Foaling Basics

For responsible breeders, foaling is the culmination of many months of careful planning.

Whether to foal indoors or outdoors is a personal choice based on many factors, including climate, time of year, and facility. Foaling indoors may allow for superior monitoring and protection from the elements, whereas foaling outdoors may be cleaner and the mare's ability to move unrestricted may help facilitate a smoother foaling.

Although most foalings are normal and therefore do not require human intervention, it is still imperative that foalings be attended so that any problems can be addressed quickly.  Once the mare's water breaks, her foal is usually born within just twenty minutes.

A famous retrospective study published in 2007 reported that for every ten additional minutes that pass beyond thirty minutes of waters breaking, the foal's risk of nonsurvival increases by 10%. This data doesn't mean that an attendant should drag their foal out of the mare, it simply illustrates that timely intervention is critical when problems arise.

To ensure that foalings are attended, many breeding farms employ a person to watch their mares overnight. This person is generally referred to as the foaling attendant or nightwatch. When the foaling attendant has the right combination of knowledge, experience, intuition, and dedication, and if they are not exhausted or task-loaded, live observation is the best method for identifying a foaling mare and for ensuring that the birth is attended. Additionally, the utilization of cameras for remote monitoring ensures minimal interruption to the mares.

For farms that choose not to have someone watching their mares overnight, there are several options available to help them predict foaling. One of the most reliable prediction tools is a combination of pH and calcium testing of the mare's mammary secretions; a small sample is collected from the udder and placed on a test strip, the results of which help predict if a mare will foal or not. Keep in mind that this method is not infallible.

Other monitoring options include a variety of transmitters that are affixed to the mare's vulva, tail, halter, or a surcingle, which theoretically send an alert when a mare is foaling. The major downside to using one of these devices is that they may not alert early enough for optimal intervention when there is a problem.

While there are no absolutes in foaling, most mares undergo a myriad of physical changes as foaling approaches. The udder may enlarge and the teats may fill. Colostrum may accumulate on the ends of the teats, resembling candle wax. The wax may change from an amber color to a milky white. The mare may drip or stream milk. As her ligaments and muscles relax in preparation for foaling, the mare's croup may appear sunken, her belly may appear dropped, her vulva may elongate, and she may have less resistance when her tail is lifted. A plaque of ventral edema may develop on the mare's belly and her legs may stock up.

Horses have three stages of labor. In the first stage, the mare's behavior may change due to discomfort from the contractions that are beginning and her foal moving into the correct orientation for birth. This stage generally lasts a few hours. Any colic-like symptoms may be indicative of first stage labor: flehmaning, pawing, circling, pacing, rolling, etc. She may go off her feed or develop loose manure. When foaling is imminent, she may sweat and steam, which can make her veins appear more prominent.

First stage ends and second stage begins when the water breaks. In horses, the water breaks when the chorioallantois ruptures, not the amnion. The attendant may elect to wrap the mare's tail to facilitate optimal visualization of the foaling process, to improve cleanliness, and to prevent tail hairs from being pulled into the reproductive tract in the event of a dystocia. If a farm has access to supplemental oxygen, it should always be brought to the foaling area so that it can be accessed swiftly if needed. Other tools that an attendant might use include obstetrical chains, straps or ropes, and towels.

Ideally, the attendant should check that the foal is in the diving configuration as soon after water breaks as is safe. When the foal is not in the diving configuration, with one front leg slightly in front of a second front leg and then the nose, it is called maldisposition. Checking for maldisposition before the mare starts pushing and before parts of the foal are visible outside of the mare's vulva enables any problems to be fixed before the foal is jammed up into the birth canal.

Once the foal is born, the attendant should ensure that the amnion is not covering the foal's nose. They may elect to give a prophylactic enema to help the foal pass its meconium so that it is not distracted from nursing later on. The attendant may use a Brix refractometer to test the mare's colostrum and they may tie up the mare's placenta so that she does not step on it. The attendant should also dip the foal's navel when the umbilical cord breaks. Although there are several studies that investigate different navel dip products, none of them compare different protocols, so the breeder should decide with their veterinarian what product and protocol is best for their unique situation.

Most foals will stand within one hour of birth and nurse within two hours of birth. Foals receive their early immunity from ingestion of colostrum, and the window wherein a foal can absorb antibodies from the colostrum is small, so this timing is critical. A large study published in the late 1970s found that foals who had a delay of 4 hours or more from birth to first dose of colostrum were ten times more likely to have a foalhood infection.

Additionally, a recent study published in 2022 found in dairy calves that for every hour of delay between birth and first dose of colostrum, odds of developing an external navel infection increased by 1.15 times. While foals are not calves, this particular trial is compelling because IgG, stall cleanliness, and navel dipping were all taken into consideration, yet timing of colostrum consumption was the only factor found to be associated with navel infection. This of course does not mean that the attendant should disregard the importance of IgG, stall cleanliness, and navel dipping, rather it is a reminder that timing is important.

The foal's IgG should be tested around 8-12 hours after birth so that the foal can be supplemented orally with thawed banked colostrum if it is found to be deficient, otherwise intravenous plasma will be required.

When the foal is born, second stage labor ends and the third stage begins. Third stage ends when the mare passes her placenta, which should occur within three hours of foaling. A placenta that is not expelled by three hours after foaling is considered retained. The attendant should initiate treatment when a placenta is retained to prevent infection, which can be deadly. The attendant should never pull on the placenta, and extreme caution should be exercised when adding weight to a retained membrane, as this may cause invagination of a uterine horn, which can result in colic, necrosis of the uterus, or uterine prolapse.

When the mare does pass her placenta, it should be carefully examined to ensure that no pieces are left behind in the mare. Any lesions found on the placenta may offer insight into the health of the newborn foal and may reveal potential issues that need addressed with the mare during future pregnancies.

At the end of the day, a smooth foaling is mostly up to the horses and a bit of luck, but there are many things we can do to help ensure our mares and foals are set up for success.