Equine infectious anemia (EIA), a lifelong viral disease similar to HIV in humans, is spreading unevenly worldwide, with particularly high prevalence in parts of Mexico, Central and South America, and emerging cases in northern Canada. The virus, transmitted mainly by flies and contaminated veterinary equipment, causes symptoms like fever and anemia in horses and can remain hidden for years, making detection and control challenging. Despite low prevalence in the U.S., Canada, Europe, and parts of Asia, climate change and international horse movement risk expanding its range. Current management often requires euthanasia or lifelong quarantine of infected horses, with no effective vaccine available.

A comprehensive 24-year global review of over 28.5 million equids revealed significant gaps in surveillance, especially in Africa and Oceania, and highlighted the need for coordinated international efforts to improve monitoring, research, and control strategies. Researchers emphasize collaboration among countries to develop better tools, including vaccines, and to address the disease’s spread driven by climate shifts and inconsistent control measures. An international scientific alliance has been formed to advance this fight against EIA, underscoring the urgency of global cooperation to prevent further outbreaks.