Viral agents and associated lesions detected in a 10-year study of bovine abortions and stillbirths.

In a 10-year survey started in 1980, specimens from 8,995 bovine abortions and stillbirths were submitted to the South Dakota Animal Disease Research and Diagnostic Laboratory. Of these, 8,962 were suitable for some type of examination. Viruses were associated with 948 (10.58%). Bovine herpesvirus-1 (IBR) was detected in 485 (5.41%), and bovine viral diarrhea virus (BVDV) was detected in 407 (4.54%). In 1 year of the survey, BVDV was detected in 8/32 fetuses that had lesions of passive congestion. Bovine herpesvirus-4 was isolated from 47 specimens (0.52%), parvovirus and enterovirus were each isolated from 2, and adenovirus, parainfluenza virus, and pseudorabies virus were each isolated from 1. Malignant lymphoid neoplasia was present in 2 fetuses, and their abortion was assumed to have been caused by the bovine leukosis virus.