Theriogenology question of the month. Scoliosis.

This study discusses the diagnostic process and treatment of a 6-year-old Standardbred mare suffering from prolonged gestation and dystocia. Despite an initially uneventful pregnancy, complications arose during parturition, primarily due to problems with fetal posturing. Upon veterinary examination, the fetus was found to be nonviable.

Case Presentation

• The subject of this study was a multiparous (having given birth more than once) Standardbred mare aged six years, brought to a veterinary medical teaching hospital due to dystocia, or difficult childbirth, that had been ongoing for four hours.
• The mare’s gestation period was described as prolonged, as it had reached 356 days at the time of parturition – longer than an average equine pregnancy, which typically lasts approximately 340-342 days.
• Early in her pregnancy (day 114), the mare was diagnosed with Potomac horse fever, a potentially dangerous equine disease. However, she was successfully treated and the pregnancy reportedly continued without any notable abnormalities.

Medical Examination

• An initial examination at the veterinary hospital showed the mare to be quiet and alert, her heart rate and respiratory rate both appearing normal.
• Abdominal auscultation revealed a decrease in intestinal sounds across all four quadrants of her abdomen, suggesting potential abnormality in her digestive function.
• The mare was then sedated using xylazine hydrochloride and the area around her lumbosacral joint was prepared aseptically for further examination. Morphine was administered epidurally.

Obstetric Examination

• Upon an obstetric examination, the fetus was found to be stuck in the birth canal.
• Despite all four limbs and the nose extending through the dilated cervix into the front of the vagina, no part of the fetus was extending through the vulva.
• The apparent absence of Ferguson’s reflex, which is typically initiated during childbirth to aid in the expulsion of the fetus, suggested uterine exhaustion, likely brought about by the length of time since labor had begun.
• The fetus was found to be unresponsive and thus presumed nonviable. This is a suggestive finding that the fetus had not survived the prolonged and difficult labor.