An anthrax outbreak occurred at the Mwea National Reserve between May 2011 and July 2011. This outbreak affected endangered Rothschild’s giraffes (Giraffa camelopardalis ssp. rothschildi). Eleven giraffe carcasses were found during the 3-month period. One lesser kudu (Ammelaphus imberbis), the only one of its species in the national reserve, also succumbed to the illness. An investigation was carried out, and the presence of anthrax was rapidly confirmed using bacteriological methods. To stop the occurrence of more deaths of this endangered