Characteristics of fowl cholera diagnosed in Georgia, 1989-91.

One hundred seventy-six cases of fowl cholera were diagnosed at the Georgia Poultry Laboratory over a 3-year period. The disease occurred throughout the year, with peak incidence during March and April. Fowl cholera was diagnosed in flocks from 4 to 83 weeks of age, with a mean of 33 weeks of age. The Pasteurella multocida isolates were highly susceptible to all antimicrobial agents tested, except sulfonamides. The serotypic distribution of isolates showed that serotype 3,4 predominated (40%), followed by serotype 3 (22%), serotype 1 (18%), untypable (15%), serotype 5 (3%), and serotype 4 (2%). Associations were found between the P. multocida serotypes isolated from birds of different ages and between the age of the bird and the sites of choice for isolating the organism.