Seventy cows in a 450-cow Holstein drylot dairy aborted from July 1990
through September 1992. Twenty of the 70 aborted fetuses were submitt
ed for laboratory examination. The 20 fetuses, including one mummified
fetus, had lesions suggestive of a protozoal etiology. Protozoa inclu
ding Neospora spp., Sarcocystis spp., and an unidentified protozoan we
re believed to be responsible for the abortions. Retrospectively, this
herd had experienced an epidemic of abortions and had a history of on
going abortions.