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Equine Health Resource

Mare Should be Pregnant but Does Not Look It

Code Yellow - Contact Your Vet at Your Convenience for an Appointment

Code Yellow - Contact Your Vet at Your Convenience for an Appointment

  • Your vet can determine whether or not the mare is pregnant.

Mares that are pregnant have a roundness and a palpable springiness to their abdomen. The mammary glands should develop starting at 4-6 weeks before due date. However, mares that have had multiple foals may look pregnant even when they are not.

The equine pregnancy is 330-400+ days. The average gestation for light horses is about 335 days. Larger breeds tend to have longer pregnancies. Mares can be examined for pregnancy by your vet at as early as 14 days following the end of the heat cycle within which the mare was bred.


You wonder whether your mare is pregnant. She should be, but does not look or act pregnant. What should you do?

There is no way for you to definitively tell by visual assessment whether or not a mare is pregnant. While some mares become enormous in later pregnancy, others do not. In late term pregnancy, you may (or may not) notice the fetus moving in the mare’s flank. For this reason, you should contact your vet.


The first, early exam is done by ultrasound and rectal palpation. Vets typically perform a second exam at about 45-60 days. Rectal palpation for pregnancy can be done very early, but the added information provided with ultrasound is helpful.

In late term pregnancy, it is easy for your vet to determine whether or not the mare is pregnant using rectal palpation and ultrasound. Ultrasound through the abdominal wall can give more information about the health of the developing fetus. Hormone assays for pregnancy can confirm pregnancy only within specific time windows, but may be helpful in some situations.

Author: Doug Thal DVM Dipl. ABVP


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