Avian cholera in common crows, Corvus brachyrhynchos, from the central Texas panhandle

An epornitic of avian cholera involving approximately 150 birds is described from a flock of common crows, Corvus brachyrhynchos, on a single playa lake utilized as a roost in Castro County, Texas, during early spring of 1980. There was a concomitant epornitic of avian cholera involving several hundred ducks and geese of several species on adjacent lakes in he same area. Crows scavenged extensively on waterfowl carcasses. Gross and histopathologic lesions in waterfowl were typical of acute avian cholera. Crows had a more chronic form of the disease, especially neurological involvement with the most common lesion consisting of a hemorrhagic meningitis. Other endemic species from which Pasteurella multocida was isolated included the short-eared owl, Asio flammeus, and cottontail rabbit, Silvilagus sp. The role of crows in the dissemination and maintenance of avian cholera is discussed.