Equine influenza causes significant respiratory illness in horses. Vaccination programs prevent disease welfare impacts and protect both individual horses and herd health.
Equine influenza causes welfare impacts ranging from moderate respiratory illness to severe debilitation in inadequately vaccinated horses. The high fever, persistent cough, and profound lethargy of influenza represent significant suffering that vaccination prevents. The post-illness period — when horses must rest for extended periods to allow full respiratory recovery — is itself a welfare consideration for horses that derive psychological benefit from work and social interaction within managed equine environments. Outbreaks in unvaccinated or inadequately vaccinated populations can spread with extraordinary speed in social horse environments. The welfare case for consistent, correctly-timed vaccination is clear — it prevents suffering that is otherwise entirely preventable. Vaccination scheduling must account for competition restrictions and be coordinated with herd management.