Uterine Torsion in Mare

Background: A review of the factors and diagnostic and therapeutic methods of uterine torsion in mares.
Objectives: To describe the causes of uterine torsion, its symptoms and diagnosis, and methods of non-surgical and surgical correction in mares.
Methods: A review study using published sources on uterine torsion in books and national and international reputable journals.
Results: Uterine torsion most often, but not exclusively, arises in mares during the last trimester of pregnancy and initially presents as colic. Uterine torsion may occur in a clockwise or counterclockwise direction, with clockwise torsion generally thought to be more common. Regardless of which direction the torsion occurs, if it incorporates gastrointestinal structures, the colic will be more severe. Vigorous fetal movements, rolling, and falling of the mare due to elongation of the broad ligament, or stretching of the broad ligament during pregnancy, can predispose the mare to torsion. Affected mares may exhibit signs of colic, including lethargy, anorexia, restlessness, pawing, sweating, and frequent urination. Torsion is diagnosed by rectal palpation, and if necessary, ultrasonography will confirm fetal viability. The torsion should be corrected promptly for the best chance at mare and foal survival. Correction can be undertaken with nonsurgical means or with surgery. If nonsurgical correction is required, the direction of rotation must be properly identified. If this cannot be done with certainty, nonsurgical correction should not be undertaken. Nonsurgical methods of correction are discussed in this article including manual rotation of the uterus in the standing mare from vaginal canal and rolling the mare’s body around uterus. Surgical options for resolving uterine torsion include standing or recumbent flank laparotomy, and ventral midline celiotomy. The choice of procedure depends on the stage of gestation, concurrent gastrointestinal involvement, uterine rupture, potential for uterine wall compromise, the degree of rotation, fetal viability, severity of pain, surgeon’s preference and client financial constraints. The prognosis for future fertility is usually good.
Conclusions: This article discusses the symptoms and diagnostic methods of uterine torsion in mares and discusses its treatment methods.