Bovine Respiratory Disease (Shipping Fever): Causes, Transmission, and Prevention

Bovine respiratory disease (BRD), commonly called shipping fever, is the leading cause of morbidity and mortality in feedlot cattle. It is a multifactorial syndrome involving viral and bacterial pathogens.

Key Pathogens

• Viruses: Bovine herpesvirus-1 (IBR), BVDV, BRSV, PI3.
• Bacteria: Mannheimia haemolytica, Pasteurella multocida, Histophilus somni, Mycoplasma bovis.

Transmission

• Aerosolized droplets (coughing, sneezing).
• Direct nose-to-nose contact.
• Fomites (contaminated equipment, feed, water, clothing).

Risk Factors (Stressors)

• Transportation, commingling, weaning.
• Weather extremes, dust, poor ventilation.
• Nutritional deficiencies, parasitism.
• Immunosuppression (cortisol from stress impairs immunity).

Clinical Signs

• Fever (> 40°C / 104°F), depression, anorexia.
• Coughing, nasal/ocular discharge, rapid shallow breathing.
• Weight loss, reduced feed efficiency.

Prevention & Control

• Preconditioning: Vaccinate, deworm, wean 30–45 days before shipping.
• Metaphylaxis: Antimicrobial on arrival for high-risk groups (veterinary guidance).
• Biosecurity: Isolation of sick animals, disinfection, all-in/all-out management.
• Environment: Adequate bunk space, clean water, ventilation, dust control.

Early detection and targeted treatment improve outcomes. Work with a veterinarian for herd-specific protocols.