The replacement heifers were bred and housed separately for their first calving but at rebreeding they were mingled with other cows and their calves. An outbreak of Border Disease in a sheep flock. John Campbell et al. 1995. In March 1993, the owner of a farm in Southern Saskatchewan reports an abortion storm in his flock of sheep. Their fleece appears rough and lacks the smoothness of wool consisting primarily of long, dark grey to black hair.
Neurological signs are also apparent, manifested by rhythmic whole-body tremors.
The farmer started the flock three years ago with 60 cross-bred ewes. By spring 1993, he had expanded the flock to 140 breeding ewes by keeping replacement females from each lamb crop. Rams were introduced to the ewes in the first week of November 1992. The sheep were kept in a corral adjacent to two hundred heifers purchased a few months ago. The sheep had access to large alfalfa-rye hay bales and once a day, they were brought into a corral with a long central trough and fed rolled wheat.