Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: June 25, 1996
Publication Date: N/A
Technical Abstract: In late 1995 and early 1996 the Wisconsin Animal Health Laboratory-Madison isolated bovine viral diarrhea virus (BVDV) from 6 Wisconsin dairy herds that reported high death loss (at least 20%) in adult animals. All 6 herds had purchased replacement animals shortly before the outbreak (1-3 weeks) and had a history of incomplete or no vaccination for BVDV. The clinical signs in the affected animals were high fevers (at least 105 deg F), depression, pneumonia, reduced milk production, and sudden death. Diarrhea was not a consistent clinical finding in the affected animals. One herd also had concurrent infection with bovine herpes virus 1. All six herds had a number of abortions (at least 20%) beginning approximately 2-3 weeks after the first recognized case of BVDV infection. All 6 isolates were sent to the National Animal Disease Center, Ames, Iowa, for genotyping and more in-depth analysis. The 5' untranslated region between bases 90 and 368 of the isolates were sequenced and all 6 isolates were confirmed to BVDV type 2. Sequencing was done from PCR amplicons by direct sequencing methods. Analysis of the aligned sequences indicated that the 6 isolates were about 99% similar suggesting a common point source herd. Two of the affected herds purchased animals from a dispersal sale at a commercial sale barn in early December 1995. The other 4 herd owners purchased animals from livestock dealers and did not know the source of the animals. This outbreak illustrates the importance of vaccination and biosecurity to prevent catastrophic losses due to BVDV infection.