Horse Labor and Birth Stages

When breeding horses, the general gestation period takes between 335 to 345 days. Professional breeders tend to move their pregnant mares into a breeding stable about two weeks before birth. The value of horses can be high. Breeders monitor mares closely for signs of labor and any problems with the birth.

  1. Impending Labor Signs

    • Close observation will indicate when the the mare is getting close to giving birth. A few days prior, the mare's udders will swell noticeably. When milk begins to drip from them, birth is usually less than 24 hours away. The area at the base of the tail will soften and become spongy, and the mare's vulva will widen noticeably. As the foal moves into position, the profile of the horse viewed from the rear changes from wide and shallow to more narrow and deep.

    Preparation Phase

    • The initial stage of the actual birth is known as the preparation phase. This stage can last for a few minutes or several hours; it is characterized by unsettled behavior. The mare may pace the stall, and alternate between laying down or standing up. As labor progresses, the mare begins nipping and nudging at its flanks. You may notice excessive tail raising and swishing. The mare often urinates and defecates frequently during this stage. The length of this phase is dependent on how relaxed the mare is; a nervous horse holds on longer.

    Birth Phase

    • The mare's water will break, which is distinct from normal urination by sheer volume. After the birth stage begins, the foal should be born within 20 to 60 minutes unless problems arise. Birth takes place with the mare laying on its side. The first visible sign of the birth is the appearance of the white membrane that makes up the amniotic sac. The foal's front feet should come out first, followed by the legs, nose, shoulders and the rest of the body. The foal's struggling should allow it to break the sac so it can get air.

    Placental Passage

    • When the foal is fully out, the final phase occurs. The mare rests for a few minutes. Assuming all is well and the foal is moving, avoid interfering in this stage in which the placenta is getting ready to naturally break. Either the foal's movement or the mother standing will cause the placenta to separate at the natural break point. The mare's uterus will continue contracting until the placenta is fully expelled, which should be within two hours.