Fowl cholera is caused by the gram-negative non-motile bacterium Pasteurella multocida. P. multocida subspecies multocida is the main cause of fowl cholera, although occasional outbreaks are caused by subspecies septica or gallicida. Fowl cholera occurs in most avian species and is contagious; turkeys are very susceptible, with infections frequently resulting in high mortality in a flock. 7 Fowl cholera is frequently seen as an acute septicemic disease with high mortality and gross anatomic lesions resulting from vascular disturbances. Other domesticated farm animals are carriers and can shed P. multocida; strains vary in virulence for avian species. 10 Once infection occurs, birds may succumb in the acute septicemic phase, may survive the acute phase and succumb in the days following, may become chronically infected, or may ultimately recover. 7 P. multocida can enter the host through the mucous membranes of the upper respiratory tract, conjunctiva, and cutaneous wounds. 7 Stressors, such as changes in environment, nutrition, and injury, can affect the course of the disease. Chronically infected carrier and convalescent birds are a major source of infection because carrier birds shed the bacteria for life. 7 Chronic conditions can occur in which localized infections predominate. 7,9,14 P. multocida can survive in the environment for up to 2 wk and in dried blood for up to 8 d. 7 If separated from organic material, P. multocida is destroyed easily by common disinfectants, sunlight, drying, and at temperatures >56°C. 7 3850V DIXXX10.1177/1040638718823850Fowl cholera and heart rupture in a turkeyBlakey et al.