When does the peak risk for fowl cholera (Pasteurella multocida) outbreaks occur, and when should the flock be vaccinated?

Fowl cholera, caused by the bacterium Pasteurella multocida, is a severe systemic disease that causes high acute mortality, swollen wattles, and respiratory distress in brown layers. Outbreak risks peak during wet, rainy seasons and the hot monsoon months when wild birds, rodents, and standing water act as vectors for transmission. Free-range and deep-litter houses are at highest risk. To build solid immunity before production, flocks must be vaccinated with inactivated fowl cholera vaccines or live attenuated strains, administered first at 8 to 10 weeks of age and boosted at 14 to 16 weeks of age, at least 3 weeks before lay onset. Veterinary treatment protocols are in the Poultry Encyclopedia, high-purity Pasteurella bacterins and broad-spectrum antibiotics are sold on Poultry Plaza, live poultry market rates are updated daily on Poultry Rates, and cholera-free brown layer flocks are listed on Murghi Mandi.