Equine Influenza is widespread and occurs with variable frequency depending on the region and implementation of vaccination programs. Outbreaks are most common in areas with dense equine populations and frequent horse movement, such as during competitions and transportation for breeding. The disease often strikes in waves, and although vaccination provides some protection, new virus strains can cause periodic epidemics. Surveillance studies indicate that EI is endemic in many parts of the world, particularly affecting unvaccinated equine populations.

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The economic implications of Equine Influenza are substantial. The financial burden includes direct costs, such as veterinary treatment, quarantine measures, and vaccination programs, and indirect costs like lost performance and competition opportunities. A study analyzing the 2007 Equine Influenza outbreak in Australia, where the virus spread due to biosecurity breaches, estimated total economic losses at approximately AUD 1 billion. The outbreak led to widespread cancellations of equestrian events, movement bans, and the temporary shutdown of the racing industry.