Equine influenza is a highly contagious respiratory disease that spreads rapidly through horse populations. Vaccination is the cornerstone of prevention and outbreak management.
Equine influenza causes significant suffering — affected horses experience fever, profound weakness, painful coughing, and respiratory distress. Complications including secondary bacterial pneumonia can be life-threatening. Return to work too soon after infection causes exercise-induced pulmonary haemorrhage and long-term respiratory compromise. The welfare and economic case for vaccination is compelling — vaccinated horses either avoid infection or experience significantly milder illness. Outbreaks in unvaccinated populations spread rapidly due to the high contagiousness of the virus, affecting large numbers of horses in a short time. Regular booster vaccination is a basic welfare obligation for any horse in contact with others.