What to Expect When Your Mare Is Expecting

The months and weeks leading up to your mare’s due date can be exciting, but also stressful. The more prepared you are for what to expect, the less stressed you can be! This article will describe how to know your mare is close to foaling, what to have in your foaling kit ahead of time, and what to expect with a normal delivery.

Predicting Foaling

While the “standard” gestation length is 340 days, approximately 11 months, the actual gestation length of your mare can vary. Some mares will even foal out at close to 365 days gestation! Based on fetal development, we consider a foaling date of at least 320 days gestation to be “safe”.

How can you encourage your mare to foal as predictably as possible? Keep her environment safe, quiet, and predictable. Because of their nature as prey animals, horses will delay their foaling if they feel unsafe - this includes factors like new horses, moving barns/stalls, and turning the lights on at night to check on her frequently.

It is a good idea to start monitoring your mare daily 2-3 weeks prior to her due date. Each morning, you can examine the following parameters to predict when her foaling window is getting closer.

Udder: Palpate the mare’s udder to determine degree of edema and glandular development. Edema is fluid under the skin, and will typically “pit” when you push on it with your finger. Glandular development is more firm and uniform. Another benefit to this palpation is it gets a maiden mare used to touch in this area - she may be more receptive to the foal, and if there is a need to milk the mare after the foal is born, she’s already desensitized.
Teats: Less than a week before foaling, the teats will start to swell due to milk production. Approximately 48 hours prior to foaling, the teats will generally start to “wax”, secreting a substance similar to milk.
Pelvic ligaments: Palpate the ligaments to each side of the tail head. The area will loosen and become “jiggly” as foaling draws nearer.
Tail tone: As the pelvic ligaments relax, it will be much easier to manually lift the mare’s tail (gently).
Vulva: While you’re lifting the tail, visually inspect the vulva. It will gradually relax and elongate to prepare for foaling. Closer to the due date, you may notice a small amount of clear mucus. Any other drainage may be abnormal and warrants a call to the vet.
Milk pH: There are commercially available test strips that you can use to monitor the pH of your mare’s milk. This requires manually expressing some milk from her udder onto the pH strip. In theory, if the pH is below 6, the mare is more likely to foal imminently. This test requires a patient mare and some experience with milking. In some cases it is more accurate than others, but may be helpful.

Maiden Mares

Maiden mares (those who have not given birth before) often surprise us! Because their bodies are experiencing this for the first time, they may not show the signs we described above in a predictable way. It’s still a good idea to monitor these signs, but you should be watching for a foal past day 320 even in the absence of these signs. Maiden mares are extra sensitive to environmental changes and interruptions, so monitoring with foaling cameras is highly recommended.

Be Prepared

Foaling Stall

We recommend moving your mare to her new foaling stall (if her current stall is not appropriate) about one month prior to her due date, so she can be comfortable in her surroundings well in advance of foaling. The stall should be at least 14’ x 14’ with no small holes/openings large enough to fit a baby hoof through (or for a baby to escape through).

The stall should be well-ventilated and your mare should be able to visualize other horses; however, no other horses should be able to get too close to the mare/foal. Mares don’t even want their “best friends” sticking their noses into their foaling stall.

The bedding in a foaling stall should be straw (instead of shavings), as it is less dusty and doesn’t have as many small particles that can get in the foal’s nose and mouth. If you generally use shavings, you can make the switch as close to foaling as possible. A light layer of shavings is still recommended below the straw because it will help absorb and wick away fluids. Some owners will even wait until immediately after the foal is born to remove the wet shavings and add the straw - however this should only be done with experienced mares with a very low risk of being disturbed by the interruption.

Foaling Kit

We love large plastic bins as foaling kits! They are easily disinfected and carried, and they keep debris and dust from settling on the supplies. Keep your kit close to your foaling stall so that you don’t need to drag a big bin towards the stall while the mare is foaling. There are many commercially available foaling kits, and you can also put together your own. Here’s a list of the most important items to include, as compiled by our veterinarians with the help of our favorite resources.

Large, clean, absorbent towels (like bath towels)
Baling twine
Scissors
Box of clean latex gloves
Large plastic garbage bags (and/or empty grain bags)
Dilute chlorhexidine or betadine solution (1:4 with water) and small cups
Flashlight/headlamps
Numbers for your vet, friend/neighbor
Watch/clock
Clean buckets for warm water
Vet wrap
Foal enema
Ivory soap
Sterile lube
Foal bottle

Stages of Parturition

Finally - the big event! Unfortunately there are many abnormal occurrences that can happen with your mare’s foaling, or parturition, so it is important for you to understand what a “normal” parturition looks like, so that you know when to be concerned. Foaling occurs in the following three stages:

Stage 1: Preparation, Beginning of “Labor”

In the beginning stage of labor, your mare will look restless and uncomfortable. She may look colicky (sweating, getting up and down, rolling, loss of appetite, lifting tail, pacing). This is because the foal is repositioning into (hopefully!) the correct position for birth (both front feet at the cervix with the nose just behind). The mare’s uterus is also starting to contract. Different mares are in stage 1 for different periods of time - minutes to days. If they are interrupted, they can also pause stage 1 for a few days until they feel more comfortable. Depending on your mare’s temperament, you can wrap the mare’s tail with vet wrap to keep it out of the way during labor (if this is too disruptive, just wait until stage 2 for this step). It is best to mostly leave the mare alone during this stage, while maintaining a watch on her for the next step…

Stage 2: Birth!

Stage 1 ends and stage 2 begins when your mare’s “water breaks”, meaning there is a large release of fetal fluids. Make a note of exactly what time this happens, because the foal needs to be out of the mare within 30 minutes to avoid serious complications. Once her water breaks, she will often lay down and should be pushing vigorously. You should see the foal through a thin white membrane (called the amnion), which the foal typically breaks on its own during delivery. During this stage, call your vet if:

You can’t see any sign of a foal in 5-10 minutes
You don’t see all three expected body parts (foal nose + two front hooves)
You see a thick, red membrane coming out of the vulva. This is a “red bag” delivery, otherwise known as premature placental separation. The water often doesn’t even break because the placenta has prematurely separated from the uterus and is trying to be expelled from the body. This is a very serious emergency because the foal no longer has an oxygen source. Please start calling the vet at this point, but begin extracting the foal by opening the membranes with your scissors. Work quickly but carefully, as you do not want to cut too deep and injure the foal.

A normal stage 2 ends when the foal has been completely birthed from the mare. Again, make note of the time, because a lot of future milestones are based on time passed from birth. Give the mare and foal a few minutes to adjust and bond. The mare will likely start to lick the foal dry, and the foal may be trying to get up (this will likely not be very coordinated at all, don’t worry!) The foal should be picking his head up and breathing well. The one thing we recommend for you to do is to look at the umbilicus - it should have ripped on its own during birth or when the mare stood up. Allow it to rip on its own - this is healthier than cutting it. Dip the stump of the umbilicus in the dilute chlorhexidine or betadine solution. During this stage, call the vet if:

The foal is dull and doesn’t get more bright with vigorous towel-drying
There is a lot of bleeding from the umbilical stump
The mare seems extremely uncomfortable or there is a lot of active bleeding from her vulva
The foal is not able to stand within 1 hour

Once you have ensured the foal is making good progress, get out of the stall! We know it’s tempting to snuggle the new baby, but first you need to let the mare bond with the baby and do her job. Keep an eye on the pair as you watch for more milestones, especially nursing.

Stage 3: Passage of the Placenta

Stage 3 of parturition will likely be happening while you are focusing on the foal, but don’t forget to check on your mare! You will likely see the fetal membranes hanging from your mare’s vulva just after birth. This is because they’re still attached to the placenta and now she needs to “birth” the placenta as well! Use baling twine to tie up the fetal membranes (or knot them to themselves) so they aren’t dragging on the ground. You may notice in a few minutes they’re dragging on the ground again - that’s good because it means the placenta is making progress. Keep tying them up as it progresses. If the placenta has not passed in 3 hours from birth, call your vet.

Once the placenta passes, rinse it gently in water and collect the whole thing into a garbage bag or empty grain bag. The vet will want to examine it the day after foaling to make sure none of it has been left behind in the mare. Retained placental fragments can make the mare very sick, and they require immediate medical attention.

The amount of milestones to monitor for during birth can be overwhelming! Just remember that the most important ones follow the 1-2-3 rule! The foal should stand within an hour of birth and nurse within 2 hours of birth. The mare should pass the placenta within 3 hours of birth.

The Vet’s Role

We are happy to offer telemedicine consults as your mare foals if you are at all concerned. We may also ask you to send photos and videos to help us understand what is going on. Time is of the essence - if there are any problems with foaling, it is best to call the vet out to intervene sooner rather than later.

If everything goes smoothly, as described on this page, and you are feeling confident, call us first thing in the morning so we can celebrate with you! Even if you have no outward concerns, it is best to have the vet come out 12-24 hours after the foal’s birth. There are a few very important services we can provide.

Exam of Mare and Placenta

A lot has happened to your mare, and it’s important for us to make sure she has not sustained serious injuries and that she seems to be producing enough milk. We will also examine the placenta for damage and abnormalities, which may indicate we need to give the mare and/or foal some extra medical attention. We will also likely recommend deworming your mare with ivermectin at this time.

Exam of Foal

We will check for congenital defects or injuries sustained during birth and recommend any additional medical attention necessary. If the foal has not passed sufficient meconium (the hard, sticky, manure that accumulates in the foal’s intestines during fetal development), we can also help you administer the enema you have in your foal kit.

Foal Bloodwork

We will also take a blood sample to determine overall functioning of the foal and most importantly to run a stallside IgG test, which allows us to determine if the foal received enough good quality colostrum (the mare’s first milk) from the mare. IgG tests measure the antibodies that your foal has circulating in its bloodstream, which it received from its mare’s milk within the first 24 hours of its life. This is important because some foals don’t drink enough colostrum in the first 24 hours, and some mares don’t have good quality colostrum. These antibodies are the only things protecting the delicate foal from pathogens in the environment in its first few months of life. If the foal does not have an adequate IgG count, we will likely recommend intravenous plasma administration.