Bovine respiratory syncytial virus (BRSV) is a major cause of lower respiratory tract disease in young calves, causing wheezing, respiratory distress, and significant welfare impact especially in autumn and winter.
Calves with BRSV experience genuine respiratory distress — the effort of breathing through obstructed, inflamed airways is exhausting and uncomfortable. Severe cases breathe with mouths open and necks extended in a classic distress posture. Secondary bacterial pneumonia is painful and can cause lasting lung damage that impairs lifetime performance. BRSV outbreaks often affect multiple calves simultaneously, overwhelming farm and veterinary resources. Prevention through vaccination is far more effective than treatment once disease is established. Reducing stress through thoughtful management of weaning and transport significantly reduces disease incidence, illustrating the connection between good welfare practices and good health outcomes.