Transmissible gastroenteritis of swine

TRANSMISSIBLE GASTROENTERITIS OF SWINE

  • First described in 1946. It is a highly contagious viral disease of young pigs. Clinically characterized by vomition, diarrhoea, dehydration and high mortality rate up to 100% in piglet under 2 weeks of age

Etiology

  • Corona virus – lacks haemagglutinating property and is antigenically related to feline infectious peritonitis and canine corona virus

Incidence

  • First described in 1946

Susceptibility

  • Young piglets

Transmission

  • Carrier pigs
  • Oral / Aerosol route
  • Virus excreted in milk / nasal secretions / faeces

Pathogenesis

  • Virusinfects the upper respiratory tract and intestine
  • Virus infects mature columnar epithelial cells of villibut not the undifferentiated cells in crypts
  • Replication occurs in 4 – 5 hours
  • With sloughing of infected cells and release of virus
  • After several replications there is marked reduction in villous size with villous atrophy in small intestine
  • Undifferentiated cells from crypts proliferate
  • Mainly jejunum is affected

Clinical signs

  • Piglets < 10 dats of age
    • Diarrhoea
    • Vomition
    • Excessive thirst
    • Weight loss
    • Dehydration
    • Death 2 – 5 days
  • Older piglets & adults
    • Profuse diarrhoea
    • Vomition
    • Failure to gain weight

Morbidity and Mortality

  • < 10 days old – 100% mortality
  • >10 days & adults – 100% morbidity, mortality is low

Gross lesions

  •  Carcass dehydrated
  •  Curdled milk in stomach
  •  Mucosa of stomach & small intestine congested

Microscopical lesions

  • Marked shortening and fusion of villi of small intestine

Diagnosis

  • Clinical signs
  • Histopathology of small intestine
  • ELISA, IFT, IPT, neutralization test – used for detection of virus in fresh tissues and feaces
Last modified: Monday, 19 March 2012, 8:38 AM