5 Experimental production of fatal mucosal disease in cattle.
Three outbreaks of mucosal disease were investigated. Careful examination of 47 cattle that were persistently viraemic with bovine virus diarrhea virus (BVDV)
Revealed no clinical disease,no or low levels of BVDV antibody and only non-cytopathic virus in their blood. The four animals with mucosal disease all showed clonical disease and both cytopathic and non-cytopathic virus in their blood.Following post mortem examination,there were particularly high levels of cytopathic virus in gut tissue. A hypothesis for the induction of mucosal disease is suggested. It states that animals become persistently infected with non-cytopathic virus following in utero infection and when,in post natal life, they become