Extra-Amniotic Bovine Foetus With Aplasia of the Posterior Body: A Case Report.

To date, extra-amniotic foetal development has not been reported in cattle. In humans, such development outside the amniotic cavity is often associated with the formation of amniotic strands, which can lead to developmental malformations. Although congenital defects in the bovine species are uncommon, they typically result in significant economic losses due to production losses and additional veterinary costs. In this case, pregnancy was diagnosed in a primiparous Jersey-Holstein crossbred cow, 56 days after insemination, during routine pregnancy evaluation. Transrectal palpation revealed less uterine enlargement (i.e., corresponding to a 6-week pregnancy) than was expected for the gestational age. Ultrasound examination (using a Draminski, Poland) confirmed a right-horn pregnancy with an ipsilateral corpus luteum. Foetal length was measured at 41 mm, compared to the expected 50 mm at 56 days of gestation, according to the ultrasound software. The foetus exhibited severe malformations, including the complete absence of limbs and gross deformities caudal to the neck. Although the amnion was fluid-filled, the foetus was located outside of it, within the allantochorion. Abortion was induced, but the aborted material was not recovered. The cow successfully conceived again after one oestrous cycle and calved without complications. While most congenital defects are diagnosed postpartum, this case underscores the importance of performing routine ultrasound pregnancy diagnosis to enable the early detection of developmental abnormalities, facilitating timely intervention and reducing economic losses. To our knowledge, this is the first documented case of an extra-amniotic pregnancy in cattle.