Fowl cholera is a contagious bacterial disease of domesticated and wild avian species caused by infection with Pasteurella multocida. It typically occurs as a fulminating disease with massive bacteraemia and high morbidity and mortality in older birds. Chronic infections

of birds and is distributed world-wide. Fowl cholera outbreaks often manifest as acute fatal septicaemia, primarily in adult birds. Chronic and asymptomatic infections also occur. Diagnosis depends on isolation and identification of the causative bacterium, Pasteurella multocida. Presumptive diagnosis may be based on the occurrence of typical signs and lesions and/or on the microscopic demonstration of myriad bacteria in blood smears, or impression smears of tissues such as liver or spleen. Mild or chronic forms of the disease also occur where the disease is endemic, with localised infection primarily of the respiratory and skeletal systems.