Postpartum Complications in the Mare

If your mare experiences complications following foaling, it's important to note when they arise, said Walter Zent, DVM, a veterinarian at Hagyard Equine Medical Institute in Lexington, Ky., in his presentation at the 2006 Hagyard Bluegrass Equine Reproduction Symposium, which was held Oct. 18-21. Zent said veterinarians can help differentiate between similar conditions based not only on the clinical signs that the mare is exhibiting, but also how much time has passed between foaling until these signs appear.

Post-foaling complications usually present themselves in the first 24 hours, according to Zent. However, there are some conditions that take longer to develop and might not become evident until some time after foaling. In the first 24 hours post-foaling, you should be ready for the following complications: retained placentas, uterine artery hemorrhages, ruptured bowels (which according to Zent, "symptoms can appear quite suddenly"), intrauterine hemorrhages, uterine ruptures, rectal vaginal lacerations, and bowel displacements.

Retained placenta is the most common postpartum complication of mares, said Zent. A placenta is considered to be retained if it has not passed within three hours after birth. Many times this condition can be easily diagnosed because the placenta is partially expelled. However, in some instances the placenta might tear, leaving a piece in the uterus (typically this is the placenta portion from the non-pregnant uterine horn or a tip of the non-pregnant horn). This is why it is very important to examine an expelled placenta to make sure it is complete. A piece that remains in the uterus can cause the mare to become ill. Zent said signs of a retained placenta might take 18 hours or longer to develop.

Uterine artery rupture can occur anytime from a few days before the mare gives birth until a few days afterward, and it is the most common cause of death in older foaling mares. According to Zent, this condition most often appears during or in the few hours following parturition. He also says that the most common site of rupture is the right middle uterine artery, but that rupture of the iliac (pelvic) and ovarian arteries have also been reported. Artery rupture has also been observed more often in mares that have had multiple foals and that are over 14 years old. Zent said he has seen cases in much younger mares, but not as frequently.

From 24-48 hours post foaling, Zent said the following conditions can be seen: retained placentas, post-foaling metritis (inflammation of the uterus, with or without a retained placenta), uterine hemorrhages, uterine tears, prolapsed rectums, bowel displacements, and impactions.

In the timeframe of 48-72 hours after a rectal prolapse at foaling, veterinarians should expect to see retained placentas, metritis, uterine hemorrhages, bowel displacements, uterine tears, gastrointestinal impactions, and prolapsed rectums.

Zent pointed out that some conditions almost always occur at a relatively specific time after foaling, but he agreed that others might occur over a wide range of time. He said he hopes that his suggested timeframes will aid veterinarians in the field in making a proper diagnosis.

About the Author

Rachael C. Turner

Rachael Turner is the former Photo and Newsletter Editor for The Horse. She is an avid event rider. Rachael's main focus is dressage and on training young horses with the proper foundation for success. She is also a member of the United States Dressage Federation and the United States Equestrian Federation. Her website is

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