Neonatal calf diarrhoea

NEONATAL CALF DIARRHOEA

Synonym - Scours

Definition

  • It is an acute disease affecting young calves charecterised by severe diarrhoea and very high mortality caused by rota virus

Susceptibility

  • 2 weeks old calves

Clinical Signs

  • Yellowish, watery diarrhoea, dehydration

Morbidity and Mortality

  • High

Transmission

  • Virus shed in facces
  • Direct contact
  • Contamination of water supplies
  • Airborne

Pathogenesis

  • Entry of virus by ingestion
  • Infects epithelial cells of small intestine
  • Only differentiated columnar epithelial cells lining the apical halves of villi are susceptible -mature enterocytes are affected
  • Group A rota viruses causes necrosis, sloughing, stunted villi, hypertrophy of enterocytes in crypts- mature enterocytes are affected
  • Group B rota viruses are associated with multinucleated cells / syncytia on surface of villi

Gross lesions

  • Congestion and haemorrhage in the small intestine

Microscopical lesions

  • Group A rotavirus
    • Necrosis, sloughing and stunting of villi
    • Hypertrophy of enterocytes of crypts
  • Group B rotavirus
    • Multinucleated cells, Syncytia formation (fusion of enterocytes) on surface of villi

Diagnosis

  • Detection of rotavirus in faeces, intestinal contents and tissues
  • Immunofluorescent staining of faeces up to 4-6 hours
  • Electron microscopy of faecal material up to 6-10 days after onset of diarrhoea
  • ELISA – sensitive
Last modified: Monday, 19 March 2012, 8:33 AM