A canine distemper virus epidemic in Serengeti lions (Panthera leo)

This landmark study documented the catastrophic 1994 canine distemper virus (CDV) outbreak that killed roughly a third of the Serengeti lion population, an estimated 1,000 lions, along with leopards, bat-eared foxes and spotted hyenas. Researchers combined serology, virus isolation, clinical observation of seizures and neurological signs, and necropsy to confirm CDV as the cause of mass mortality. Phylogenetic analysis tied the lion virus to a morbillivirus circulating in the surrounding domestic dog population, implicating dogs as a likely reservoir. The work was pivotal because it showed a pathogen long associated with dogs could devastate a large wild felid population, reframing how conservationists think about multi-host disease at the domestic-wildlife interface and motivating dog vaccination cordons around protected areas.