Stacie’s second health column in the Breeders 2021 issue of Montana Horses magazine walks breeders through a normal foaling: predicting when a mare will deliver, the three stages of parturition, and the critical timeline for a newborn foal. The magazine has since ceased publication and its online archive is gone, so the column is reproduced here in full. Foaling-position diagram in the print edition by Dr. Maria Schnobrich.
What to Expect in the Foaling Process
By Stacie G. Boswell, DVM, DACVS — Montana Horses, Breeders 2021 issue, pp. 36-37
This article is provided for general information only. It is not a substitute for veterinary examination, diagnosis or treatment. Please consult a licensed veterinarian before beginning any treatment or making decisions about your horse’s care.
The text below was read from the printed magazine using optical character recognition and lightly edited for the web, so that this article can be found and read online. The original article as it appeared in print is reproduced at the foot of this page and is the version of record — where the two differ, the printed version is correct. If you spot an error, please let us know.
Spring is upon us, and foals will be entering the world very soon. Problems are rare, but can mean loss of life for the foal and/or the mare. Therefore, attending the foaling is advisable so that assistance or veterinary care can be provided as soon as possible. Here are some guidelines for what is expected from parturition (foaling or birthing process).
Predicting arrival
Mares are pregnant for 342 days on average, though a normal foal may be born up to two weeks before or after this expected due date. Most fetal growth happens in the third trimester, so it may not be outwardly noticeable that a mare is pregnant until the tenth or eleventh month of pregnancy.
Development of udder begins about six weeks prior to parturition, and peaks the evening prior to foaling. There are test kits which use a few drops of milk to predict foal arrival. These are 90% accurate in predicting foal arrival within three days. Mares may “wax” or leak colostrum (first milk) anywhere from six to forty-eight hours prior to foaling, though this may not occur at all. Foals are typically born at night, most often between midnight and 4:00 AM. Predicting birth helps you know what nights to stay up and watch but minimize your sleep loss.
Hormonal changes signal the birthing process. One hormone (relaxin) will cause her vulva to elongate. She will also develop loose, jiggly muscles through her croup and tailhead. This sign, along with milk development and changes, help us know when a foal’s birth is imminent.
Entry into the world
Stage one of parturition is subtle. The foal will move into position. He must be healthy and have normal limb development in order to actively move into the correct position for birth. Developmental deformities or infections in the womb can result in malpositioning.
As the foal moves into position, a mare will show signs of colic or abdominal discomfort. She may lay down and get up repeatedly, roll, paw, sweat, or turn her head to watch her flank.
Stage two begins when her “water breaks.” The first visible part of the foal will be his front hooves, and shortly thereafter, his nose. He should be completely out after about thirty minutes of active, hard labor. The mare and her foal may then rest for ten to twenty minutes. The foal will soon attempt to stand up, and should achieve this feat within an hour of being born.
Foals normally have a suckle reflex at birth, but they are uncoordinated. Initially, a foal may try to suckle his mother’s elbows, shoulders, and hind legs. An experienced mare will guide her foal to the correct location. The first time he latches on will be only for a second or two.
A foal should suckle within two hours of being born. It’s critical that a foal suckles within this short time window because that is how he acquires immunity. If he doesn’t suckle, he will have a dysfunctional immune system (think: the “bubble boy”) and will quickly succumb to an infection such as pneumonia, infected joints (“joint ill”), or an infected umbilicus (“navel ill”).
A foal should defecate within two hours of suckling. The meconium is the first feces that a foal expels. It appears as dark, tarry pellets. About one to two percent of the time, this is delayed and a foal develops a meconium impaction, which requires veterinary treatment.
Stage three is marked by the passage of the placenta or afterbirth, which should be within three hours of the foal’s birth. This event is closely associated with the foal suckling, because as he suckles the hormone oxytocin is released. This hormone causes milk to be released, and simultaneously signals the muscles lining the uterus to contract, which results in expulsion of the placenta.
Foals are so much fun, and hold so much promise. Understanding what to expect during foaling is critical for a successful foaling season.
Dr. Stacie G. Boswell is a veterinarian board-certified in large animal surgery and has an interest in equine welfare. She practices in Belgrade, MT and is the author of The Ultimate Guide for Horses in Need.
The article as it appeared in print:
Montana Horses magazine is no longer published and its online archive has been removed. An archived copy of the Breeders 2021 issue’s listing is preserved by the Internet Archive.
The Ultimate Guide for Horses in Need is available directly from Stacie or from Trafalgar Square Books.