Efficacy of Oviductal Flushing with PGE2, in Mares, in and Out of the Breeding Season

Reasons for performing study There are limited data surrounding the efficacy of oviductal flushing in restoring fertility in mares with repeated returns to oestrus. Objectives To determine the conception and foaling rates in mares treated by laparoscopic topical application of prostaglandin E2 (PGE2) to the oviduct(s) in mares: i) in the breeding season (January–May), pre-covering; ii) in the breeding season, post covering; and iii) out of the breeding season (June–December). Study design Follow-up study. Methods Analysis of electronic patient records (EPRs) identified 29 mares that underwent oviductal flushing via laparoscopic surgery between 1 January 2008 and 12 October 2014. One mare underwent the procedure twice; once in the breeding season (pre-covering) and once out of the breeding season. Follow-up data were collected via EPRs and from Weatherbys (www.bloodstockreports.co.uk). Results The procedure was used in 27 Thoroughbreds, one Warmblood and one Hanoverian. Mean age at the time of the procedure was 13.1 years (range 6–22 years). Mean duration barren prior to the procedure was 1.9 years (range 49 days–5.6 years). The mean time post flushing to the first positive ultrasound scan was 31 days, with average time post flushing to foaling of 367.6 days. Of the 29 horses, 55.2% (16/29) conceived successfully, with 87.5% of these confirmed to have produced a live foal. In the breeding season, 16 mares were treated; 10 pre-covering, and 6 post covering with conception rates of 60.0% and 83.3%, respectively. Thirteen mares were treated out of the breeding season, with a 35.7% conception rate. Conclusions Oviductal flushing within the breeding season was more successful in this study than flushing performed out of the breeding season. Restoration of fertility in this study was lower than that previously reported and potential reasons for this include limited pre-surgical diagnostic testing, differing prior pathologies or reasons for sub-fertility, and case selection. Ethical animal research: Research ethics committee oversight not currently required by this conference: retrospective study of clinical records. Explicit owner informed consent for inclusion of animals in this study was not stated. Source of funding: C.E. Wylie is funded by the Margaret Giffen Trust. Competing interests: None declared.