Scanning Pregnant Mares

by / Friday, 06 September 2013 / Published in Horses, Large Animals, News Archive

Pregnancy testing the mare should be carried out on all pregnancies. We hear all too often of people waiting for 11 months only to find the mare was either never pregnant or has slipped the foal. Ultrasound has become the most common and reliable method for early pregnancy diagnosis in mares and is carried out generally from 16-25 days post breeding, this is also the time to check for twin pregnancies (which often result in the death of one or both foals, and sometimes the mare). Further pregnancy scans are often carried out after 45 days of pregnancy to confirm the presence of a heartbeat and again ideally at mid-pregnancy or if any abnormal udder development, discharge, or colic symptoms.

For ultrasound examination of the reproductive tract it is preferable that the mare be properly restrained in a crush. Most mares will tolerate the procedure very well and proper restraint is not only important for safety of the veterinarian performing the procedure, but will also ensure that no harm is made to the mare’s rectum.

mare-crush Ideally the tail should be wrapped to avoid inserting tail hairs into the rectum, the veterinarians arm is then fitted with a lubricated disposable plastic sleeve and is placed inside the rectum for careful removal of faeces, before scanning the uterus. If performed carefully, this is not a dangerous procedure and cautious palpation or ultrasound waves should not harm the early embryo or foetus.



The lubricated probe is then introduced into the rectum with the gloved arm to visualize the ovaries, uterus and the new developing embryo within. The veterinarian will follow every inch of the uterine horns and body to find the early embryo and to rule out the presence of twins for early twin reduction. Ultrasound during pregnancy also allows the veterinarian to monitor for normal growth and health of the embryo. Additionally if early embryo loss is detected owners can arrange to have the mare served again before the end of the breeding season.

Vet Cross has two mobile crushes enabling owners to have their mares tested at their own property rather than floating them to the clinic. 

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