How are bison infected?
Epidemiological studies of field outbreaks strongly suggest that sheep infected with OvHV-2 are the principal source of MCF outbreaks in bison and cattle. A strong association between outbreaks in cattle and recent exposure to sheep has been documented repeatedly since 1929. Recent data indicate that a similar pattern occurs in bison. In some outbreaks, however, no sheep were in the vicinity immediately prior to the first case being identified.
