Causative agent
- Streptococcus suis (Group D)
- Streptococcus equisimilis (Group C and Group L)


Differential diagnosis
- Swine fever
- Pseudorabies
- Swine erysipelas
- Hemophilus parasuis infection
- Swine pleuropneumonia
- Toxoplasmosis


1. History taking
- Prevalent in piglets especially newborns and
  weaners
- Carrier pig harbors the organism in its tonsil
- Predisposed by various stresses


2. Clinical examination
- Sudden death in peracute cases
- High fever, anorexia, depression involvement
- Central nervous symptoms : incoordination,
  paralysis, paddling movements, opisthotonus,
  tremors and convulsion
- Blindness, deafness and lameness
- Arthritis in chronic cases


3. Necropsy
- Meningitis : edema and congestion of the brain
  and meninges, excess and turbid cerebrospinal
  fluid
- Septicemia : reddening of the carcass,
  enlargement of lymph nodes and parenchymatous
  organs
- Polyarthritis : supurative polyartritis, joint capsule
  may be thickening


4. Histopathological observation
- Typical changes of acute bacterial menigitis,
  congestion of the cerebral blood vessels, purulent
  material in the subarachnoid space

- In affected lung: various degrees of consolidation
  and fibrinopurulent bronchopneumonia


5. Microscopic examination
- Pus smear and staining : Gram positive cocci (short
  chain) or coccobacilli


6. Bacterial isolation
Specimen : visceral organs, blood (septicemic type)
                  exudate or joint fluid
Medium    : blood agar and blood agar with polymyxin
                  B, incubate 30°C for 24-48 hr aerobically or
                  under 5-10% CO₂
- Identification : small, smooth or mucoid colony α, β or
  no hemolysis (commercial kits are available for
  identification and serotyping)


7. Serotyping