In this case report, the course of a bovine viral diarrhea virus infection (BVDV) type 2 in a Belgiandairy herd is described. Within a period of fourteen days, seventeen adult dairy cows died of acute diarrheaand dehydration. A BVDV infection was suspected from the beginning but this suspicion couldnot be confirmed by testing. Only during the next thirty-four months at different time points, BVDVtype 2a could be identified.