Approximately 20,000 mares are bred in Kentucky each year, which means that it is literally “raining foals” in the spring, as long as things go as planned. Unfortunately, late-term abortions and even abortion storms can occur, resulting in massive economic and emotional mayhem.

The most common cause of late-term abortion is placentitis—an inflammation of the placenta. Frequently, placentitis is caused by bacteria found in the environment ascending though the vagina and cervix, subsequently spreading from the part of the placenta referred to as the cervical star. Signs of this “ascending placentitis” are early mammary development and lactation and eventually vulvar discharge.

Another, but less common, type of placentitis is called nocardioform placentitis.

"Nocardioform placentitis involves specific types of filamentous, branching bacteria, called actinomycetes, and the disease is very different from an ascending placentitis in that only the interface between the placenta and the uterine lining is affected and only the lower (ventral) part of the uterine body and the base of the uterine horn is affected,” explained Mats H.T. Troedsson, DVM, PhD, Dipl. ACT, ECAR, the director of the Gluck Equine Research Center at the University of Kentucky. "In the case of an ascending placentitis, the lesions are found around the cervical star and bacteria invade the placenta, fetal fluids and infect the foal