Avian cholera, also known as fowl cholera, is a bacterial disease that can affect a wide range of bird species. Backyard flock owners should be aware that chickens, turkeys, ducks, and geese can all contract the illness. Older birds tend to be more susceptible than younger birds.
Green, watery diarrhea
Nasal or oral discharge
Avian cholera is caused by the bacteria Pasteurella multocida so antibiotics may be helpful in fighting the infection. Unfortunately, death usually follows so quickly after infection that there usually is no indication that the bird is sick before it is found dead. Also, treating the entire flock preventatively may only lead to P multocida adapting and mutating into resistant strains.
Excellent sanitation is the best way to prevent many illnesses in your flock. Rodent control is important, as rats and mice serve as vectors for the bacteria. Avoid overcrowding to reduce the rate of transmission. A vaccine is available for commercial breeding flocks.