Signs of Pregnancy in Horses

While there are very few sure methods of determining if a horse is pregnant, armed with a little information, you could prepare yourself for the new arrival more than just the day before.

  1. Early Pregnancy

    • Mares in their early pregnancy can be nearly impossible to determine because of few physical signs. But they will share some symptoms such as ignoring stallions or not entering heat for four weeks or more. There are chemical and nonchemical tests available, but they must be applied at the proper time, and carefully, or the results might be misleading.

    Midterm

    • Mares at midterm will start to show physical symptoms such as losing the "flank" (the hollow separating the barrel from the hip where the hairs grow away from each other) and gaining weight along the underbelly.

    Late Pregnancy

    • In late pregnancy, it should be obvious the mare is pregnant by her heavy belly, slow, cautious movements, and changes in temperament.

    Preparing for Birth

    • The last few weeks, days and hours before birth, there are multiple signs to alert the owner the foal is ready to arrive. The udder will fill two to four weeks before foaling, and the teats will distend. One to four days before foaling, the teats will gather little drops of wax (the colostrum) and some mares might drip milk.

    Key Times

    • The early days of pregnancy are key as factors such as stress, hormonal abnormalities, twin embryos or infection can cause reabsorption of the embryo. Preparing for birth is also a key time to watch your mare. Try to keep her stress levels low and ensure as much comfort as possible.