Mid- and late-term foal abortions can be both economic and emotional burdens. While not all abortions can be prevented, researchers now believe that veterinarians might be able to determine if some mares are at risk of late-term abortion by conducting a simple blood test.

“The most common cause of mid- to late-term abortions, premature delivery, and neonatal death in the first 24 hours of life involve problems with the placenta,” said Igor F. Canisso, DVM, MSc, Dipl. ACT, ECAR, from the University of Kentucky’s Maxwell H. Gluck Equine Research Center. “Infection of the placenta close to the cervix and vagina (ascending placentitis) is most commonly caused by bacteria such as Streptococcus equi zooepidemicus, which enters the vagina, penetrates the cervix and uterus, causing life-threatening infections. Signs of placentitis in mares include vulvar discharge, “softening” of the cervix, and premature udder development and lactation.

“Early diagnosis of placentitis and prompt and appropriate treatment are paramount for survival of the foal, and ultrasound is the most common tool currently used to diagnose placentitis,” added Marco A. Coutinho da Silva, DVM, MS, PhD, Dipl. ACT, from The Ohio State University’s Department of Veterinary Clinical Sciences, College of Veterinary Medicine.

For years, the veterinary community has viewed placentitis as a “focal” disease, but Canisso and Coutinho da Silva recently learned that placentitis causes an increase in acute phase proteins circulating in the bloodstream, which means the inflammation is not restricted to the uterus