Equine influenza causes significant respiratory illness with welfare impacts on individual horses and epidemic potential in unvaccinated populations, making vaccination programs essential for herd welfare.
Equine influenza causes significant acute welfare compromise through fever, respiratory distress, and prolonged malaise. The highly contagious nature means outbreaks rapidly affect multiple horses in any facility with an unvaccinated individual. Secondary bacterial pneumonia causes severe welfare complications requiring intensive treatment. The 2007 Australian outbreak illustrated dramatically how quickly an influenza epidemic spreads through naive populations, causing industry-wide welfare impacts. Vaccination programs protect individual horses and provide herd immunity that reduces epidemic risk.