Fowl Typhoid (Salmonella gallinarum) Pathology & Control
Veterinary manual covering Salmonella gallinarum septicemia, bronze metallic liver, green-yellow diarrhea, 9R vaccine, and PT testing.
Scientific Overview
Fowl Typhoid is a severe septicaemic bacterial disease of poultry caused by Salmonella enterica serovar Gallinarum. Affecting both young chicks and adult chickens, Fowl Typhoid causes high mortality, bronze metallic liver discoloration, and greenish diarrhea, posing a significant risk to commercial egg layer and breeder farms.
Etiology & Salmonella gallinarum Characteristics
Salmonella gallinarum is defined as a non-motile, host-adapted Gram-negative enterobacterium specific to avian species.
Transmission occurs via vertical transmission in eggs or horizontal transmission through ingestion of feed, water, or litter contaminated by infected bird droppings.
Pathognomonic Lesions: Bronze Liver & Green Diarrhea
Necropsy lesions include:
- Bronze Metallic Liver: Enlarged liver exhibiting a characteristic greenish-bronze metallic sheen upon exposure to air.
- Greenish-Yellow Diarrhea: Severe enteritis leading to profuse watery yellow-green droppings and vent staining.
- Splenomegaly & Fibrous Peritonitis: Spleen and kidneys are dark and enlarged, with pinpoint necrotic foci.
Control: Live 9R Vaccine & Pullorum-Typhoid Testing
Control relies on maintaining Pullorum-Typhoid Clean breeder status through whole-blood plate agglutination testing. In endemic areas, commercial layer pullets are immunized using the live rough 9R Salmonella gallinarum strain vaccine between 6 and 8 weeks of age.
All scientific data, diagnostic criteria, and performance benchmarks presented on this page are derived from published peer-reviewed journals and official veterinary codes:
- Avian Pathology & Diagnostics: World Organisation for Animal Health (WOAH, 2023). Manual of Diagnostic Tests and Vaccines for Terrestrial Animals. Paris, France.
- Poultry Diseases & Histology: Swayne, D.E., et al. (2020). Diseases of Poultry (14th ed.). Wiley-Blackwell / American Association of Avian Pathologists.
- Nutrition & Feed Chemistry: Leeson, S. & Summers, J.D. (2001). Commercial Poultry Nutrition (3rd ed.). University Books, Guelph, Ontario.
- Commercial Breed Standards: Aviagen (2024). Ross 308 & Cobb 500 Broiler Performance Objectives. / Lohmann Breeders (2024). Lohmann Brown Management Guide.