A Canine Distemper Virus Epidemic in Serengeti Lions

This study documented a devastating outbreak of canine distemper virus that killed a large fraction of the lions in the Serengeti ecosystem, demonstrating that infectious disease can cause sudden mass mortality even in a flagship protected population. The authors traced the epidemic, linked it to a virus likely spilling over from domestic dogs in surrounding communities, and described the neurological symptoms and deaths among lions. The episode revealed that lions in protected areas remain vulnerable to pathogens circulating in nearby human-associated animals, a threat invisible until it strikes. The work catalyzed dog-vaccination programs around protected areas and broader attention to disease as a conservation risk for big cats. It matters because it showed that securing habitat and stopping poaching are not enough; disease at the wildlife-domestic interface can imperil even the best-protected populations.