Effects of experimental pseudorabies virus infection on vaccinated pregnant sows

In regard to field problems, a study was done to determine the effects of an infection with virulent Pseudorabies virus (PRV) on pregnant sows vaccinated with an inactivated virus vaccine. Three routes of viral inoculation have been tested: intranasal, intra-uterine and intra-fetal. The nasal infection did not allow to induce pregnancy disorders observed on the field on pregnant sows. After insemination with semen mixed with PRV, abortion was observed on one of the two immune sows. In this one, viral antigen has been identified on vagina, sacral and trigeminal ganglia. The second sow, slaughtered 2 months after infection presented a normal pregnancy. The results of intra-fetal inoculations showed that the vaccination does not prevent the spread of the virus from fetus to fetus and the pregnancy failure. These trials allowed to study the spread and repartition of the virus in the genital tract. PRV antibodies have been detected in the vaginal and uterine washing fluids as well as the follicular fluids of infected animals, vaccinated or not.