Table of ContentsBy Michelle Abraham, BVMS, Resident in Large-Animal Medicine, Penn Vet’s New Bolton Center Published Mar 12, 2014
As we wait for our mare, My Special Girl, to give birth to her foal on the live New Bolton Center Foal Cam, we would like to explain what could happen during the foaling.
Read about My Special Girl and her special foal in February’s Penn Vet Extra. Watch her on the live Foal Cam at www.vet.upenn.edu/foalcam.
Trying to pinpoint a mare’s foaling date is challenging because the mare’s gestation period is one of the most variable, stretching from 10 ½ to 13 months. The average gestation is about 11 months.
My Special Girl’s due date is March 14, when the foal reaches its 340th gestational day. Will My Special Girl give birth on her Friday due date? Based on the clinical signs, probably not. Our veterinarians expect her to carry this foal beyond her due date. Although it is unusual for a mare to foal without any external signs, it certainly can happen, so they will be ready when she is ready to have this foal.
In the late stage of gestation
Mares can display a variety of behaviors in the weeks just before giving birth. Mild, intermittent discomfort throughout the day or night is normal in some mares, and often coincides with activity of the foal. During these times, if you watch the mare’s flank region closely, you’ll often see the foal move.
At the time of foaling
There are three stages of parturition (giving birth):
Stage 1 is the period of uterine contractions that initiates foaling. This is the most variable stage and can last for hours in some mares. Typical signs in the mare of stage-one labor can include: restlessness in the stall, getting up and down, sweating, curling of the top lip, pawing, weight shifting, picking up of the hind legs, tail swishing, and frequent urination and defecation. However, some mares only alter their routine slightly, and others show no signs at all.
Stage 2 starts with the rupture of the chorioallantois, which in humans we refer to as ‘water breaking.’ At this time, movement of the foal through the pelvic canal commences. The foal should present with two front legs (one extended slightly in front of the other) with the nose resting between them, at about the level of the foal’s knees. The heels of the front hooves should be facing the ground and the top of the foal’s head and the foal’s back should be towards the mare’s back. Uterine contractions and active abdominal contractions push the foal along. The foal is typically delivered 10 to 20 minutes following rupture of the chorioallantois.
Stage 3 is the passage of the fetal membranes. The placenta and other membranes should be completed within three hours of the foal being born. Often mares will show some degree of discomfort from the uterine contractions.
Veterinarian involvement during birth
Monitoring: With close monitoring, we are able to detect some of the more subtle signs of labor. Some things we look for include: mammary gland development and filling of the teats, waxing (crystallized colostrum) on the teats, dripping/streaming milk from the teats, and relaxation of the muscles around the pelvis. We regularly look at the mare’s mammary gland, occasionally palpate the udder, lift up her tail to examine the vulva, and palpate the muscles over the pelvic region.
Preparation: During stage one, we typically wrap the mare’s tail. This serves two main purposes: it keeps the tail out of our way during delivery, and it also keeps the tail clean.
Assessing the foal’s position and presentation: When the ‘water breaks,’ we check the foal’s position and presentation. We do this immediately because if there are any abnormalities in the position of the foal, it is more easily corrected before the foal moves through the pelvis.
Collecting fetal fluids: We collect a sample of the fetal fluids for analysis to help us understand what may have gone wrong if the mare or foal is abnormal.
Delivery of the foal: After checking the position and presentation of the foal, we will let the mare progress through stage two. As the legs appear through the vulva and the mare is lying down and actively pushing, we grasp the foal’s front legs and give the mare a little assistance. As she pushes, we place gentle traction on the foal. In normal mares and foals, we do not forcibly pull the foal out, because this can cause damage to the mare and interfere with the natural birthing process. As the nose starts to appear through the vulva, we will remove any of the fetal membranes that are covering the nose, which may obstruct the foal’s breathing. Additionally, our gentle traction can prevent the foal’s nose from being drawn back into the vulva, which also may interfere with initiation of the foal’s breathing. The widest parts of the foal to fit through the pelvis are the shoulders, so once they pass through the pelvis, we release our traction and the foal usually is born.
Many actions happen simultaneously once the foal is born.
--We check the foal’s heart rate to ensure it is breathing spontaneously and to assess its level of activity. We like to see a foal’s initial heart rate above 60 beats per minute and to see the foal active within minutes of birth.
--We look to see if the foal is holding its own head up and how responsive it is to stimuli.
--We listen to the lungs with a stethoscope. Initially we expect to hear some crackles and moist sounds, but these should disappear quickly. As the foal takes its first few breaths, breathing may appear a little irregular and fluid can be seen clearing from the foal’s nostrils.
--We take a blood sample from the foal’s umbilical cord for analysis.
--We look for rib fractures, which can occur as the foal passes through the birth canal.
--We look for any obvious congenital problems, such as limb contracture (flexion) that may make it difficult for the foal to stand.
--We test the quality of the first milk (colostrum) because this provides the foal with essential immune protection. If colostrum quality is low, we can provide a supplement.
Time for bonding: We value the importance of the bond between the mare and foal, so once everything looks good, we like to leave and observe from outside the stall. During the bonding process, the mare will lick and nuzzle the foal. It may look like the mare is biting the foal, but this is not the case.
Some mares stand up immediately after the foal is born, and others remain lying down for a period of time. In some cases we will move the foal to the mare’s head, which will allow her to remain lying down while still being able to bond with her foal. Some mares will show discomfort as uterine contractions continue after the foal is born and the fetal membranes are passed.
The foal stands: Attempts to stand often start 30 minutes after the foal is born. The foal will likely make numerous attempts to stand. This is an important process that allows the foal to develop its coordination, balance, and strength. It is very unusual for a foal to get injured during this period, particularly while being observed. Occasionally a foal will get itself into a position that makes it difficult to continue attempting to stand, or it may get tired, so we may enter the stall to move the foal into a new position or give its hind end a boost. We want the foal to save some energy as it learns to nurse.
Nursing: The foal should nurse within two hours of birth. Watching a foal learn to find the mammary gland and nurse is always interesting. Foals develop their suckle reflex soon after birth, usually within 20 minutes. Some will start exercising their suckle reflex on their own legs, on the wall, or on various body parts of the mare. The mare’s behavior during this process can vary greatly. Some seasoned mares position themselves for the foal, while other mares need a little more time to get used to the foal as it learns to coordinate its suckle and tongue curl. It is normal in many mares to see them move around and sometimes lift a hind leg and ‘squeal.’ The mare will often nicker to the foal and nuzzle or lick the foal during this process. Table of Contents