Agerholm Jørgen Steen, Klas Eva-Maria, Damborg Peter, Borel Nicole, Pedersen Hanne Gervi, Christoffersen Mette
Department of Veterinary Clinical Sciences, University of Copenhagen, Høje Taastrup, Denmark.
Department of Molecular Biology, LABOKLIN GmbH & Co. KG, Bad Kissingen, Germany.
Front Vet Sci. 2021 Nov 10;8:740621. doi: 10.3389/fvets.2021.740621. eCollection 2021.
Loss of pregnancy in mares can have many different causes, including both infectious and non-infectious conditions. Extrapolation of findings from other studies is often uncertain as the significance of each cause varies across regions. Causes of pregnancy loss in mares have never been thoroughly studied in Denmark, so a prospective cross-sectional cohort study targeting the entire Danish population of pregnant mares was performed over a period of 13 months to obtain knowledge of the significance of individual causes. Fifty aborted or prematurely delivered stillborn fetuses were submitted for necropsy and examined by a panel of diagnostic laboratory methods. Overall, a cause of fetal loss was established for 72% of the examined cases. Most cases (62%) were lost due to a non-infectious cause, of which obstruction of the feto-placental blood circulation due to severe torsion of the umbilical cord was most prevalent. Pregnancy loss due to a variety of opportunistic bacteria, including bacteria not previously associated with abortion in mares, accounted for 12%, while equid alphaherpesvirus (EHV) type 1 was the cause of pregnancy loss in 8% of the cases. EHV type 4 and species were identified in some cases, but not regarded as the cause of fetal loss. Umbilical cord torsion was found to be the most prevalent cause of fetal loss in Danish mares, while infectious causes such as EHV type 1 and streptococci only accounted for a minor proportion of the losses. The study highlights the need for defined criteria for establishing an abortion diagnosis in mares, particularly in relation to EHV types 1 and 4.
母马妊娠丢失可能有许多不同原因，包括感染性和非感染性情况。由于各原因的重要性在不同地区有所不同，因此从其他研究推断结果往往不确定。丹麦从未对母马妊娠丢失的原因进行过全面研究，因此在13个月的时间里，针对丹麦所有怀孕母马进行了一项前瞻性横断面队列研究，以了解各个原因的重要性。五十具流产或早产的死胎被送去进行尸检，并通过一系列诊断实验室方法进行检查。总体而言，72%的检查病例确定了胎儿丢失的原因。大多数病例（62%）因非感染性原因丢失，其中脐带严重扭转导致胎儿 - 胎盘血液循环受阻最为常见。由多种机会性细菌引起的妊娠丢失，包括以前未与母马流产相关的细菌，占12%，而1型马疱疹病毒（EHV）是8%病例中妊娠丢失的原因。在一些病例中鉴定出了4型马疱疹病毒和其他种类，但不认为是胎儿丢失的原因。脐带扭转被发现是丹麦母马胎儿丢失的最常见原因，而诸如1型马疱疹病毒和链球菌等感染性原因仅占丢失病例的一小部分。该研究强调需要制定明确的标准来诊断母马流产，特别是与1型和4型马疱疹病毒相关的情况。
