Bovine Respiratory Syncytial Virus: Welfare Impact and Prevention

Bovine respiratory syncytial virus (BRSV) is a major component of the bovine respiratory disease complex causing severe respiratory distress and significant welfare harm, particularly in young stock.

Key Facts

BRSV is a primary pathogen causing severe lower respiratory disease in calves under 6 months
Clinical signs include acute respiratory distress, fever, nasal discharge, and hypoxia
BRSV causes particularly severe alveolar damage leading to emphysema and pneumothorax
Maternal antibodies from colostrum provide partial protection in the first weeks of life
Vaccination programmes significantly reduce the severity and prevalence of BRSV outbreaks

Welfare Considerations

BRSV causes acute severe respiratory distress that represents one of the most immediately welfare-compromising diseases in young cattle. Affected calves struggle to breathe, show open-mouth breathing, and experience hypoxia from damaged alveoli. Emphysema and pneumothorax as complications of severe BRSV cause intense pain and respiratory failure. The acute welfare impact is sudden and severe. Vaccination before the risk period, combined with colostrum management and reduction of respiratory disease risk factors including overcrowding and poor ventilation, significantly reduces BRSV-related welfare harm in susceptible calf cohorts.

What You Can Do

Implement BRSV vaccination programmes targeting calves before the autumn risk period
Ensure all calves receive adequate colostrum for maximum passive immunity
Reduce stocking density and improve ventilation in calf housing to reduce respiratory challenge
Monitor calf respiratory health daily using validated scoring systems during risk periods
Seek prompt veterinary treatment for calves showing acute respiratory distress from BRSV