¿Cuánto dura el embarazo de una yegua?

La gestación equina dura unos 340 días de media, con variaciones normales entre 320 y 360 días. Es más larga que la de la mayoría de mamíferos domésticos. Los potros nacidos antes de los 320 días suelen considerarse prematuros y requieren atención veterinaria especial. El parto suele producirse de noche y de forma rápida (15-30 minutos en condiciones normales). La placenta debe expulsarse en menos de 3 horas tras el parto; si no, es urgencia veterinaria.

How long is a mare pregnant?

A mare's pregnancy lasts between 320 and 360 days, with an average of 340 days.

Detailed Explanation

Equine gestation averages around 340 days, with normal variations between 320 and 360 days. It is longer than that of most domestic mammals. Foals born before 320 days are usually considered premature and require special veterinary attention. Foaling usually occurs at night and is rapid (15-30 minutes under normal conditions). The placenta must be expelled within 3 hours after foaling; otherwise, it is a veterinary emergency.

Preparing for the foal's arrival

In addition to knowing the duration of gestation, it is advisable to prepare a calm, clean, and safe environment for the mare. Observe behavioral changes and consult the veterinarian if there are any abnormal signs.

It is also a good time to review basic stable equipment, hygiene, and protection for initial care.

The three stages of gestation

First trimester (months 1-4): the embryo implants and organs form. This is the phase with the highest risk of loss, so sudden changes in management and unnecessary long transports are avoided.
Second trimester (months 5-8): fetal growth is still moderate. The mare can maintain light work and her diet hardly needs adjustments.
Last trimester (months 9-11): the foal gains most of its weight. Here, nutritional needs increase, and it is advisable to reduce activity.

Signs that foaling is approaching

The udder fills in the last weeks and dry colostrum drops appear on the nipples.
The muscles next to the tail relax and the croup appears sunken.
The mare isolates herself, becomes restless, and may sweat.

Foaling in mares is rapid: once it starts, it is usually resolved in less than half an hour. That's why close monitoring is done in the days leading up to it, and the veterinarian should be notified if anything does not progress normally.

Care during gestation

Vaccination and deworming: following the veterinarian's schedule, which includes specific boosters during gestation.
Feeding: quality forage always available; extra feed is concentrated in the last months, not from the beginning.
Exercise: gentle and constant movement is beneficial. Both intense work and absolute box rest are detrimental.
Space: in the last weeks, a spacious and clean box with plenty of bedding is advisable.

Frequently Asked Questions

Can a pregnant mare be ridden?

During the first months, with light work and if the veterinarian does not indicate otherwise, yes. In the last trimester, ridden work is discontinued.

How often can a mare foal?

As gestation takes about eleven months, one foal per year is the maximum usual, and many breeders let the mare rest between foals.

How is gestation confirmed?

By ultrasound, which the veterinarian usually performs two weeks after breeding and repeats later to rule out embryonic loss and detect twins.

Related material in the store

For the management of the mare during and after gestation: