Causes of abortion, stillbirth, and perinatal death in horses: 3,527 cases (1986-1991).

The research article examines the causes of abortion, stillbirth and perinatal death in horses over a five-year period. The study investigates the pathology of 3,527 recorded cases, aiming to identify the common factors leading to these issues.

Methodology

• The research involved reviewing pathology case records from aborted fetuses, stillborn foals, and foals that died within 24 hours of birth. It also included 13 placentas from mares whose foals were weak or unwell at birth.
• The key objective was to ascertain the causes of abortion, death, or illness amongst foals.

Findings

• Fetoplacental infection – caused by bacteria, equine herpes virus, fungi, or placentitis – was identified as the most common cause of issues observed. An etiological agent couldn’t be defined in several cases of placentitis.
• Complications during birth were the second most prevalent cause of death. Such complications included neonatal asphyxia, dystocia or trauma; these were diagnosed in 19% of the cases.
• Other diagnoses established as common causes included placental edema, premature separation of placenta, development of twins, contracted foal syndrome, other congenital anomalies, and umbilical cord abnormalities.

Less Common Causes

• The study also identified several less common conditions that could potentially lead to abortions, stillbirth, or perinatal death. These included placental villous atrophy, fetal diarrhea syndrome, body pregnancy, neoplasms, and other miscellaneous conditions.
• In 16% of the cases investigated, a conclusive diagnosis couldn’t be established.

Infections

• The study identified leptospirosis as a significant cause of bacterial abortion in mares. It also noted that infection by a nocardioform actinomycete was an essential cause of chronic placentitis.