A Case Report of Uterine Body Constriction Precluding Normal Parturition Leading to Dystocia in a Mare

SIMPLE SUMMARY: The presentation of equine dystocias to a referral clinic varies significantly. This case report describes the clinical and postmortem findings of a case of uterine body constriction in a late gestation mare that precluded normal vaginal delivery, ultimately resulting in fetal mortality with humane euthanasia of the mare. Gross examination revealed a circumferential, tan, fibrous band at the base of the uterine body that constricted the uterus and was adhered to the left and right ovaries, supporting the diagnosis of a uterine body constriction. ABSTRACT: A 13-year-old multiparous Quarter Horse mare was presented to the Michigan State University’s, Large Animal Emergency service for dystocia. Clinical evaluation revealed a minimally dilated cervix on vaginal examination, with a palpable deceased fetus. Postmortem evaluation following owner-elected humane euthanasia revealed a circumferential, tan, fibrous band at the base of the uterine body that constricted the uterus and was adhered to the left and right ovaries. A routine histologic section of the incarcerating cord attached to the ovary consisted predominately of dense fibrous connective tissue, large blood vessels, and a central oviduct suggestive of a rent in the broad ligament. To the authors’ knowledge, this is the first case report to describe uterine body constriction that precluded vaginal delivery of a fetus in a late gestation mare.