Foals born before the day mark to healthy mares rarely survive, in part because surfactants, which assist with development of the respiratory system, do not work as they do in women. Mares with a problem, such as placentitis, may have an abbreviated gestation that ends in a viable foal, as elevated cortisol can hasten fetal development and better prepare it for survival. Those foals born between and days frequently require neonatal intensive care, usually in a veterinary hospital, but high-quality nursing often sees these foals through.
Foals born after days of gestation generally do not present a problem, and some are smaller than expected, having been the result of delayed uterine development. Prolonged gestation may be caused by endophyte-infected fescue toxicity, which is common in certain areas of the country when mares are grazed on fescue pasture or fed fescue hay.
Fescue should be removed from the diet two to three months before the due date. Fescue toxicity may prolong gestation but it also have other effects, such as a thickened placenta and reduced milk production.
Milk production can be induced through the use of domperidone, a medication known as a dopamine antagonist, beginning days before the expected due date. Mare owners sometimes ask about inducing labor in overdue mares.
Unless the mare is in danger, most veterinarians will not induce labor, as the likelihood of foaling problems escalates, and foal health is usually compromised to the point that intervention by trained critical care veterinarians and support technicians would be necessary for its survival. The nutritional management of foaling mares revolves largely around the provision of an energy-dense diet that includes a complete complement of vitamins and nutrients.
In addition to a base diet of good-quality forage and fortified concentrate, nutritional supplementation can help certain mares.
The average length of pregnancy in mares is about days, but this can vary by a couple weeks in either direction and still be considered normal. Some mares have a tendency to have longer or shorter pregnancies year after year, while others are more unpredictable. In general, however, a foal born at or before days of gestation is considered premature. In general, the closer the birth is to or more days, the better the chance is that the foal will live.
However, many premature foals do well with supportive care, eventually growing as well as full-term foals and catching up by or before two years of age. What are the problems to be aware of? Why was the foal delivered prematurely in the first place? In this article, we will define what a premature foal is, describe the complications that occur with premature foals and their treatments, and also describe some of the reasons premature foals are delivered so early.
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Favorite Share:. What Is A Premature Foal? Sign Up Already have an account? Exposing bred mares to artificially lengthened days during the latter third of gestation has been shown to shorten gestational length by about 10 days.
Early Signs. The signs of impending parturition are about as variable as gestation length. Although mares show a tremendous amount of variation, many do repeat their foaling behavior year after year.
Classical signs of approaching parturition include udder development, beginning 2 to 6 weeks before foaling. Milk is let down into the teats teat distension 4 to 6 days prior to parturition. At this time, some mares will have occasional dripping or streaming of colostrum. If this streaming is continuous, collect and store the colostrum for possible use with the newborn foal. In addition to changes associated with the mammary gland, muscular relaxation in the pelvic region occurs progressively during the last 7 to 14 days of gestation.
Many mares show these classic signs of approaching parturition, which makes it fairly easy to determine their foaling time. On the other hand, some mares will break all the rules and these signs may not be present, or may appear at varied times. Furthermore, maiden mares mares having their first foal may show all or none of these signs. Predicting Foaling Time. Help is available for those with mares with unknown foaling history or mares which are unpredictable for some reason.
Several commercial kits to estimate foaling time are available. These test kits are based on the fact that in most mares, calcium and magnesium concentrations in pre-partum mammary secretion rise progressively during the latter portion of gestation to the time of foaling. A majority of mares show a significant rise in calcium and magnesium concentration just prior to parturition.
This allows foaling attendants to estimate time of foaling within 12 to 24 hours. The kits have been most useful in determining when the mare will not foal.
In other words, if the test shows no changes in the calcium concentration, the mare probably will not foal within the next 24 hours, and thus would not need to be watched as closely.
When a rise in calcium is indicated, direct more attention to the mare. These test kits, available from veterinarians and veterinary supply companies, are simple to use and fairly inexpensive. All kits require taking 1 to 4 cc of milk daily once classic signs of approaching parturition are seen. Generally, take samples for approximately 10 days. Recent research has shown daily samples collected during the early evening hours adequately detected the pre-partum calcium rise.
Various other types of mechanical foaling predictors are available. These predictors set off alarms when it appears the delivery process has begun. One foaling predictor alarm system sets off a page when the mare is in a horizontal position. The alarm is set off, when the delivery process has begun. Both systems can be programmed to call phone numbers. Parturition — Stage I.
Parturition typically is broken down into three stages. Stage I, normally lasting 1 to 4 hours, reflects the initial uterine contractions and final positioning of the foal for delivery.
These contractions will make the mare appear nervous and uncomfortable. Typically the mare will exhibit the following behavior:.
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