Pathogenesis of Neonatal Calf Diarrhoea (NCD)

The pathogenesis and clinical presentation of diarrhoea in neonatal calves is variable. It is dependent on the causative pathogen/s involved.

Combined infections involving both a virus or viruses and Enterotoxigenic E coli (ETEC), result in a more severe and long-lasting disease than infections with a single pathogen. Combined infections can also lead to fatalities in older calves. Single-pathogen infections in older calves do not normally cause death.

Combined infections are common and typically about 20% of NCD cases involve more than one pathogen.

For more information on the specific pathogenesis of the different pathogens see the individual pathogens under causes of NCD.

Electronmicrograph of normal intestinal villi

Electronmicrograph of atrophied villi from the intestinal tract of a calf affected by neonatal diarrhoea.