Experimental inoculation of calves with laboratory strains of bovine viral diarrhea virus.

Diarrhea, erosions and ulcers of the oral mucosa, with conjunctival and nasal discharges, were observed in six calves inoculated with a mixture of two laboratory cytopathic reference strains of bovine viral diarrhea virus (BVDV)-Oregon C24 V and NADL. The clinical picture was accompanied by biphasic body temperature elevation, transient leukopenia and a decrease in the number of lymphocytes. High dose of viruses and multiple routes of inoculation promoted the development of clinical and hematological changes typical for BVDV infection although laboratory strains were used.