Getting your mare checked for pregnancy: how and when?

First check: 14 to 16 days after covering

The earliest reliable ultrasound takes place around day 14 to 16 after ovulation. The vet uses rectal ultrasonography to visualise a vesicle of approximately 20 millimetres: the early embryonic vesicle. At this point it is also immediately possible to see whether a twin pregnancy is present, which can be dangerous in mares. Twins are almost always reduced as early as possible. Waiting longer makes that intervention more difficult. Schedule this appointment deliberately and add it to your EquiSight calendar so it does not get lost in the daily rush.

Second check around day 25 to 30

Around day 25 to 30, the vet checks whether the embryo is developing normally and whether a heartbeat is present. A heartbeat is a strong indicator that the pregnancy is viable. At this point the embryo already measures approximately 15 to 20 millimetres and is clearly distinguishable. Roughly 10 to 15 percent of pregnancies still end in early embryonic loss, so this check is far from unnecessary. Record the findings directly in your EquiSight horse profile so that your own vet and any other veterinarian always have access to the same information.

Further check-ups during pregnancy

After confirmation around day 30, a few more fixed check-up moments follow. The timing depends on your breeding goals, the age of the mare, and any risk factors.

• Day 45: check for normal development and any abnormalities
• Day 60 to 70: sex determination is sometimes already possible via ultrasound
• Month 5 to 6: blood test (eCG or PMSG) to confirm pregnancy
• Month 8 to 9: condition assessment and preparation of dietary adjustments
• 4 to 6 weeks before the expected foaling date: booster vaccinations and udder check

Ultrasound or blood test: which do you choose?

Ultrasound is the gold standard: fast, accurate, and applicable from an early stage. A blood test for eCG (equine chorionic gonadotropin) is reliable between day 40 and day 120, but provides no information about the condition or position of the embryo. After day 120, eCG disappears from the blood, after which a progesterone test can be performed. Many breeders combine both methods for extra certainty. Discuss with your vet which approach suits your mare's situation.

Signs to monitor at home

Between official check-ups you can keep a close eye on things yourself. Watch for the following changes:

• Teats becoming thicker and fuller (visible from month 8–9)
• Abdominal growth increasing, particularly on the right side
• Discharge from the vulva: clear mucus is normal, purulent discharge is not
• Behavioural changes such as becoming calmer or showing reduced appetite
• Udder beginning to fill in the last 2 to 4 weeks

Arrange nutrition and vaccinations in good time

From the seventh month the foal grows rapidly and the mare's nutritional requirements increase. Gradually raise energy and protein intake from that point — roughly 20 to 30 percent more than maintenance levels. Phosphorus, calcium, and vitamin E are especially important. Around 4 to 6 weeks before the expected foaling date, administer a booster vaccination against rhinopneumonitis and, if applicable, influenza. This ensures the foal receives antibodies directly through the colostrum. Use EquiCoach to align your vaccination schedule and feeding plan with the specific stage of the pregnancy.

Keeping a thorough pregnancy record pays off

A well-organised record prevents mistakes and helps you with a subsequent pregnancy or when selling the foal. Document every ultrasound, every blood result, and every notable moment. In the EquiSight horse profile you can save ultrasound images, add veterinary notes, and link calendar items to the pregnancy. That way you have a complete overview at any time — even when a stand-in vet or carer is involved.