MUNICH, Germany, Aug. 12 -- The Max Planck Society issued the following news: * * * Pathogen discovered in 4,000-year-old sheep tooth Livestock played a role in prehistoric plague infections To the point * Role of livestock in spreading the plague: Yersinia pestis has been identified in a 4,000-year-old sheep, indicating that livestock played a role in spreading an early form of plague that once circulated throughout Eurasia during the Late Neolithic and Bronze Age (LNBA) periods. * Spillo  more