Cache Valley Virus (CVV) is a causative agent of a mosquitoborne disea
se syndrome of sheep and, possibly, of all ruminants, characterized by
embryonic and fetal death, stillbirths, and multiple congential malfo
rmations. CVV is endemic in Canada, Mexico, and the United States. Sev
eral related Bunyviruses also may play a role in syndromes of congenti
al malformations and embryonic losses in North America.