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