Laparoscopic Ovariectomy Diminishes Estrus-Associated Behavioral Problems in Mares

Synthetic progestins, including altrenogest, are employed to modify undesirable estrus-related behavior or poor performance in mares. Bilateral laparoscopic ovariectomy (BLO) is another means of management. Our objective was to compare the perceived improvement in mares with estrus-related problems administered altrenogest to BLO. Owners of mares with estrus-related problem(s) that had undergone BLO after altrenogest treatment completed a telephone survey. They rated the behavioral or performance improvements with altrenogest and after BLO on a Likert scale (1 = no response; 5 = complete resolution). They also compared improvement with altrenogest and following BLO (1 = better response with altrenogest; 2 = comparable responses; 3 = better response with BLO). Likert scores for the two treatments were compared using the Wilcoxon signed rank test. The association between altrenogest and BLO scores was compared using Spearman rank-order correlation. Owners or trainers identified a variety of estrus-related problems in 20 mares meeting the inclusion criteria. Median scores for BLO were significantly higher than those for altrenogest (P = .008). The association of the perceived response to altrenogest and BLO was positive but relatively weak (ρ = 0.288). In a substantial proportion of mares with estrus-related problems, a salutary response to altrenogest was associated with a favorable response to BLO; however, some mares showing limited improvement with the progestagen still responded favorably to BLO. In this series, BLO was perceived by owners or trainers to be at least as effective as altrenogest administration as a means of diminishing a number of estrus-related behavioral and performance problems.