A mucosal disease virus infection of the pregnant ewe as a cause of a border disease-like condition.

An experiment was designed to investigate whether a condition in Australian sheep with clinical and pathological similarites to Border Disease was caused by the infection of the pregnant ewe with a Mucosal Disease virus (MDV). Forty ewes, at 58 to 63 days after mating, were inoculated with material from lambs in which all, some or none of the tissues examined contained MDV. The clinical condition was observed only in lambs born to ewes inoculated with MDV-positive material and then only to ewes in the group which had serological evidence of MDV infection. It is concluded that the Border Disease-like condition in Australian sheep is caused by the infection of the pregnant ewe with a Mucosal Disease virus.