In this case report, the course of a bovine viral diarrhea infection (BVD) type 2 in a Belgian dairy herd is described. Within a period of fourteen days, seventeen adult dairy cows died of acute diarrhea and dehydration. A BVDV infection was suspected from the beginning but this suspicion could not be confirmed by testing. Only during the next thirty-four months at different time points, BVDV type 2a could be identified.