11 Signs of Foaling in Horses – [Preparation for Labour] | Mad Barn (2024)

Breeding a mare involves a significant investment of time and resources, but the potential rewards are profound. From seeing your newborn foal take its first steps to celebrating their triumphs in equestrian sports, the experience is unforgettable.

Mares have a long gestation period, with the average pregnancy lasting between 335 to 350 days, or roughly 11 months. However, gestations can last anywhere between 320 to 360 days. ^[1][2]

As your mare approaches the end of her gestation period, it’s important to be vigilant for changes that indicate foaling is near. Recognizing these signs ensures you can make necessary arrangements and provide appropriate care during the birthing process.

Fortunately, 90% of foalings do not require human intervention. But if complications arise, timely intervention is crucial to safeguard the well-being of both the mare and her foal. ^[1]

In this article, we will discuss the 11 key signs that your mare is ready to foal. We will also discuss essential preparations for your mare’s foaling, including what you need in your foaling kit and how to identify the various stages of labor.

Foaling in Mares

Being well-prepared for foaling can help ensure the health and safety of both your mare and her foal. Although less than 10% of pregnancies involve dystocia (difficulty giving birth), when problems occur prompt intervention is essential. ^[1]

Many different factors can influence gestation length, including the mare’s age, previous pregnancies, fetal sex, genetics, and season. ^[1][3][4] Because of this, accurately predicting the exact foaling date for your mare can be challenging.

Regular veterinary check-ups can help monitor the mare’s progress and provide a more accurate foaling window, but there is no foolproof method to predict in advance when your mare will go into labor.

Instead, the best way to anticipate the onset of labor is to watch for behavioral and physical changes in your mare as she nears her due date. Telltale signs that your mare is close to foaling include changes in udder shape and body temperature, as well as waxing at the teats.

Keep in mind that most mares foal during the night, corresponding to times with minimal commotion. ^[5] This underscores the need for owners to recognize signs that a mare is close to foaling, ensuring assistance is on hand during the birthing process.

Foaling Calculator

A foaling calculator can help you estimate when your mare will give birth based on her last breeding date. While a calculator cannot guarantee an exact date due to variability in gestation length, it can offer a guideline to help you prepare.

Input your mare’s last breeding date below to receive a predicted foaling window based on average gestation lengths.

Foals born prior to 320 days of gestation are considered premature and may require more intensive veterinary care.

11 Signs of Foaling in Mares

In the following section, we will describe the common physical changes a mare may experience as she approaches foaling. Remember that each mare is unique; while some exhibit these changes weeks in advance, others may show them just days prior to foaling.

Maiden mares experiencing their first pregnancy, may not follow a typical timeline. ^[11] They warrant special attention throughout the gestation period to ensure a healthy delivery.

1) Mammary Gland Development

When a foal is first born, they are entirely reliant on colostrum and milk from their dam to provide all of their nutrition. During pregnancy, the mare’s mammary glands go through several changes to prepare the mare for lactation post-foaling.

As early as 4 to 6 weeks prior to parturition, you may notice your mare’s udder hardening and appearing fuller. Enlargement of the udder is most noticeable in the last two weeks before giving birth. ^[2]

This fullness is a result of mammary tissues in the udder beginning to produce milk. As the expected foaling date approaches, the two halves of the udders will further fill with milk and feel firmer to the touch.

The udders may look more square or boxy, with the crease between the two halves becoming less pronounced. You may notice some edema or swelling forming around the udders, which may have a clay-like texture.

Figure 1: This image shows the weekly progression of the mammary gland as foaling approaches.

Figure 2: This image depicts edema or swelling that can form around the mammary gland.

2) Behavioural Changes

As foaling approaches, your mare may exhibit a variety of behavioural changes. Knowing your mare’s personality and recognizing changes in her behaviour can help you anticipate foaling and provide the necessary support. ^[10]

Here are some common behavioural changes observed in mares as they near parturition: ^[17][21]

Restlessness: One of the first signs that foaling might be near is an increase in restlessness. Your mare might walk around more, appear agitated, or frequently change positions.

Tail Raising: As contractions begin and intensify, your mare might frequently raise her tail. This is a response to the discomfort she feels as the foal starts to move into position.

Loss of Appetite: As foaling nears, your mare might lose interest in food, even if she’s typically a good eater.

Frequent Urination: Mares often urinate more frequently in the hours leading up to birth. This is partly due to the pressure exerted by the foal on the mare’s bladder.

Looking at Flanks: The mare may repeatedly turn her head to look at her flanks or belly. This behaviour is believed to be a response to the movements of the foal and the sensations of early contractions.

Isolation: In a herd setting, a mare close to foaling might distance herself from the rest of the group to find a secluded spot to give birth.

Nesting Behaviour: Some mares display nesting behaviour, where they might dig at the ground with their front hooves, creating a depression or “nest” in which to foal.

Sweating: It’s not uncommon for mares to break into a sweat, especially around the flanks and neck, as labour intensifies.

Muscle Tremors: Some mares exhibit muscle tremors or twitching, particularly in the flank area, as contractions increase.

Increased Recumbency: Your mare might lie down and get up multiple times, trying to find a comfortable position as she experiences contractions.

3) Pelvic Relaxation

As the time for foaling nears, mares undergo various physiological changes to ensure a smooth birthing process. One of the most prominent of these changes is relaxation or softening of the pelvic area. ^[12]

The hormone relaxin plays an important role in this process. Produced in significant amounts during late pregnancy, relaxin helps relax muscles in the uterus and pelvic ligaments to facilitate passage of the foal through the birth canal. ^[12]

Additional changes observed prior to foaling include:

• Lengthening of the perineum, which includes the anus, vulva, and adjacent skin ^[2][10]
• Relaxation of the pelvic ligaments around the croup ^[11]
• Softening of the muscles surrounding the tail, resulting in little resistance when moving the tail
• Elongation of the vulva, potentially accompanied by vagin*l discharge 24 – 48 hours prior to foaling ^[10]

Figure 3: Image 1 shows relaxation of the perineum five days prior to parturition; Image 2 shows relaxation of the perineum in the hours leading up to foaling

4) Filling of the Teats

As the mare gets closer to parturition, the udder will continue to fill with milk. Pressure within the mammary gland increases, causing the teats to become distended or enlarged. ^[2]

This enlargement ensures that the foal can latch on properly and efficiently extract the vital colostrum and subsequent milk.

While the exact timing can vary among individual mares, filling of the teats typically occurs 2 – 7 days before foaling.

5) Abdominal Changes

Another sign that foaling is imminent is a noticeable change in the mare’s belly contour. This is caused by the foal moving into the proper birthing position within the uterus.

The mare’s belly will drop as the abdominal muscles relax, and a prominent point will form. ^[10] Some mares carry their foal off to one side throughout gestation, but the abdomen tends to become more symmetrical as foaling approaches.

6) Waxing on the Teats

Waxing refers to the formation of small, waxy, yellowish beads at the end of a mare’s teats. This substance is thickened colostrum, the mare’s first milk, which is rich in antibodies and other essential nutrients.

As parturition approaches, the mare’s mammary glands start producing colostrum. When the pressure within the udder increases due to the accumulation of this colostrum, small amounts may leak out and dry on the teats, forming a waxy substance that looks like hardened milk droplets. ^[2][10]

Between 70 – 95% of mares develop waxing on the teats before foaling. This sign is most common within 6 – 48 hours prior to foaling, but can occur as early as two weeks before foaling or not at all. ^[2][9][10]

7) Streaming Milk from the Teats

Within a few hours of foaling, your mare’s teats may begin dripping or streaming milk. Increased pressure in the teats results in colostrum leaking out. ^[2]

Keep note of how long this streaming occurs, especially if a large amount of colostrum is lost. In these cases, it may be necessary to supplement the foal with colostrum to ensure they receive adequate nutrition and to support passive transfer of immunity.

Figure 4: Image 1 shows waxing on the teats one day prior to foaling; Image 2 shows colostrum dripping from the teats the night of foaling

8) Changes in Body Temperature

Fluctuations in a mare’s body temperature can be used to reliably predict the onset of parturition. Research shows that average body temperature decreases by 0.3°C on the day of foaling compared to the five preceding days. ^[13]

A larger temperature drop may be a better indicator of impending labour. With a drop of 0.5°C or more, there’s a greater than 95% chance the a mare will foal within the next 12 hours. ^[13]

However, not all mares follow this pattern. One report describes an increase in temperature 90 minutes prior to foaling. ^[14]

If you are interested in using temperature changes to predict foaling, it is essential to measure your mare’s temperature regularly and at the same time of day to establish their average body temperature.

9) Changes in Milk Colour

The colour and consistence of your mare’s milk typically change one to three days before foaling. ^[17]

When the udder is first filled, the liquid will appear thin, clear, and watery. As foaling nears, the fluid becomes colostrum, a much thicker and stickier substance. ^[2] Some mares will produce colostrum with an amber or yellow color, while in others it will be white.

Figure 5: Image 1 shows milk secretions 10 days prior to parturition; Image 2 shows milk secretions hours before foaling

10) Mineral Content of Milk

The minerals provided in the mare’s colostrum and milk are essential for proper bone development in the newborn foal.

In the final two to four days before foaling, concentrations of calcium, potassium, and magnesium in your mare’s milk will increase while sodium and chloride levels decrease. ^[2][9][15]

By monitoring these predictable changes in your mare’s milk, you can anticipate the onset of foaling.

Research shows that changes in calcium carbonate concentrations can be used to determine when a mare is likely to foal. When calcium carbonate levels in diluted samples were below 200 ppm, 98% of mares did not foal in the following 24 hours. ^[10][16]

Measuring Changes in Mineral Content

The most cost-effective way to track changes in mineral concentrations is to use a water hardness test. ^[9] These tests are designed to measure the concentration of minerals, specifically calcium and magnesium, in water, but they can also detect changes in a mare’s milk.

As the mare nears foaling, there will be a noticeable increase in the milk’s calcium content. A sudden spike or consistent rise in calcium levels can signal that foaling is imminent.

While water hardness tests are easy to use and yield quick results, they are not specific to horses and are prone to interpretation errors. For this reason, you may prefer using an equine-specific test kit, such as Predict-a-Foal or FoalWatch, to predict the onset of parturition.

Predict-a-Foal

• How it Works: This test helps predict the likelihood of a mare foaling within 12 hours by detecting calcium concentration in the mare’s milk. A significant increase in calcium is associated with impending foaling.
• Procedure: The kit typically includes test papers that change color based on the calcium concentration in the mare’s milk. By comparing the color of the test strip with a provided color chart, one can gauge the calcium level and thus the likelihood of imminent foaling.

FoalWatch Test Kit

• How it Works: This kit measures calcium carbonate concentrations in the milk as a predictor of foaling within a certain timeframe.
• Procedure: The FoalWatch kit involves titration, a process where the mare’s milk is mixed with a reagent until a specific reaction (like a color change) occurs. The point at which this change happens gives an indication of the calcium concentration in the milk.

11) pH of Milk

In addition to changes in mineral concentration, the milk’s pH value also decreases as parturition nears. The initial milk produced in the udder is more alkaline (basic) with a pH around 8.0. As this liquids transitions into colostrum, the pH decreases to 7.0 or lower. ^[15] This timeline corresponds with the changes in milk mineral concentrations.

Given this predictable change in pH value, it can also serve as an indicator for the onset of the mare’s foaling.

One study reported that 80% of mares foaled within 24 hours when the pH of their milk dropped below 7.0. ^[15] In mares with a milk pH of less than 6.4, pH values were even more predictive with 96.3% of mares foaling in the following 24 hours. ^[17]

Measuring Changes in pH

The easiest way to measure the pH of your mare’s milk is to use pool test strips. While they are designed to measure pool water pH, these strips are sensitive enough to detect changes in the pH of mare’s milk. Many of these strips will also measure calcium hardness.

For breeders seeking more precision, pH probes offer a higher degree of accuracy compared to test strips. pH probes are electronic devices that provide digital pH readings, reducing the risk of interpretation errors.

Figure 6: Image 1 shows the pH of a mare’s milk 14 days prior to parturition; Image 2 shows the pH of the milk hours prior to foaling

Getting Ready for Foaling

As your mare approaches her predicted foaling window, ensure her environment is calm and safe and that you have all necessary supplies on hand to assist with the birthing process.

If your mare will be moving to a farm for foaling, it is recommend to move her several months ahead of her estimated due date. This will give your mare time to acclimate to her new environment and social group, helping to reduce stress. ^[2]

Giving your mare plenty of time to adapt to her new environment also ensures her immune system can produce antibodies to novel microbes or bacteria she may encounter. This will ensure your mare can pass on appropriate immune protection to her foal through immunoglobulins in her colostrum (first milk).

Whether you choose to have the mare foal in a stall or a pasture, ensure the area is clean, safe and comfortable:

• Sanitize the space to minimize the risk of infections.
• Remove any hazards and ensure the area is well-fenced and secure.
• If using a stall, provide ample bedding to cushion the mare and emerging foal.

Despite the best preparations, complications can arise. Familiarize yourself with signs of dystocia (birthing difficulties) and be ready to call your veterinarian if needed.

Preparing Your Foaling Kit

Assembling your foaling kit is one of the most important steps in preparing for the birth of your foal. This kit contains all the necessary equipment to you keep your mare and foal healthy and handle any emergencies.

Below is a list of some of the basic items your foaling kit may include. ^[18] However, there are many other items you might want to include. Discuss this list with your veterinarian as well.

Emergency Plan and Phone Numbers

Although most foalings go according to plan, it is always best to be prepared. Discuss different courses of action with your veterinarian ahead of time so you know what to do in case things go wrong.

Also, make sure to have your veterinarian’s phone number handy in case of an emergency.

Flashlight

Mares have a natural inclination to foal at night, an instinctive behaviour that is thought to provide protection against predators in the wild.

Given this, it can be helpful to carry a flashlight in your foaling kit. If your mare will foal in her stable, having a fixed light source may be better in case you need to intervene.

Thermometer & Stethoscope

It is important to monitor the vital signs of both your mare and foal in the hours and days following foaling. A fever is often one of the first indicators that something is wrong.

The normal body temperature for a mare and newborn foal are as follow:

• Mare: 99 – 101.5°F (37.2 – 38.6°C)
• Foal: 99.5 – 102.1°F (37.5 – 39°C)

Generally, it is recommended to take the foal’s temperature before the mare to avoid accidental transfer of bacteria on the thermometer.

You can also use a stethoscope to check your mare and foal’s heart rate. In equines, the the heart is located on the left side, just behind the elbow of the forelimb.

To measure the pulse, place the stethoscope against the skin and listen carefully for the heartbeat. An easy method is to count how many times the heart beats in 15 seconds and then multiply by four to get beats per minute.

If you do not have a stethoscope, you can also use your hand to feel the foal’s heartbeat in the same location.

The normal heart rate for a mare and newborn foal are as follow:

• Mare: 28 – 40 beats per minute
• Foal: 80 – 120 beats per minute

Soap & Paper Towel

Foals are born without a fully developed immune system, which makes it important to limit their contact with bacteria and other pathogens.

Prior to foaling, wash the mare’s vulva, udder, and teats with warm soapy water and paper towels to remove any dirt. This should be done gently as the mare’s mammary gland can be tender.

Gloves

Gloves are helpful to keep your hands clean and avoid introducing bacteria when washing your mare’s udders and vulva prior to foaling.

You will also want a pair of gloves for picking up the placenta and cleaning the stall after the birth occurs.

Tail Wrap

While not necessary, you may want to wrap the mare’s tail prior to parturition. Wrapping her tail will keep the hair clean and out of the way.

Mares that are not used to having their tail wrapped may be uncomfortable at first. Remove the wrap after foaling so it does not block circulation.

Some options to wrap the tail include vet wraps, standing wraps, or polo wraps.

Towels

Parturition can be a messy affair, so it’s useful to have towels on hand. After the mare has had a chance to lick and bond with her foal, you can use the towels to finish drying the foal off, particularly if it is born in inclement weather.

Naval Dip

After foaling, the umbilical cord should break and clot. Inspect the foal’s umbilical stump (naval) for any abnormal discharge or swelling.

If everything looks normal, you can dip the naval in a mild disinfectant solution, such as chlorhexidine, to prevent infection and promote the sealing of blood vessels within the cord. ^[18]

The easiest way to dip the naval is to fill a small disposable plastic container or paper cup with your disinfectant solution and dunk the umbilical stump. This should be done multiple times a day for the first few days.

Enema

The foal’s first feces is called meconium, a dark, thick, and sticky substance. Meconium is formed in utero and comprises sloughed intestinal secretions, amniotic fluid, cellular debris, and mucous. ^[19]

Due to its consistency, meconium can be difficult for the foal to pass. If not passed within 12 hours after birth, it can lead to meconium impaction, the most common cause of colic in newborn foals.

In such cases, an enema can be administered to help the foal pass the meconium. ^[19]

Scissors

In rare cases, the placenta will prematurely separate from the mare’s uterus, causing the foal to be delivered still enclosed in the placenta. This is known as a red bag delivery due to the red velvety appearance of the placenta.

A red bag delivery requires immediate action because the foal cannot breathe and is deprived of oxygen. ^[20] Whoever is overseeing the foaling must promptly cut open the placenta to enable the foal to breathe.

Caution must be taken to avoid cutting the foal. Some breeders prefer using a pocket knife or scalpel blade.

Twine and Palpation Sleeves

To avoid infection, the mare must pass her placenta within one to six hours after the foal is born.

It is important to let the mare pass the placenta on her own and not pull it out. Doing so could result in ripping the placenta, causing her to retain it. A retained placenta can have serious and sometimes fatal implications.

However, the placenta can be tied in a knot and held off the ground using twine. The knotted placenta should be tied above the hock to keep the mare from stepping on it and maximize the force of gravity.

As the mare starts to pass the placenta, continue to retie it above the hocks. If she is struggling to pass the placenta, a small weight (5 lb or 2.25 kg) can be added by tying a soaked towel or palpation sleeve filled with water or sand to the placenta.

Tying up the placenta also ensures that it stays in one piece so it can be evaluated later, if needed.

Stages of Parturition

Parturition, or the process of giving birth, is broken down into three distinct stages. Understanding these stages and the typical progression of the birthing process, will help you intervene quickly if complications occur.

Stage 1: Labour

In the first stage of parturition, the mare begins experiencing contractions and the foal moves into the foaling position.

The length of labour varies greatly between individual mares. Many different factors impact how long labour takes, including the number of previous pregnancies a mare has had. ^[2]

Most mares labor for between 30 minutes to 4 hours, with signs that resemble colic, including the following: ^[2][21]

• Restlessness
• Pacing
• Looking at her flank
• Raising/swishing her tail
• Urinating frequently
• Sweating
• Lying down and getting up.

This stage of parturition ends with the rupturing of the chorioallantois, a membrane that surrounds the developing fetus inside the uterus. The chorioallantois plays a vital role in the exchange of gases and nutrients between the mare and her developing foal.

When a mare is about to give birth, the rupture or tearing of this membrane results in the release of the allantoic fluid — a phenomenon commonly referred to as the mare’s water breaking.

Stage 2: Delivery of the Foal

The next stage of parturition is the delivery of the foal, usually lasting between 15 – 30 minutes.

Call your veterinarian if it has been longer than 30 minutes since the chorioallantois ruptured and the foal is not progressing. This may indicate a complication that requires intervention.

The foal should come out front hooves first, followed by their nose, in what is referred to as a diver’s position. Any other presentation indicates dystocia and requires a veterinarian to be contacted.

Also contain your veterinarian if the mare is straining or shows signs of distress during delivery. If the foal experiences any complications or trauma during parturition, it is important for your veterinarian to examine them for signs of neonatal maladjustment syndrome or dummy foal syndrome.

A thin, white membrane called the amnion will cover the foal during delivery. The amnion breaks easily as the foal moves. However, if the amnion covers the foal’s nose, it should be removed to prevent suffocation. ^[22]

This stage of parturition ends when the foal is expelled.

Stage 3: Passing the Placenta

After the foal is delivered, passing of the fetal membranes (placenta and amnion) is important to safeguard the mare’s health and allow her to breed again in the future.

If she does pass the placenta shortly after birth, tying it up and adding a light weight can help her pass it faster. If she has not passed it after three hours, your veterinarian may administer oxytocin to stimulate uterine contractions. ^[23]

The placenta should be examined to evaluate uterine health and for signs of placentitis. The weight of the fetal membranes can also be used to estimate the foal’s weight. Usually, fetal membranes weigh approximately 10% of the foal’s birth weight. ^[24]

Post-Foaling Care

Be cautious when entering the mare’s stall while she is in labour or after foaling. Some mares are very protective of their foals and will display aggressive behaviour. Never put yourself between the mare and the foal.

The mare should be allowed to bond with her foal, but it’s also crucial to monitor both for any signs of distress or complications.

Once the foal is born, ensure it’s breathing and standing within a few hours. The foal should start nursing soon after standing, getting colostrum from the mare, which provides vital antibodies.

Within 24 hours post-foaling, have a veterinarian examine both the mare and the foal to ensure they are healthy.

Colostrum

It’s important to ensure that your foal gets enough colostrum from their dam to support immune system development and protection from disease.

Colostrum is a highly nutritious form of milk produced by the mare when a foal is born. This early milk is rich in fat, protein, lactose and minerals, and contains almost three times more vitamins A, D, K, and C than mare’s milk. ^[6][8]

Most importantly, colostrum is a source of immunoglobulins (antibodies), which help build the foal’s immune defenses. Foals are only able to absorb maternal antibodies through their small intestine within the 24 hours of life.

If a foal does not receive enough immunoglobulins during this critical time, failure of passive transfer can occur and the foal may be at risk of developing serious infections or diseases.

Consult with your veterinarian if you are concerned about your foal’s colostrum intake. Your veterinarian may perform an IgG test to assess passive transfer and determine whether donor colostrum or another intervention are required.

Nutrition Considerations for Pregnant Mares

It is important to pay close attention to the nutritional needs of your pregnant mare to ensure she is prepared for the demands of foaling and lactation.

Your mare’s nutrition requirements do not change until about the fifth month of gestation. However, after five months, her energy and protein needs will continue to increase until mid-lactation. ^[25]

The biggest increase in your mare’s nutritional requirements will occur in the last trimester of gestation, during which 75% of fetal growth occurs. She will also require more of certain vitamins and minerals that are essential for proper fetal development.

Special care must be taken when formulating a diet for late gestation. It’s important to strike a balance between providing adequate calories without overfeeding, which can negatively impact the foal’s development and put extra strain on the mare. ^[26] Calories should come from fat and fiber sources rather than starch and sugar (non-structural carbohydrates).

A well-balanced diet not only supports the mare’s overall health but also gives the devolving foal a healthy start to life. Nutrient deficiencies or imbalances can lead to complications during pregnancy and birthing, or post-foaling challenges.

Mad Barn’s Omneity is a balanced vitamin and mineral supplement formulated to provide nutrients commonly lacking in the equine diet. Feeding your mare Omniety will support fetal development, help your mare bounce back from foaling, and provide the newborn foal with high quality milk.

Summary

With so much variation in equine gestation periods, predicting the exact date of foaling can be difficult. Each mare is an individual and no two foalings are the same.

Paying attention to the signs of foaling listed above will help you prepare for the arrival of your new foal, and ensure that both the mare and foal receive the best care possible.

It’s also important to know what is typical for your mare and to watch for deviations in her normal behaviour. Not all mares follow the same progression in changes prior to foaling.

Prepare your foaling kit and work closely with your veterinarian to make sure you are ready for every eventuality before parturition begins.

Well before labour begins, you should also work with a qualified equine nutritionist to design a balanced feeding regimen that optimizes both mare and foal well-being.

Submit your mare’s diet online for a free consultation to get individualized feeding and management recommendations from our expert nutritionists.