Mycobacterium avium-related epizootic in free-ranging lesser flamingos in Kenya

An epizootic in free-ranging lesser flamingos (Phoeniconaias minor) in Keny a resulted in more than 18,500 deaths from August through mid-November 1993 . Disease was concentrated along the shores of Rift Valley Lakes Bogoria an d Nakuru (Kenya) and did not involve any of the other avian or mammalian sp ecies frequenting the lakes. Coincidental to the outbreak was a bloom of al gae on Lake Bogoria, toxins from which were first suspected to be causative . Discrete necrotic and granulomatous lesions were often noted in spleen an d liver, and Mycobacterium avium serovar I was isolated from both organs. E scherichia coli and Pseudomonas aeruginosa also were often recovered in pur e culture from liver. Gross and histopathological evaluation of the cases d isclosed signs of acute sepsis and also chronic, potentially life-threateni ng lesions of mycobacteriosis, primarily involving the spleen and liver. Le sions typical for algae toxicosis were not seen in any birds. Deaths were a ttributed to septicemia, complicated in those affected, by mycobacteriosis.