After 11 months of pregnancy, the foal you’ve been waiting for has finally been born. You’re keeping a close eye on the foal, making sure it’s drinking on time and getting enough colostrum. But don’t forget to monitor your mare after delivery as well. It’s crucial to check that the placenta is expelled in its entirety and on time. If not it is called a retained placenta.

During pregnancy, the fetal membranes, also known as the placenta, provide the connection between the mare and her foal. The placenta serves as a conduit for nutrients that are necessary for proper foal development.

After the foal is born, the fetal membranes/placenta must be expelled; in layman’s terms, this is referred to as “passing the placenta.” It’s crucial to check if the placenta is fully expelled and if there are any abnormalities present. Normally, the placenta is passed within 1 hour after delivery. If the placenta has not been expelled after 3 hours, it is known as retained placenta (ret. sec.) and the mare is at risk. It’s important to contact your veterinarian immediately in such a situation! To find out what you need to monitor during delivery, download the free foaling checklist now!

Due to its multilayered structure, the horse placenta differs from that of humans and does not allow for the transfer of antibodies from the mare to the foal during pregnancy. As a result, the foal’s survival relies entirely on the intake of colostrum, or first milk, after birth. Interested in understanding whether your foal has received sufficient colostrum? Check out my blog post titled: Did my newborn foal drink enough colostrum?

Causes of a retained placenta
In 10% of mares, the placenta remains retained for too long, but cold-blooded and Friesian horses are particularly susceptible. A mare that has previously retained the placenta is three times more likely to do so again in a subsequent pregnancy. The environment, nutrition, genetic factors, and the progress of the delivery also play an important role. It is more common to see a mare retain the placenta when there is a difficult delivery.


When the placenta remains retained after delivery, it poses a great risk to the mare. The placenta is a vital connection between the mare and the foal, but once the foal is born, the placenta becomes dead tissue, which can lead to uterine infections, laminitis, and sepsis, which can cause the mare to become seriously ill and sometimes even die.

Treatment of a retained placenta in your mare

If the placenta remains retained for too long, a veterinarian must intervene. The treatment of the mare consists of various components. Depending on the timing and amount of placenta that remains, various therapies can be implemented.

The first step involves administering the hormone oxytocin, which causes contractions of the uterine wall, causing the placenta to come loose. This hormone can be administered as an injection or through a drip.

The second step is to remove the placenta. Preferably, the veterinarian tries to detach the placenta first by administering a hormone (step 1), as this causes the least trauma, but it is often necessary to remove the retained fetal membranes. There are different methods for doing this, and your veterinarian will choose the method that is best for your mare at that time:

  • Gently peeling off the placenta by the veterinarian
  • Garden hose method by the veterinarian

Depending on how long the mare retained the placenta and how it was removed, the veterinarian will flush the uterus. The uterus is flushed to wash out bacteria and debris. Sometimes it is necessary to do this several times a day, for several days in a row. If necessary, your veterinarian may also prescribe anti-inflammatory drugs and/or antibiotics.

Check your mare at least twice daily

After the foal is born, it is important to monitor the mare closely and measure her temperature twice a day to watch for signs of uterine infection. Contact your veterinarian immediately if your mare’s temperature is elevated (higher than 38.3 degrees Celsius), she refuses to eat, or begins to walk stiffly. Stiff walking may indicate an early stage of laminitis, as toxins are released during uterine infection.

The arrival of a foal is certainly an exhilarating experience, but it is important to note that the foaling process is not yet complete. Adequate postnatal care for both the mare and foal is of utmost importance. To prevent complications and unnecessary suffering for the mare, it is essential to intervene as soon as possible if things go wrong. So keep a close eye on your mare and call your equine veterinarian right away if necessary.

Blog in collaboration with Kim ter Bruggen

Do you want to know when to call the veterinarian and learn how to check if the placenta has been fully expelled? I will tell you all you need to know about it in my online foaling course!

In my work as an equine veterinarian, I receive many questions from owners regarding foals. Not only the birth, but also questions about a sick foal or deworming and vaccination of foals.

In my online foaling course, I answer many questions about the birth and first week of your foal’s life! In my online course, you will learn what you can do best before, during, and after birth. Almost 500 participants have already enrolled and rate the course with 5 stars! Experienced breeders also say they have learned a lot from the course!