Diseases: Salmonella Infections
Introduction
A range of acute and chronic diseases caused by bacteria
- Pullorum disease, an acute disease of chicks caused by Salmonella pullorum
- Fowl typhoid, an acute and chronic disease mostly of adult chickens caused by Salmonella gallinarum.
Clinical Signs
Pullorum disease in young chicks
- weakness
- loss of appetite,
- droopy wings
- soiling of vent
Fowl typhoid in older birds
- ruffled feathers
- pale, shrunken combs
Post Mortem Lesions
Acute disease
- enlarged, dark liver, spleen and kidneys
- may be white spots in liver
- may be white nodules in lungs may be swollen joints
Chronic disease in adult birds
- misshapen, discoloured cystic ova
- peritonitis
- perihepatitis
- pericarditis
Diagnosis
- Confirmed by demonstration of organism, or specific antibodies in serum.
Samples
- For culture of organism, swabs or samples of most body tissues but liver, spleen and caeca are preferred.
- Serum for chronic infections.
Transmission
- May be transmitted through the egg (vertical transmission)
- Spread by contact with infected birds, through wounds on skin
- In feed, water and litter contaminated with faeces from infected birds
- On contaminated persons, shoes etc.
Treatment
- Sulphonamide drugs such as sulfadiazine, sulfamerazine, and sulfathiazole via feed or water will reduce mortality. N.B. The withdrawal period is a minimum of 10 days before slaughter for food.
Prevention and Control
- Good flock management – do not introduce sick or new birds
- Vaccines against Fowl Typhoid are available in some countries
- Organism is relatively resistant to environmental conditions
- Organism is inactivated quickly on exposure to sunlight
