Update on retained fetal membranes

The equine placenta comprises the chorioallantois, the amnion and the placental vasculature. It can be defined as diffuse, microcotyledonary and epitheliochorionic in character. Release of the membranes commences following collapse of the fetal placental blood vessels, resulting in shrinking of the blood-deprived chorionic villi and relaxation of the maternal crypts [1]. This, in association with uterine contractions results in expulsion of the membranes. The fetal membranes are considered retained if they have not been expelled within 3 h [2]. The incidence of RFM in mares is 2–10% in normal foaling mares, with recognised risk factors and breed predilection as contributory factors [1]. Sequelae range from no clinical signs to death, potentially comprising metritis, laminitis, myocarditis and endotoxic shock, with prediction of outcome being impossible. As such treatment should always be aggressive ...