Abortion and fetal death in sows

Abstract

Abortion in sows or the expulsion of foetuses between days 35 and 109 of gestation results in major financial losses. Abortion is the result of maternal failure due to factors interfering with either the endocrine control of pregnancy or causing endometrial damage. In addition, causes of fetal origin, due to infections with a special affinity for the fetus, can also lead to abortion. Many different non‐infectious and infectious factors may be involved. Non‐infectious risk factors include inappropriate ambient temperature, seasonal effects, different stress factors, and toxic substances. Microorganisms that may cause abortion can be classified as facultative pathogenic and specific pathogenic microorganisms. The first category includes mostly bacteria that are endemic in many pig farms and that are normally harmless commensals. They can cause abortion only in case of decreased immunity or other predisposing factors. Different specific pathogenic microorganisms, especially viruses and bacteria, can cause fetal death and abortion. Some may have a special affinity for the reproductive tract and the foetuses (e.g. Aujeszky's disease virus, parvovirus, Leptospira sp.), while others may cause clinical disease or fever in sows (e.g. swine influenza viruses, Erysipelothrix rhusiopathiae), subsequently leading to abortion. Diagnosis of fetal death and abortion is challenging due to the broad array of processes that may be involved, and the fact that the inciting cause may happen well in advance of the abortion. The diagnostic process should start with a thorough evaluation of the clinical problem and the farm. In case an infectious cause is suspected, proper samples should be collected, preferably from different sows and foetuses, for the detection of specific pathogens. Prevention of abortion mainly relies on the implementation of good management practices, hygiene and biosecurity measures, and for some pathogens also on vaccination.

Characterization of Removal Reasons for Nurse Sows and the Associated Removal Due to Their Extended Lactation Length in Hyperprolific Farrow-Wean Herds

“…In this study, removal through abortion was not significant ( p > 0.001) among all parities, similar to the findings of Tummaruk et al [ 46 ] when analyzing 30,058 removed sow records. Abortion may happen at any parity, although summertime heat stress has been linked to greater risks of abortion [ 47 , 48 ]. However, seasonality was not considered in this study.…”

Causes of pregnancy arrest in the canine species

“…This article aims to review the causes of pregnancy termination in the bitch, which are found in the literature, both at the embryonic and foetal stages. This paper in one of a series of papers on abortion in animals commissioned by Reproduction in Domestic Animals and includes others on abortion in cattle (Mee, 2023), in horses (Leon et al, 2023) and in pigs (Maes et al, 2023).…”

Overview of the causes of abortion in horses, their follow‐up and management

“…In all these studies, the origin of the abortion was classified into primary non-infectious, infectious and unknown causes (Table 1) and secondary diagnostic categories (Table 2). The involvement of pathogens in abortion in horses was also investigated by comparison with published data in humans, including zoonotic pathogens or other species such as cattle (Mee, 2023), pigs (Maes et al, 2023) and dogs (Fontbonne, 2023).…”

“…This review will present the known causes of abortion in horses, their follow-up and the management of the most important infectious diseases. This paper is one of a series on abortion in animals commissioned by Reproduction in Domestic Animals (Fontbonne, 2023;Maes et al, 2023;Mee, 2023).…”