Pullorum disease (PD), also referred to as bacillary white diarrhea, is an acute septicemic disease affecting primarily chickens and turkeys. It is caused by the
Salmonella enterica subsp.
enterica Gallinarum-Pullorum bacterium. It is one of several different diseases that are collectively referred to as
Salmonellosis. PD rarely occurs in commercial poultry anymore, however it is quite common in backyard flocks.
PD primarily affects young chicks, between 2 to 3 weeks old. Chicks that were passed the bacteria vertically from the breeder birds, usually will begin to develop clinical signs within a couple weeks upon hatching. Chicks may be seen huddling under heat sources, making continuous faint chirping and peeping noises, weakness, loss of appetite, poor growth, difficulty breathing, and droopy wings. Affected chicks will have white chalky diarrhea pasted to their vents ('pasted butt'). The diarrhea can quickly lead to dehydration, and the accumulation on the vent can potentially cause a blockage unless it is cleaned off so chicks can continue to defecate.
Many chicks will not survive the course of the disease. Some chicks may recover, however they will remain carriers of
S. pullorum, and during times of stress may shed the bacteria in their feces. If the chickens are used for breeding or egg laying purposes, they will pass
S. pullorum vertically through their eggs, and to their offspring or to people that may consume the eggs.
In the United States, many commercial chicken breeders participate in the
National Poultry Improvement Plan (NPIP). The program was established in the early 1930s to coordinate State programs aimed at eliminating PD and other egg-transmitted diseases of chickens and other poultry, to offspring. Flocks that participate in NPIP are required to conduct periodic blood testing on adult breeding birds, to ensure that they aren't carriers.
Transmission
S. pullorum can be transmitted to chickens multiple ways.
- From laying hens to their offspring
- Direct or indirect contact with infected flock members (bird-to-bird contact, cannibalism or feather pecking of infected flock members, contaminated wounds, shed in feces that contaminates the environment, feeder, and waterer)
- Contamination of incubator or associated equipment
- Wild birds, rodents, wildlife, and insects (such as flies)
