How to Scan a Mare for Pregnancy Diagnosis

Introduction
Early and accurate pregnancy diagnosis is an important for efficient stud management for 3 key reasons.

• The high value of early-born foals requires that empty mares are rapidly rebred.

• Nonviable pregnancies must be detected and aborted before Day 35 when hCG secretion from the endometrialcups will prevent rebreeding.
• Manual reduction of multiple pregnancies is most successful before embryo fixation occurs around Day 16 post conception.

Ultrasound in pregnancy diagnosis
Currently, these requirements can only be met by trans-rectal ultrasound imaging. Although pregnancy can be detected by trans-rectal palpation from Day 30–40 post conception, this incurs significant delays in rebreeding empty mares and can neither reliably identify twins nor appraise embryo quality. Ultrasound imaging transformed stud medicine, almost halving abortion rates alone through the identification and reduction of multiple pregnancies (McKinnon 2010). [...]