EQUINE HEALTH

By HEATHER SMITH THOMAS

Most pregnancies in mares are normal and everything goes smoothly at foaling time. There are a few situations, however, when a mare has a serious problem following the birth of her foal. You need to be aware of it so assistance can be given, to try to save the mare, or to make sure her reproductive tract can heal and recover so she might be able to have future foals. Dr. Ahmed Tibary, DMV, Dip. ACT Professor of Theriogenology, Depart- Equine Care ment of Veterinary Clinical Sciences, Washington State University, says breeders need to be aware of things that can go wrong after the mare delivers the foal. The third stage of labor is when the mare sheds her placenta. “As a rule, we like to see that happen within three hours or less. Most mares, if there are no complications with foaling, will deliver the placenta within the first hour, and often very soon after they get up,” says Tibary.

“Some people like to give a mare oxytocin after foaling to help stimulate faster shedding of the placenta, but I caution people against giving the mare oxytocin immediately or even within an hour of foaling, even if they are concerned about a retained placenta. Give her

Equine Care some time; let her bond with her new foal. If the foal is nursing, this stimulates release of natural oxytocin in the mare (and triggers milk letdown and uterine contractions to help shrink up the uterus and shed the placenta). This is generally enough stimulation,” he says. “I have had some cases in mares in which the placenta was retained for more than 18 hours, and any time it takes more than three hours, this becomes a big risk for health of the mare. When a mare does shed the placenta, it’s important to know that it is all there (with no pieces still within the uterus). It takes some experience or training to know how to check it yourself. It is important to do this or have an experienced person check it to make sure it is all there. There might be a small piece left in the mare, and that’s enough to cause a lot of problems (such as a serious uterine infection, or founder),” he says. “One procedure I always recommend after every foaling is to gather the placenta as soon as it is delivered, put it into a clean container and put it in the refrigerator to keep it fresh for the veterinarian to look “I have had some cases in mares in which the placenta was retained for more than 18 hours, and any at. Your vet can check it time it takes more than three hours, this becomes a big when he/she comes to the farm to examine the mare risk for health of the mare.”—Dr. Ahmed Tibary and foal at some point during the first 24 hours. We can Some people might think the foal is doing fine and check the placenta at the same time we do the first health that they don’t need a health check because the foal check on the new foal—unless there is some reason we looks good and mare had an easy foaling, but it is still a need to check the mare or foal quicker,” says Tibary. good idea to have a routine health check. “I read some“For the foal, we like to check it any time between 12 where that there is no such thing as an easy foaling beto 18 hours, because by then we can include checking cause no one has asked the mare. Many times we see (above) torn vulva for failure of passive transfer (to know whether or not mares that don’t seem to have had any problems at all, (below) Uterus after the foal received adequate antibody levels from but when we examine them after foaling or to see if they severe hemorrhage colostrum),” he explains. can be rebred at foal heat, we find a torn cervix or an area of damage in the vagina—something that wasn’t externally obvious,” he says. Some post-partum problems show up immediately, however, for instance if the mare’s vulva is torn, or she is bleeding. There are several categories of post-partum problems. One category includes emergencies that may be life-threatening for the mare or foal. “These problems are generally signaled by the mare—such as rejection of the foal, or the mare continuing to strain, or she’s still bleeding, or there is an obvious tear in the vagina, or she has retained the placenta, or she starts trembling or showing signs of colic. There is a long list of problems that can have the same signs,” he says. TIBARY PHOTOS “We may see a dull mare that is too quiet and depressed, or colicky. Studies have looked at all the postpartum problems and emergencies received in large

hospitals, and some of these are related directly to the reproductive tract and include tears in the uterus, metritis (uterine infection), severe toxemia, etc. There are other problems involving the urinary system or the gastrointestinal tract,” says Tibary.

Some mares experience large colon volvulus, and this happens most often in large mares after foaling. This is when the large colon flips over on itself—perhaps because there is suddenly more space after the foal is born and creates a twist and blockage. “There can also be bladder tears, and most of these conditions cause discomfort and the same clinical signs—colic and depression,” he explains.

“Another problem we sometimes see is artery ruptures and bleeding into the uterus or into the broad ligament supporting the uterus. Most of the severe problems that are emergencies occur immediately after foaling or within the first 48 hours.”

It is important to find the cause of the mare’s dullness and discomfort, to know how best to deal with the problem. “If the mare is rolling continuously, trembling, etc. this is definitely an emergency and requires a thorough examination. Most emergency situations are best handled in a referral hospital, since these mares often need to be hospitalized—to care for them properly,” he says. It can be difficult to take care of both the mare and the foal otherwise.

Emergencies could include severe accidents such as a prolapsed uterus, prolapsed rectum (both of which are rare), prolapsed or inverted bladder, severe rectal-vaginal tears (as when the foal’s foot pushes through the vagina into the rectum), severe bruising or laceration of the vagina, etc. “These can be complicated if the mare becomes infected, or can become aggravated by severe inflammation,” says Tibary.

The original problem can lead to other problems. For example, simple vaginal bruising that is painful may prevent the mare from urinating or defecating–because it hurts. The mare becomes impacted, and this secondary problem may eventually be worse than the primary problem.

To prevent problems with the GI tract, when a mare gets close to foaling she ideally should be on soft, laxative feeds. Then her manure is softer and it is easier for her to pass bowel movements when she is sore from foaling.

“Some breeding farms routinely administer mineral oil to mares after foaling, to help make sure they don’t become constipated. Putting mares on a mash for a few days before and after foaling is often done, and is the easiest. Many mares foal without any complications but there is still a lot of pain involved after foaling, and a mare may be reluctant to pass manure if it’s firm and causes her more pain when defecating. She may also be reluctant to urinate because it

burns. We have to deal with these situations case by case,” says Tibary. It’s a good idea to put mares on mash when they get close to foaling, and to have something laxative in their diet (like alfalfa) if they are not on green pasture. “Also make sure they are drinking enough, after foaling. Observe them to make sure they are eating and drinking. “Don’t underestimate the importance of that first examination of the mare and new foal within 12 to 18 hours, even if everything seemed to go fine,” he says.

Mare owners need to realize that some problems are not very common, but do happen occasionally. “This is the reason every mare that foals needs to be looked at afterward, to pick up on some of those situations. Even if it’s not life-endangering, it may still be a problem for the mare’s future fertility,” he says. You may be able to treat or correct something now, and prevent problems later. And some situations may or may not be correctable. You may have to make the hard decision about putting down the mare, and end up with an orphan foal. ■

(above) decomposed placenta retained 24 hours

(below) retained placenta