Experimental in utero infection in fetal pigs with a porcine parvovirus.
The fetuses of six SPF sows at various stages of pregnancy were infected by direct inoculation into the amniotic sac. of 0.25 ml of tissue culture fluid containing 105.5 mean tissue culture infective doses per ml of porcine parvovirus strain G10/l. Fetuses of one uterus horn were infected, whereas fetuses in the opposite horn were given 0.25 ml of uninfected cell culture material. No clinical signs of infection were observed; however, all sows developed antibodies 7-9 days after infection. A total of 24 inoculated fetuses and 20 control fetuses were studied. Fetuses infected at 35, 48, and 55 days of gestation died about 5-22 days after infection. Virus was isolated from their organs and fetal blood. Virus spread to control fetuses, but did not cause death and mummification or stimulate antibody production. Fetuses from sows infected at 72, 99, and 105 days of gestation survived. They developed high antibody titres in utero. Control piglets remained antibody-free.