Experimental Infection of 35, 50 and 60 Day Old Pig Foetuses With Porcine Parvovirus

Abstract

Foetuses of six seronegative gilts, two of which each respectively 35, 50 and 60 days pregnant, were inoculated intrauterinely with porcine parvovirus (PPV) and examined 7 and 11 days after inoculation. HI antibody was not detected in any of the foetuses although all but one gilt developed low levels of antibody. All but one of the foetuses inoculated with PPV died in utero prior to examination at 11 days after inoculation. Infection also spread to non-inoculated litter mates. Histological changes were mild in the gilts but there was widespread tissue necrosis in infected foetuses, and intranuclear inclusion bodies were observed in cells of the liver, lung, kidney and cerebellum. The increased survival of foetuses infected at later stages of gestation appeared to be related to increased numbers of mononuclear cells then present in many tissues.

Porcine Abortions Associated with Fungi, Actinomycetes, and Rhodococcus sp

“…Although parvovirus was isolated from the pigs aborted by Sow III, the lesions and history indicate that placentitis caused by A. fumigatus was the immediate cause of the abortion. We found no lesions consistent with prenatal parvovirus infection, and pig fetuses of more than 70 days gestation usually are resistant to effects ofparvovirus infection [5].…”

Increasing diversity of swine parvoviruses and their epidemiology in African pigs

“…At a gestation period of 35 days and above when bone formation begins, the viral infection gives rise to foetal death and mummification. Finally, if a pregnant sow is infected at the advanced stage of gestation of 70 days and above, its foetus has already become immuno-competent at that point; hence, the foetus can independently resist the viral infection and becomes seropositive at birth with likelihood of having a subclinical infection status (Lenghaus et al, 1978;Mengeling et al, 2000;Zeeuw et al, 2007).…”

Animal Parvoviruses: Comparative Aspects and Diagnosis

“…Dead fetuses were found in one-third of the litters (203), of which 75% contained PPV. This seems to be directly related to the increased number of mononuclear cells then present in many tissues (Lenghaus et al, 1978). Virtually all contained the viral antigen, whereas only half of the live litters possessed this antigen.…”

“…Mengeling (1978) examined slaugh tered sows, which had been gravid for over 60 days, for dead fetuses and embryos. Intrauterine inoculations at later stages of gestation appear to increase the chance of survival of the fetuses (Lenghaus et al, 1978). The fetuses of the PPV-infected litters were mostly mummified (84%).…”