Equine Placentitis

Placentitis is an infection of the mare’s placenta, usually occurring within the last 3-4 months of gestation. It can be an extremely devastating condition for the owner both emotionally and economically, as it can be a difficult condition to treat and still may end with a nonviable fetus. The earlier this condition is identified, the better the chance is of treatment working and resulting in a healthy baby.

90% of cases of placentitis result from an ascending infection through the mare’s vagina and migrating through the cervix. This bacterial contamination results in thickened fetal membranes and premature separation of the placenta from the mare’s endometrium. All of this results in decreased oxygen and nutrients to the growing fetus. Also during this process, white blood cells are responding to the infection and producing both pus and pro-inflammatory mediators which may result in abortion of the foal. Common signs of placentitis include premature udder development or lactation and sometimes vulvar discharge. In addition, often the thickened placenta can be seen on ultrasound along with separation of the membranes. Hormonal blood tests can be helpful in cases where it is unclear if placentitis is occurring.

Treatment of placentitis is multifold and includes appropriate antibiotics to treat the infection, along with medications to decrease the inflammatory response. Also, typically these mares are put on Regumate to help block the pro-inflammatory mediators and try to stop uterine contractions from occurring.   Also other drugs may be added to the regimen to help the blood flow to the foal hoping to improve viability.

If a mare delivers a foal prematurely, the fetal membranes need to be examined closely for any signs of thickening or other signs of infection. Also if placentitis is suspected, the veterinarian needs to be involved immediately as even though some of the foals can appear normal at birth, they will often decline rapidly. The sooner treatment can be instituted, the better the chance of a healthy foal.

Also if a mare does have placentitis, after foaling a culture of the uterus should be done and subsequent treatment based on the culture otherwise their ability to get pregnant and maintain a pregnancy may be hampered.

There is one other type of placentitis (not from a bacterial infection) that we see commonly in our area called fescue toxicosis which results from mares eating large amounts of endophyte infested tall fescue. The endophyte in tall fescue produces alkaloids that can affect multiple critical hormones in the mare that have effects throughout the body and can cause a number of issues including a thickened placenta, abortion, retained placenta, prolonged gestation and a lack of milk production by the mare once the foal is born. Prevention is the best treatment, so the recommendation is not to graze broodmares on fescue in the third trimester of their pregnancy. There are oral medications including domperidone that can be helpful in treating the agalactia (not producing milk) part of this form of placentitis, however again often these foals are not as healthy as normal foals due to them not absorbing as much oxygen and nutrients while in utero due to the thickened placenta, plus they are not receiving vital nutrients and antibodies (colostrum) from the mare if she is not producing milk.

If you have any questions about your broodmare’s risk for this condition or see any clinical signs described in this article, please call your veterinarian immediately.

Spring Surprise!

On an early morning in March, Susan Drillock went out to the barn, as she does every morning, to feed her horses. Included in her herd were Bandit and Bonnie, a pair of miniatures adopted from a neighbor. They had lived together for years with little interaction with people; although Bandit was halter broke, Bonnie was basically unhandled. In the months they had lived at the Drillocks, progress had been made to tame Bonnie, but it was a slow process. Susan readied their feed and water, opened their door, and gasped as she saw in the stall, not 2 minis, but 3, the third tiny and new, barely 25 pounds.

Because no one knew that Bonnie was pregnant, though, pre-natal precautions such as vaccinations and removal of fescue from her diet had not been taken. Susan called Dr. Jennifer LaPlume, who confirmed that the mare was not making milk and had not made colostrum, a situation which left her foal dehydrated, depleted of energy, and with nearly no immune defenses. The foal was getting steadily weaker as the day went on. Even though the foal was a surprise, and even though her parents were basically rescues, the Drillocks made a commitment to the foal, and brought her to Blue Ridge Equine Clinic for intensive care.

The foal was managed and treated in our hospital, under my supervision. She was placed on powerful antibiotics, and was given plasma for immune support , intravenous fluids, and dextrose for energy. A feeding tube was placed, as the foal was too weak to drink on her own. She had nursing care around the clock. Bonnie was given domperidone to stimulate milk production. Within days, the filly was vigorous and Bonnie was producing milk. They had never been totally separated from one another, and Bonnie was an excellent mom, so they were soon back together as if nothing had happened.

Days later, Bandit was gelded to prevent further surprises. Everyone is reportedly doing well. The filly is named Gigi Riser Swishy Tail, after Susan’s beloved Aunt Gigi, with whom she shares a birthday. Congratulations to the Drillocks on this beautiful foal; your horses are lucky to have you!

Fescue Toxicosis In Broodmares

Much of the pasture in Virginia is tall fescue. While this hardy grass is a high quality nutrient source for most horses, it is often infected with an endophytic fungus named Acremonium coenephialum that is toxic to pregnant mares. The fungus produces damaging alkaloids such as ergovaline.

Some results of fescue toxicosis are:

  • Late term abortions (death of the fetus), usually in the last 2 months of gestation
  • Dystocia (difficult foaling)
  • Premature placental separation (red bag delivery) – This is a veterinary emergency and results in lack of oxygen during birth.
  • Prolonged gestation in mares (up to 13 months)
  • Decreased milk production
  • Failure of passive transfer (IgG) in the foal from lack of colostrum production in the mare
  • Retained placenta
  • Decreased growth rates in young horses if forage is not supplemented with grain

An ounce of prevention is worth a pound of cure! What can you do to prevent fescue toxicity?

  • Have your pasture and hay tested to determine the level of infection
  • Mow fields prior to the development of seed heads, which contain the highest levels of toxins in the plant
  • Remove broodmares from fescue pastures 30 days prior to breeding and a minimum of 60 to 90 days prior to foaling
  • Make sure hay does not contain endophyte infected fescue either
  • Keep accurate records of breeding and anticipated foaling dates
  • Monitor the mare closely during late pregnancy
  • Contact your veterinarian if impending signs of birth, including udder development, relaxation of vulva, and muscles around the tailhead fail to develop within the expected timeframe or if these signs develop prematurely
  • Attend the birth. If mare fails to show signs of normal birth progression, contact your veterinarian immediately!
  • Keep mares and foals off fescue until after weaning to prevent poor milk production


The Challenge Of Colic Surgery On Pregnant Mares

Colic emergencies in late term mares pose an exceptional challenge to veterinarians and owners, as the diagnostic information usually obtained on a rectal examination and abdominal ultrasound are extremely limited due to the large size of the fetus. Furthermore, abdominal surgery carries significant risks to the mare and foal both at the time of surgery and then at foaling. Anesthesia poses risks to both mare and foal, and the foaling puts tremendous stress on the still healing abdominal incision.

These were the concerns present when Kim Schmidt brought her mare,  O’Susannah, into the clinic on March 28 for colic. The 15y old Holsteiner mare was due on April 2 and was already starting to bag up. The mare had been treated at the farm by Keswick Equine Clinic for 36 hours but Susie continued to be persistently painful and had passed no manure. On admission to BREC, we had some concern that the mare had a colon displacement but we could not definitively rule out a simple impaction. After 48 hours of aggressive fluid therapy, there was no improvement and we felt it was time to take a look.  At surgery, a right dorsal displacement was identified. This proved a difficult one to correct due to the large fetus sitting on top of the colon, but ultimately we were successful. The mare did very well under anesthesia and recovered nicely. She was immediately comfortable after the procedure and made steady progress over the next few days. Abdominal ultrasound on April 1 revealed a normal heart rate for the fetus.  Next, it was just a question of getting through delivery. Susannah post colic surgery

The colic and surgery seemed to set back the clock on the progress toward foaling. Susie’s bag had disappeared and when she returned to the farm on April 4, foaling did not seem imminent. This was actually a good thing as it bought more time for the healing of her abdominal incision. Soon her udder was enlarging again and our excitement, along with a tinge of anxiety, began to build. At 9 PM on April 12 (almost 2 weeks from the surgery), Susannah was in labor.   Although there were a few complications on delivery, namely mecomium in the amniotic fluid, partial early separation of placenta (red bag delivery), and an enlarged umbilical cord, Kim and her husband were able to assist the mare in a successful delivery and O’Susannah delivered a big vigorous colt and her abdominal incision was unfazed by pressure.

Both mare and foal have continued to do well and we thank Ms. Schmidt for the pictures and for allowing us to tell this story. Over the years we have had a number of colic surgeries on late term mares and, to date, all mares have recovered and had healthy foals.

Kim Schmidt, a Grand Prix Dressage rider, is the breeder, owner, trainer of O”Susannah and lives with her husband on their farm, Grayson Farm, near Scottsville, Va. where she runs a breeding, boarding, training business: https://www.graysonfarm.net

Kim adds:  O’Susannah is a home bred who has had successful careers in Eventing at the 2 star level as well as Jumpers, Fox Hunting and Dressage at the FEI Intermediare 1 level. She has also had three foals. She will return to the Dressage ring with Kim after the weaning of “Dino” registered name: “Don Dinero”. (Translated: “Mr Money”, because it took alot of money to get him here)!

All the best to Kim, Susannah and Dino!




Foaling Season Is Almost Here!

Foaling season is right around the corner. Some of us have already seen our first 2014 foal.  Please remember to take your mares off fescue in their third trimester and also to get their prefoaling shots done 1 month before foaling. Also, mares that have been caslicked will need to opened up several weeks before their due date. Begin preparing a clean dry stall for your mare and getting her used to the routine of coming in at night beginning 1 month before foaling.  It’s good practice to check her as often as possible (at least twice daily), especially in cold weather.  Mares can surprise you with early deliveries, and quick response may be required to keep new foals warm.

Remember that it is imperative the foal get adequate colostrum within the first twelve hours after birth. This means the foal must be nursing well and the mare must be producing good quality milk with adequate colostrum in it. The best way to determine this is via a blood test on the foal 12 hours after birth. This test measures the amount of antibodies that the foal has absorbed from the mare’s milk. If this number is not adequate, there are several ways to improve this number, improving your chances of having a happy healthy foal.

As always, call your veterinarian with any questions or concerns.