Whether it happens in the middle of the night or on a brisk spring morning, the birth of a foal is usually an exciting, joyous experience, as the owner imagines the star that his foal will become.

But sometimes, the celebrations may be on hold, as the mare may experience problems. Jennifer Davis, DVM, PhD, (clinical assistant professor, equine medicine and clinical pharmacology, North Carolina State University) sees a lot of post-foaling problems at the NCSU animal hospital.

Retained placenta is one of the most common complications. “If the placenta is retained as long as three hours [the mare], needs to be treated. If it’s retained more than three hours, there is the possibility the mare could start absorbing bacteria and toxins from the uterus, become systemically ill, and show signs of endotoxemia, which can lead to shock and laminitis,” said Davis.

“The membranes stay in there and rot; the cervix closes down, and the mare can’t get rid of the membranes,” said Bonnie Barr, VMD, Rood and Riddle Veterinary Hospital in Lexington, Ky. “Always closely monitor the mare, to make sure she is eating and feeling good, not dull and depressed. Take her temperature a couple times a day, to know if it starts to go up.”

Retained placenta should be treated aggressively with the anti-inflammatory agent Banamine and antibiotics. “We may attempt to get the placenta out, but that can be difficult if it’s adhered tightly. Mare owners should not pull on the placenta; if they break off the part that’s visible, it is harder to remove the remaining internalized tissue. Usually we weight down the external tissue. We’ll put a wrap on it, which will get wet and heavy, and provide gentle, steady tension on the placenta to help it come out,” explained Davis.

A veterinarian might also try to distend the placenta with fluids. This can often break the seal between the placenta and the uterus, providing the placenta is intact and the fluid isn’t just going directly into the uterus. “Other than this, it’s usually just a matter of patience and gently teasing it out over several days–but this is not something we advise mare owners to do,” Davis said. “If part of it breaks loose and leaves a piece in the uterus, this can be a serious situation.”

When a placenta comes out, it needs to be examined by a veterinarian to make sure that it’s intact, with no piece(s) left inside. “Even if the whole placenta comes out, the mare may have endometritis or metritis—infection in the uterus that needs to be treated with antibiotics and flushing,” said Davis.

Veterinarians may also administer preventative medications to avoid side effects such as founder. “We try to get on top of this as quickly as we can,” said Davis. “We’ll keep her in a heavily bedded stall and put wraps on her feet. Sometimes we ice the feet, or give medications to help maintain blood flow to the feet. We make sure there is enough padding to keep them comfortable and not bearing too much weight on the toes.”

In addition, these mares may need IV fluid therapy, particularly if they show signs of endotoxemia. “It can be fairly difficult to treat them, and sometimes they need hospitalization–especially if the placenta hasn’t passed within 24 hours of foaling,” she added.

Retained placenta is more common after a difficult birth, which can also imply that there might be something wrong with the foal, so it’s also a good idea to keep a close eye on the foal—in case there are more problems than you realize. Any time a mare foals, the placenta should be examined thoroughly, to make sure there are no areas of infection, thickening or any other abnormality. You can put the placenta in a plastic bag and put it in your refrigerator until the veterinarian arrives, suggested Davis.

Uterine Tears

On occasion the uterine lining or wall may tear, especially if it’s a difficult birth and the foal had to be pulled or is large.

“A tear can be difficult to diagnose. Uterine fluid starts to leak through the tear into the abdomen. You don’t see anything unusual at first; the abdomen is large and it may take awhile for the fluid leaking in there to set up infection and for the mare to show signs. She’ll get a fever and go off feed and show signs of colic and depression. It can be extremely serious; there may be fibrin forming in the abdomen, which can lead to adhesions between the intestines, and the mare becomes prone to chronic colic,” said Davis.

Tears may also be found in the vulva, cervix, or uterus itself. “If the mare has a hole in the uterus, this can lead to peritonitis,” said Barr. “The mare should be closely monitored for several days after foaling. Even with a hole in the uterus or something going wrong in the gastrointestinal tract, it may take 24 to 36 hours before the mare gets really sick.”

Overwhelming sepsis can be life threatening. “There’s no real way to sew up the uterine tear except to take the mare into surgery. Even this is not always successful, since the tear may be difficult to access. But sometimes you can treat the infection and keep it under control while the uterus heals itself. Thus it’s much better if it’s a small tear and you catch it early,” Davis said.

Sometimes drains are needed in the abdomen, to flush the abdomen from the outside. “Anytime there’s a dystocia [difficult birth] or the baby has to be pulled, it’s wise to have your veterinarian take a feel of the uterus after the foal is delivered, to see if everything is all right. This can be difficult to determine, however, because most people’s arms aren’t long enough to feel to the end of the horn that the baby was in. Once the uterus starts to come back to normal size, it folds back in onto itself, so it can be very difficult to diagnose these tears after the fact,” Davis said.

Working at a referral hospital, Davis said they don’t often get to check the mare until there is actually an infection in the abdomen. “Then we do an abdominocentesis [sticking a needle into the abdomen and sampling the abdominal fluid] and find increased white cells and protein and sometimes red cells. We can also insert an endoscope into the uterus and look around. The tear can be hidden in one of the folds, but the endoscope is a little more successful, many times, than trying to get your arm far enough in there,” she said.

If the mare does survive, the torn area may scar and prevent her from carrying pregnancies in that horn in the future, if it’s a big enough tear. “If she is bred again, you are basically cutting your chances in half, to have her become pregnant,” said Davis. “Most of the time, what we are worrying about is just saving the mare. If she survives, then we tell the owner that she may not be the best broodmare prospect. Most of our clients just want the mare saved, so we do our best.”

Staving Off Colic

There are a couple specific types of colic related to pregnancy, and one of these is colon displacement or torsions. The abdomen has been filled with a foal, and when it’s gone, there is suddenly a lot of empty space. The colon can become filled with gas and then get out of place or turn over on itself.

“Occasionally, displacements can be treated medically, but colon torsions are surgical cases and are fairly difficult to treat,” Davis said. “If the colon starts to lose blood supply [the twisting shuts off blood vessels] it can become very compromised and leak toxins and bacteria into the bloodstream. It is very difficult to actually remove all of the colon. It’s a very expensive process, and the animal tends to have more complications than if we remove a piece of small intestine, because they lose the ability to absorb water.”

The colon is where the remainder of any fluid in the digestive tract is reabsorbed before the feces are formed. With the colon removed, the horse may have problems with chronic diarrhea.

“Fortunately, torsions are a little less common than actual displacements, after foaling. Displacements tend to do very well. Most of them are surgical, but some can be treated medically–with supportive care, lots of fluids, and a little pain relief. If the colon is not displaced too far forward, and we can get the mare moving and restore some motility, things may straighten out and she will be able to start moving things through again,” said Davis.

If there is a retained placenta or fluid in the uterus that needs to be flushed out, the mare is often put on oxytocin after foaling. The oxytocin therapy can make a mare act a little colicky, just because it stimulates the uterus to contract more.

“These contractions can be painful, and people think the colic is due to the oxytocin when it may be due to an actual intestinal problem. This can mask the picture. If the mare gets colicky we usually stop the oxytocin therapy for a couple of hours to see if the signs of colic resolve. If colic persists, the mare needs to be treated,” said Davis.

Another type of colic involves bruising of the intestine. The foal in the uterus sits on a piece of intestine for a while, and this pressure can cause bruising and a little hemorrhage in its wall. “Any time that happens, this can stop the motility of that piece of intestine. The one we worry about the most is the cecum. It is located on the right side of the abdomen so it usually only happens with right horn pregnancies,” she said.

If the bottom part of the cecum gets damaged, food can start building up, filling the cecum. “The mare doesn’t show signs of colic until it gets very distended. She looks fairly normal, but has this huge impaction in the cecum, with gas or fluid building up in it,” said Davis.

“Cecums can get very large, and you may not notice any signs of problems until they are about to rupture. If fluid therapy isn’t helping and painkillers aren’t controlling the pain, the mare sometimes needs to go to surgery to have the impaction removed,” she said.

A successful outcome, however, depends on how much of the cecum was compromised during pregnancy. This will determine whether or not it will start moving again.

“This can be a life-threatening problem for the mare after foaling. Usually the first clinical signs are decrease in fecal output–less than five piles per day–and what the mare passes is often smaller than normal,” she said.

Sometimes the manure is firm, but in some cases it can actually get too soft because not much can come through the impaired, partially blocked cecum except liquid. The mare may have diarrhea–the fluid that can move across the top of the impaction.

“With any horse we have here in the hospital, we monitor how many fecal piles are produced every day. If it gets below five piles, we do a rectal exam and possibly tube the mare with oil to see if that comes through–although they can pass oil and still be blocked in the cecum,” she said. “Sometimes we get fooled because a mare is passing a normal number of piles, but when you actually examine the piles you find they are smaller, or they are too dry or too loose. If things don’t seem quite right, you should have your veterinarian check the mare.”

Identifying Hemorrhages

Though it’s more common in older mares that have had many foals, uterine artery ruptures can occur in any mare after foaling, and there’s generally no external evidence of bleeding.

“The mare may just act colicky, but if you look at her membranes, they will be pale,” said Barr. “Heart rate may be high. The mare may be sweating and very anxious, and pawing.”

Other arteries, like the internal pudendal and caudal uterine artery, bleed out the vagina, rather than into the abdominal cavity. “Either one of these situations is life-threatening. A lot of them present with signs of colic, rather than hemorrhage, but we can usually be suspicious, based on simple blood tests. A PCV measurement will tell us if the mare is losing red cells and protein somewhere–most likely into the abdomen,” Davis said.

Then they can do an abdominocentesis. “It’s not abnormal for a mare to have a slightly red tinge to the abdominal fluid after foaling, particularly if it was a difficult birth. So when we get that sample, if we are worried about a hemorrhage, we run the same test on it that we do on the blood, to look at the percent of red cells and protein. If it’s starting to approach what normal blood would be, we know there is blood in the abdomen,” explained Davis.

“Sometimes the veterinarian can actually palpate the hematoma [blood clot], particularly if it’s contained in the broad ligament that supports the uterus. It feels like a hump. Anytime you feel that, you want to come right back out, very carefully, and try not to disturb the clot,” she said.

If it’s a ruptured uterine artery, usually the only effective treatment is to put the mare in a stall and keep her very, very quiet, and let nature take its course. “You want to keep her blood pressure low. Sometimes we’ll give her acepromazine because this can decrease blood pressure as well as keep the mare calm and quiet in the stall, though this may exacerbate signs of hypovolemic shock. If it’s a rapid blood loss and the PCV gets really low, the mare may need blood transfusions, but doing that may increase the blood pressure, as well. It’s a tricky balancing act. Sometimes the mare needs oxygen therapy. We’ll also put her on antibiotics, because having all that blood in the abdomen provides a great medium for bacteria to grow,” said Davis.

Walter Zent, DVM, Hagyard, Davidson and McGee, Lexington, Ky., recalled a time when hemorrhaging mares weren’t treated aggressively because of fear of raising the blood pressure. “Now we use IV fluid replacement if they need it–plasma or whole blood. We also treat them for shock,” he said. “I think we save a few more, though we certainly don’t save them all.”

On more rare occasions a mare may rupture other arteries and actually bleed out the back. “If bleeding is into a cavity like the abdomen, eventually it fills up and starts causing back pressure [there’s no room for any more blood]. This puts pressure on the bleeding artery and helps stop the bleeding. But if a mare is bleeding externally [from the vagina and vulva] there is no good way to stop it. It is fast and dramatic, and usually fatal. Fortunately, this is a lot more rare than the other artery ruptures,” Davis said.

Tending To Trauma
Vaginal trauma can also be a problem post-foaling, with recto-vaginal tears, if the foal puts a foot through the birth canal on his way out–creating a hole between the vagina and the rectum. “These tears are usually not life-threatening, but if there is a big enough hole, feces from the rectum can gain entry to the vaginal vault and increase the risk of infection in the uterus, particularly right after foaling when the cervix is still dilated. Usually we don’t repair these tears right away,” Davis said.

Instead, they wait for swelling to decrease, and for a nice healthy bed of granulation tissue as the wound starts to heal. “But this is certainly something your veterinarian needs to be on top of. We usually put these mares on stool softeners to make sure they continue to pass manure and don’t become impacted, since the act of passing manure is very painful. We try to keep them on soft feed like Equine Senior with some water mixed in, and green grass (if there is any). We often tube them with mineral oil or other stool softeners to make the manure easier to pass.”

Green grass is ideal, but it can be hard to keep enough weight on a lactating mare without feeding her some additional forage such as hay, which can often cause them to impact.

“Usually, even if you sew up the tear right away, it tends to break down quickly and you have to go back in awhile later and sew it again. These can be difficult surgeries, simply because it is difficult to access the tear,” said Davis.

She sees a lot of vaginal bruising where hematomas form in the wall and there is swelling. “Usually these are not life threatening and do not affect long-term fertility but can be very painful. The mare may require some pain-killing drugs,” said Davis.

Some mares tear at the vulva, particularly if it’s a first foal and the foal is a little large. “Usually we just sew these up. As long as it doesn’t communicate with the rectum, those can be done within a couple of days after foaling [after initial swelling subsides],” she said.

If the cervix is torn, that can be difficult to repair. “Most veterinarians don’t try to sew these unless it’s a full thickness tear; in that case it would communicate with the abdomen and be similar to a uterine tear. If it’s just partial thickness tearing, we’ll often let it heal on its own. It may create scarring, however, and then the cervix can’t close properly; the mare may be infertile, with chronic infection in the uterus and chronic drainage. At least with cervical tears they are easy to palpate and can be checked right after foaling when the cervix is still dilated. This is something your vet would look at during a post-foaling exam, the first visit after foaling,” said Davis.

Another complication—vaginal or uterine prolapse—occurs when the mare strains so much during the birthing process that part of the vagina or uterus protrudes through the vaginal opening. If it is just the vagina, medications can be given to stop the straining, the tissue can be replaced, and a Caslick’s repair performed to help keep it in place.

If it is part of the uterus prolapsing, this is much more difficult to replace and tends to recur. If a sufficient amount of uterus is prolapsed, it can cause tension on the broad ligament and uterine arteries, which may then rupture and cause severe hemorrhaging as described above. The externalized tissue is also highly prone to infection and contamination from the environment.

“Most commonly it would be the uterus prolapsing, but sometimes the bladder may come out too,” said Barr. “Basically, if you see anything abnormal after the foal is born and after the placenta is passed, this is definitely an emergency.”