Problems with the foaling process are termed dystocia. Dystocia can be catastrophic and costly through loss of the mare or her future fertility and/or loss of the foal. Parturition (foaling) occurs more rapidly in mares than in most other domestic species (minutes vs hours). The sooner dystocia is detected and corrected, the less chance of catastrophic results.
Causes of Foaling Problems
A common type of dystocia occurs when a front foot or the head is turned aside before the foal enters the birth canal, blocking the foal's passage. Signs of this may be obvious, subtle or sometimes impossible to detect. In this situation, an experienced veterinarian or an "equine midwife" (a person who has assisted at many mare foalings) can be invaluable. If the dystocia is quickly detected and the diverted foot or head is redirected into the birth canal, the foaling proceeds normally. However, if the problem is not detected or corrected and the mare continues in her attempts to expel the foal, the dystocia becomes more dangerous for both mare and foal.
The second type of dystocia involves some abnormality, such as abnormal presentation of the foal (such as the back appearing at the birth canal), an abnormally large foal, a deformed foal, an abnormal birth canal (such as scarring or a bony abnormality), or some other abnormality in the mare (such as ventral hernia or uterine torsion).
Signs of Dystocia
In a normal foaling, the mare's uterine contractions cause the fluid-filled chorioallantoic sac to rupture ("breaking water"), after which the foal's front feet appear in the birth canal. Mares usually then lie down and begin contractions that expel the foal within about 15 minutes. Most mares pass the placenta within an hour after foaling; the placenta is considered retained if it has not passed within 3 hours. Save the placenta in a cool place for examination; do not allow access by dogs or other animals.
There are 3 important signs that foaling is not proceeding normally after breaking water. Remember that the foaling process in mares is a rapid event and that any problems that require intervention need to happen in a timely manner. Observation of any of the following signs, means veterinary assistance is required. If waiting for your veterinarian to arrive, unless instructed otherwise by your veterinarian, get the mare up and walking, as this will slow the uterine contractions. If the mare is to be transported to an equine hospital, have your truck and trailer ready to go in advance.
- More than 15 minutes have elapsed since the mare has broken water, but the foal has not yet been delivered.
- The mare is in hard labor for an extended period of time and no progress is made.
- Only one leg is protruding from the vulva, and no more of the foal has appeared over the past 15 minutes.
The mare has not broken water, but a crimson mass appears at the vulva. This is the entire placenta being passed with the foal. The placenta must be quickly cut open so foaling can proceed and the foal can breath oxygen.
Considerations in Correcting Dystocia
Viability of the foal:
A normal foal can remain alive for up to 60 minutes after the water breaks. However, remember that an abnormal or already dead foal causes most dystocias.
Your veterinarian will usually attempt to manually correct a dystocia for several minutes before considering another approach. These subsequent approaches depend on how long the dystocia has been present, whether or not the fetus is alive, the prognosis for the mare's survival, the prognosis for the mare's fertility, and the time it takes to accomplish the procedure.
The following is a list of some of the common alternative approaches, whenever your veterinarian must resort to any of these procedure, the risk to both mare and foal increases substantially:
- General anesthesia:
- After rapid intravenous infusion of an anesthetic, the mare's hind legs are lifted using hobbles, rope and a block and tackle. The foal can then be more easily repelled back into the uterus, repositioned and possibly delivered. It may be appropriate for you to prepare for this sometimes life-saving procedure by having hobbles, ropes and a block and tackle available, or a front-end loader will be needed to lift the mare.
- If the fetus is dead, it may be necessary to surgically remove part of the dead fetus (fetotomy) to allow passage through the birth canal.
- Cesarean section:
- Cesarean section involves removal of the foal through a surgical incision in the mare's abdomen. This is a major surgical procedure. This procedure requires rapid action at a surgical facility that can mobilize quickly for such an operation.
Post Foaling Complications:
I recommend that all mares and their foals receive a post foaling examination and that you consult your veterinarian in advance as to the timing of this exam.
The mare that retains its placenta must be monitored for passage of the placenta, and then treated appropriately to prevent complications. Call your veterinarian should you have a retained placenta, as this can be dangerous situation for your mare. Additionally all mares must be observed for such complications as rupture of an internal artery, large colon torsion and laminitis. Continued sweating, reduced interest in the foal, and persistent colic indicate a problem in the mare. Mild colic from uterine contractions is normal after foaling, but not severe or persistent colic. The mare may be normal just after foaling but then may begin to sweat and show colic. Hot feet and constant shifting of weight, usually beginning 24 hours after foaling or later, indicate laminitis.
If you have any questions concerning foaling and foaling problems you should consult with your veterinarian. If you know in advance that you are not prepared to handle the possibility of a foaling emergency, you should talk to your veterinarian about options for having the mare deliver her foal in a foaling facility that is equipped to handle these situations.