A case of bovine placental mole associated with twin embryonic death and resorption

Abstract

Extract

Bovine embryonic or foetal death with persistence of the foetal membranes has been reported to occur uncommonly (Folger, 1937; Kennedy and Miller, 1993). Following death and resorption of the embryo, the membranes may persist as an empty cystic structure, which corresponds in size to that of the foetal membranes of a viable pregnancy at 3–4 months gestation. Such a structure is known as a cystic placental mole. In such cases, both the allantois and amnion may be present. Folger (1937) was the first to describe this condition and an unusual cystic placental mole the size of a 3–4 month-old pregnancy, that contained only clear gelatinous fluid and accompanied by retention of the corpus luteum, has also been described by McEntee (1970). Such structures may become infected and form a pyometra, or may undergo necrosis and be expelled. This condition should not be confused with hydatidiform mole, which appears as a cluster of grape-like translucent cysts or villi of the placenta that are expelled during third-stage labour (Gylstorff, 1985). The latter is the more common occurrence in humans (Hewani et al, 1999; Salehnia et al, 2000). An abnormal embryonic development, characterised by formation of an embryonic vesicle without an embryo, has also been reported in a mare (Vanderwall et al, 2000).