Traces of bird flu in horses found in Mongolia

Research published in Emerging Infectious Diseases, a journal of the Centers for Disease Control and Prevention (CDC), has revealed the presence of 9 horses with signs of avian influenza (A/H5N1) infection in Mongolia. The study analysed serum collected between July 2021 and October 2023 from animals belonging to 24 herds in different areas of the Asian country. Of the 997 animals tested, 9 had antibodies to the H5N1 virus. According to the researchers, the infections did not cause any particular symptoms or leave any lasting effects on the animals’ health. In any case, the findings show the susceptibility of horses to H5N1 infection and the frequency of spillover events, the research authors explain. The researchers fear that the mixing of cattle already infected with the H5N1 virus and horses could lead to the emergence of a new pathogen resulting from the mixing of the H3N8 equine influenza virus (the subtype circulating in horses) and the H5N1 avian influenza virus. In North America, which is home to 30% of the world’s horse population, cross-breeding between different species is very common in agricultural contexts.