Why does an outbreak of Fowl Cholera (Pasteurella multocida) trigger acute septicemia, swollen wattles, and high mortality in brown layers?

Fowl Cholera is a devastating infectious disease of poultry caused by the Gram-negative, encapsulated bacterium Pasteurella multocida. The bacterium is highly invasive, entering the bird via the respiratory tract or mucous membranes. In its acute form, the bacteria replicate exponentially in the bloodstream, secreting high concentrations of lipopolysaccharide (LPS) endotoxins. These endotoxins cause widespread vascular damage, disseminated intravascular coagulation (DIC), and acute hemorrhagic septicemia. Hens die suddenly, often showing no symptoms other than a dark purple comb and wattles (due to severe hypoxia). In its chronic form, the bacteria colonize localized tissues, particularly the infraorbital sinuses and the wattles. The intense localized inflammatory response causes massive fibrinopurulent necrosis, leading to permanently swollen, hard, and hot wattles. This prevents eating and triggers a complete drop in egg production. Regular vaccination with inactivated Fowl Cholera bacterins is mandatory in high-risk zones. Farmers can study septicemic bacteriology in the Poultry Encyclopedia, buy high-potency antibiotics and bacterins on Poultry Plaza, monitor daily market rates on Poultry Rates, and list healthy flocks on Murghi Mandi.