Equine placenta – A clinician's perspective. Part 2: Abnormalities

Abstract

Summary Any insufficiency of the equine placenta has dramatic effects on the developing equine fetus. Placental abnormalities, such as the separation of the chorioallantois from the maternal endometrium or torsion of the umbilical cord, lead to fetal demise, premature labour or abortion. These conditions are each associated with characteristic lesions on the equine placenta, which can be found during a detailed examination. These findings can be very helpful for diagnosing problems and implementing appropriate treatments for mares and affected newborn foals. Furthermore, the retention of the entire placenta or any small fragment thereof can cause metritis, laminitis and sepsis. The prompt diagnosis and aggressive treatment of this condition is necessary to save the mare from becoming seriously ill. Therefore, a thorough evaluation of the equine placenta is a crucial element of the post partum evaluation of every brood mare.

Pregnancy loss due to amnionitis in anglo‐arabian mare—Case report

“…This is one of the few reports that describe in detail the microscopic findings of amnionitis in the equine species. Macroscopic analysis of the placenta showed characteristic presentation of amnionitis: the normally thin and transparent amnion was congested and thickened with prominent and congested vessels, corroborating the finding in a previous study with Pozor (). The appearance of ‘pearl necklace’ is consistent with the description in a previous report (Swerczek & Dorton, ).…”

Transcriptome Profiling of the Retained Fetal Membranes—An Insight in the Possible Pathogenesis of the Disease

“…Every case of RFM was diagnosed and treated by a veterinarian. Every placenta was examined visually by an experienced veterinarian for the placentitis and samples were taken only from normal placentas [ 14 , 15 ]. Horses were assigned retrospectively to two groups: Mares with RFM ( n = 3) and control mares ( n = 3) from which both tissues that are the endometrium and the allantochorion were sampled.…”

Die equine adenomatöse Allantoishyperplasie – ein Warnsignal?

“…[11][13] als typische Aborterreger bei Pferden [6] [24]. Doch auch ubiquitär auf tretende Umweltkeime konnten im Zusammenhang mit der EAAH nachgewiesen werden [17]. Interessanterweise wurde die EAAH bei Fohlenaborten durch das equine Herpesvirus, kongenitalen Miss bildungen, Dystokien, Nabelschnurtorsionen und Zwillingsträch tigkeiten bisher nicht beschrieben [11].…”

“…Eine weitere Differenzialdiagnose zur EAAH stellen entzündliche Veränderungen der equinen Plazenta dar. Die proliferativen Veränderungen in Verbindung mit Nocardien zeigen einen sehr ähnlichen Phänotyp mit adenomatöser Hyperplasie des Allantois epithels und einer Hyperplasie des Chorionepithels mit oder ohne squamöse Metaplasie [10] [17]. Allerdings zeichnet sich eine durch Nocardien induzierte Plazentitis durch eine hochgradige chronisch aktive eitrignekrotisierende Entzündung aus [10] [17], die bei der EAAH typischerweise nicht beobachtet wird [11].…”