Causative agent
- Salmonella gallinarum (Fowl typhoid, FT)
- Salmonella pullorum (Pullorum disease, PD)
- Salmonella typhimurium, S. enteritidis and others
  (Paratyphoid, PT)


Differential diagnosis
- Avian colibacillosis
- Newcastle disease
- Infectious bursal disease
- Fowl plaque (Avian influenza)
- Fowl cholera
- Avian fungal pneumonia
- Avian staphylococcosis


1. History taking
- Transmitted in egg in PD
- Mostly transmitted from outside of the shells (on
  egg) in PT
- Spread horizontally in hatchery, breeder and the
  contaminated materials
- High mortality due to septicemia within few days
  after hatching in PD, and 5-10% die within 2 weeks
  of age in PT
- Decreased egg production and hatchability
- Increase embryonic death and dead in shell


2. Clinical examination
- Acute : white diarrhea, septicemia, high mortality
  in baby chicken (PD, PT) and poults (FT, PT)
- Chronic : ovarian infection in mature hens in PD
  and PT due to S. enteritidis infection
- Mostly no clinical signs in adult chicken except
  drop in egg production
- Respiratory signs, arthritis and blindness (PT, PD)


3. Necropsy
- Enlarged liver with pale color
- Necrotic foci or nodules in liver, lung, intestine,
  cardiac muscle and gizzard muscle

- Thickening of cecal wall with a cheese curd-like
  core
- Regression of ovary and salpingitis


4. Histopathological observation
- Focal degeneration and necrosis of liver
- Focal necrosis of myocardium, catarrhal enteritis
  and catarrhal bronchitis
- Serositis and serosa consisted of infiltrating
  lymphocytes, plasma cells and heterophils and
  proliferation of fibrocytes, fibroblastic cells and
  histiocytes
- No lesions in chicks under 10 days of age


5. Serological test
- Plate agglutination test using whole blood (PD)
- Tube agglutination test


6. Bacterial isolation
Specimen : liver, spleen, heart, unabsorbed yolk
sacs or any other tissues (ovary in
adults)
- Propagational culture : Tetrathionate broth or
  selenite broth
- Selective medium : Modified semi-solid
  Rappaport Vassiliadis (MSRV), Brilliant green
  agar, xylose lysine desoxycholate and others
- Identification : by biochemical characters


7. Serotyping
- O antigen, H antigen : slide agglutination test


Control
- Hatchery sanitation
- Fumigation of incubators before use
- Separation of eggs or chicks from different flocks
- Separation of birds of different ages
- Separation of birds of different species
- Selection of clean feed stuff
- Eradication of all pets and rodent