Fertility and complications after fetotomy in 20 brood mares (2001-2006).

Objective: To report fertility (foals conceived, live foal births) of mares after partial fetotomy to resolve dystocia and complications associated with fetotomy.

Study Design: Retrospective study.

Animals: Horses (n=20).

Methods: Medical records (2001-2006) of mares that had partial fetotomy (1-3 cuts) for dystocia were reviewed. Complications and subsequent fertility were obtained by interview and live foal data were recorded by the Jockey Club. Postfetotomy conception and live foals produced over 21 breeding seasons (defined as years each mare was bred regardless of conception) were recorded.

Results: Twenty mares were identified. Bilateral carpal flexion alone (3 mares) or in combination with another deformity (7 mares) was the most common presentation for dystocia. From 2001 to 2006, there were 24 breeding seasons for which 20 mares conceived (83%). Eighteen mares conceived before 2006 and all produced live foals. Three mares were bred in 2006; 2 became pregnant, 1 was electively aborted, and 1 is pregnant. Eight of 19 (42%) mares had retained placenta, which were expelled within 24 hours after medical therapy.

Conclusion: Partial fetotomy performed with 1-3 cuts does not impede a successful reproductive future.

Clinical Relevance: In selected equine dystocia cases, partial fetotomy should be given primary consideration when the foal is dead and vaginal delivery cannot be readily achieved. Fetotomy should not adversely affect the future fertility of the mare.