English: 17.7. Tissues of PPV-infected fetuses of gilts experimentally infected oronasally. (A) Necrotic focus in liver of live fetus of a gilt infected on day 40 of gestation and killed 42 days later; fetus had numerous macroscopic lesions (H&E; ×400). (B) Perivascular cuffing with mononuclear cells in cerebrum of live fetus, littermate of A; fetus had no macroscopic lesions (H&E; ×320). (Insert) Viral antigen associated with endothelium of cerebral vessel of fetus of a gilt infected on day 46 of gestation and killed 25 days later (IF microscopy; ×312.5). All fetuses were probably infected by intrauterine spread of PPV from transplacentally infected littermates. (Photographs A and B courtesy of T. T. Brown, Jr., National Animal Disease Center.)