Abortion in sows experimentally infected with African swine fever virus: clinical features.

Thirteen sows between 38 and 92 days of pregnancy were exposed oronasally to African swine fever virus (1979 Dominican Republic isolate) to determine whether infection would affect their reproductive performance. Abortions occurred in sows in all stages of pregnancy. Of 11 sows, 7 aborted 5 to 8 (6.1 +/- 0.90) days after inoculation or 0 to 3 (1.4 +/- 0.98) days after fever development. Abortions occurred soon after clinical signs of infection first developed and viremia titers peaked. Swelling of the vulva and treading preceded abortion in some sows. Ecchymotic placental and petechial cutaneous hemorrhages were present in 6 of 13 and 9 of 13 litters, respectively. African swine fever was transmitted to 2 healthy barrows by feeding fetal tissues collected from 1 inoculated sow. All inoculated sows not killed, died, precluding further study of neonates from infected sows.