North America is free of the African horse sickness virus, yet this disease poses an important threat should an infected horse or a biting midge that harbors the virus be introduced.

African horse sickness (AHS) is the most lethal disease known to horses. Fortunately for American horses, AHS is currently enzootic, meaning only a limited number of cases occur each year, in sub-Saharan Africa. However incursions into southern Europe, the Middle East, and even the Indian subcontinent occurred in the last century.

“While modified live virus vaccines are available in enzootic countries of sub-Saharan Africa to immunize horses against AHS virus, these vaccines are not licensed in North America and are not problem-free,” reported Alan Guthrie, BVSc, MedVet, PhD, from the University of Pretoria’s Equine Research Centre in South Africa