[Pathology and control of virus-induced enteritis in calves]

Considerable economic loss can arise from virus-caused enteritis in calves, in the form of so-called infectious factor diseases, which often develop more seriously when bacterial organisms, such as E. coli become involved. Rota-, corona- and parvoviruses are of particular interest. These pathogens have a marked predilection for intestinal epithelium. Rotavirus destroys the epithelial cells of the upper parts of the villi. Coronavirus penetrates to the base of the small intestinal villi and the superficial and crypt colonic epithelium is frequently affected. Infection of the small intestinal crypt epithelium is characteristic of parvovirus; loss of epithelium at the villus tip is also observed. Damage of the mucosa results in a reduction in digestive and absorbing capacity. It is not possible to treat these virus strains specifically. Great importance is therefore attached to the vaccination of dams as immune prophylaxis. Consumption of sufficient colostrum and milk from vaccinated dams affords the calves good protection. The mechanism is based on the presence of milk antibodies in the calf's intestine which neutralise orally ingested pathogens.