Equine influenza causes significant acute respiratory illness and requires careful management to prevent welfare harm and disease spread in horse populations.
Equine influenza welfare impacts span acute disease suffering and the consequences of inadequate recovery management. The fever, respiratory effort, and lethargy of acute influenza cause genuine suffering over 7-14 days. Horses forced back into work before respiratory recovery — common when competition commitments create financial pressure — develop secondary complications including bacterial pneumonia that significantly worsen welfare outcomes. Vaccination prevents clinical disease in most vaccinated horses and dramatically reduces transmission in vaccinated populations. The welfare case for universal vaccination in competition horses is strong; outbreaks in unvaccinated or under-vaccinated populations cause widespread preventable suffering. Appropriate rest following clinical recovery is equally important welfare management that requires owner compliance with veterinary guidance over commercial pressure.