Streptococcus ovis associated abortion in an Icelandic mare.

This research article explores a case of abortion in a pregnant mare due to an infection of Streptococcus ovis, a bacteria typically associated with disease in sheep, suggesting that it was the first reported case of its kind.

Background and Overview

• The study begins by acknowledging the role of Streptococci, a type of bacteria, in causing abortions in mares. Specifically, bacteria like Streptococcus ovis often infect the uterus and cause pregnancy issues in mares. However, this bacterium is primarily known to cause inflammation in sheep and hasn’t been reported to cause any diseases in horses before this case.
• The infection usually happens when bacteria from the mucous lining of the mare’s lower genital tract make their way up to the uterus.

Case Study

• In the discussed case, an 8-month-old equine fetus’s lung in mono-culture (a culture of a single form of microorganism) was found to be infected by S. ovis. The infection led to acute suppurative bronchopneumonia (a severe form of pneumonia), umbilical cord cellulitis (an infection of the skin and tissues around the umbilical cord) and placentitis (inflammation of the placenta) in the cervical region of the allantochorion (the membrane formed during pregnancy).
• The mare had been living in a pasture along with sheep and was impregnated there.

Possible Cause of the Infection

• The report suggests that the contamination could have occurred a week prior to the abortion when an unknowing veterinarian inserted a double-guarded uterine swab into the mare’s cervical canal.
• This procedure probably damaged the cervical mucus plug (a protective barrier that prevents bacteria from ascending into the uterus), allowing the S. ovis bacteria to pass through the cervical canal and colonize the placenta.
• This unexpected incident highlights the cross-species potential of the Streptococcus ovis bacteria and also underscores the need for careful handling of pregnant mares.