Abstract
The first outbreak of fowl cholera occurred in a flock of Muscovy ducks (Cairina moschata) in Okinawa Prefecture of Japan in November 1990. Fifty (25%) of 200 birds in a farm died of an acute disease. Remaining birds recovered after treatment with oxytetracycline. Pasteurella multocida subsp. multocida was isolated in pure culture from all tissues tested from two dead birds. Serovars of the isolates were identified as Carter's capusular type A. Heddleston's type 3·4·12, and Namioka's type 5:A which have not been demonstrated in Japan. Pathologically, multiple necrosis and bacterial aggregates were prominent in several organs, particularly in the liver. The isolate killed chickens when inoculated intravenously at a concentration of 108 colony forming units.
