Ultrasound and endocrine findings that help to assess the risk of late embryo/early foetal loss by non-infectious cause in dairy cattle.

This report reviews the clinical applications of routine ultrasound in gestation control programmes for dairy herds. Emphasis is placed on identifying risks of late embryo/early foetal loss of non-infectious cause by monitoring ovarian structures (as opposed to uterine contents), indicators of pregnancy loss and twin pregnancies. Suggestions are provided to appropriately manage a cow at risk of pregnancy loss during the late embryonic/early foetal period. This review identifies gaps in our current knowledge of the aetiology of pregnancy loss and spontaneous embryo/corpus luteum reduction. Two areas of the implantation-placentation window of gestation in particular need urgent attention: the roles in pregnancy loss of immune-endocrine interactions and the physiological status of the embryo/corpus luteum. The latter issue and consecutively endocrine interactions could be successfully addressed by incorporating Doppler ultrasonography into routine ultrasound procedures.