachypnea
• B. Lameness, joint swelling, fever, anorexia
• C. Hyperactivity, weight gain, polyuria, polydipsia
• D. Diarrhea, dehydration, melena

Answer: (A)

Bovine respiratory disease complex, or shipping fever, is a multifactorial illness that develops after stressful events like transport and crowding, which depress the immune system and allow viral and secondary bacterial infections to take hold. The most characteristic signs reflect both the airway and lung involvement and the body’s response to infection. Fever marks the systemic inflammatory response. Coughing indicates irritation and inflammation of the airways, and tachypnea shows increased work of breathing from pneumonia or bronchopneumonia. Nasal discharge arises from mucosal inflammation of the upper and lower respiratory tract, and depression is a common behavior change when cattle feel unwell. Together, these signs form the classic clinical picture of BRDC following shipping stress. Other choices point to problems outside the respiratory system—for example, lameness or joint swelling suggests locomotor disease; polyuria/polydipsia implies endocrine issues; diarrhea with dehydration or melena indicates gastrointestinal processes—so they do not fit the typical BRDC presentation.