b'VETERINARY REPRODUCTIVE SPONSORED BY MEDICINE AT THE CORNELL EQUINE PARKCan Ovariectomies Be Justified onbehavior, but he said its most likely due toMARE FOALING SERVICEBehavioral Grounds? estrogen from the adrenal gland.When mares behave badly, we can beIf the goal is to change aggressive quick to blame their hormones. And, typi- behavior, an ovariectomy might be more cally, we want a quick fix. Could removingsuccessful, he noted. Its also more likely their ovaries be a viable solution? Jamesto be curative if the cause is ovarian pain.Crabtree, BVM&S, CertEM, MRCVS, di- Crabtree listed alternative therapies for rector of Equine Reproductive Services, incontrolling undesirable behavior in mares:the U.K., aimed to answer this question.Progestogen supplements, such as Undesirable behaviors clients often re- altrenogest (e.g., Regu-Mate).port in their mares, said Crabtree, include Prolonging the lifespan of the corpus overt reproductive behaviors, aggression,luteum (the structure responsible forThe reproductive medicine specialists and, in most cases, difficulty training orproducing progesterone post-ovulation)at Cornell Universitys Equine an unwillingness to respond to the rider. with coconut oil infusions, the hormone If the veterinarian confirms hormonesoxytocin, intrauterine sterile acrylicHospital offer close monitoring of are to blame, the question then becomes,spheres, or pregnancy termination.your late gesation mare at the Can we justify an ovariectomy? Inducing late diestrus ovulation. Cornell Equine Park, located only To answer this, he found and highlight- Administering a gonadotropin- minutes from the Hospital. ed four important papers from the past 30releasing hormone vaccine or overdose years that shine light on the topic: to suppress the hypothalamic-pituitary- Video surveillance monitoring throughout the mares stay1. I n 1993 Hooper et al. retrospectivelytesticular axis. The vaccine is onlyPre-Foaling:evaluated 23 bilateral ovariectomy casesavailable in Australasia.(both ovaries removed), 16 of whichOverall, he said, such behavior mightDaily physical exams and transrectal/were for behavioral reasons, and foundbe better managed with medical therapyabdominal ultrasound evaluation of the that 35% of the mares continued show- or cycle manipulation. Aggressive maresfoal and placenta as neededing estrous behavior post-ovariectomy. might be candidates, but explore manage- Placement of birth monitoring transmitter2. I n 2007 Kamm et al. performed ament changes or other causes first. Daily turnoutretrospective study of 35 bilateral andBe aware that estrous behavior canMammary secrection monitoringunilateral ovariectomies, 23 of whichpersist post-ovariectomy, he said.were for behavioral reasons. Based onAt the time of Foaling:survey results, 22% of owners were dis- Removing Uterine Marbles Attendance and assistance (if needed) by satisfied with the procedure, primarilyHistorically, vets have inserted a marbleReproductive Medicine veterinariansdue to a lack of behavior changes. into a mares uterus to manage her estrousPlacental evaluation3.In 2007 Hedberg et al. compared ad- cycles. The theory? The marble would actColostrum quality evaluationrenocorticotropic hormones effect onlike an embryo and trick her body into testosterone and estradiol levels in fivethinking she was pregnant, thus eliminat- Physical exam of foal, enema mares before and after ovariectomy.ing estrus-related behaviors. But lack ofadministrationThey teased ovariectomized maresefficacy and overall negative health effectsIgG test 12 hours after birthand found all still demonstrated sexualfrom prolonged placement have promptedPost-Foaling:receptiveness. They also showed moresome vets to call for their retirement, said days of estrus than when intact. Daily turnout for mare and foal4.In 2015 Roessner et al. completed aTwice daily physical exams for mare and study of 20 bilateral ovariectomies per- foalformed for behavioral or performancePost-foaling reproductive examination of reasons and compared improvementthe marefrom altrenogest therapy alone to thatEasy access to the Cornell Universitypost-ovariectomy. The ovariectomies re- Equine Hospitalsulted in significantly better outcomes than therapy using altrenogest, but 30%We also offer mare breeding servicesof mares still showed estrous behavior.Based on these results, ovaries are notCONTACT US TODAYessential for estrous behavior, said Crab-tree. Ovariectomy might even make the607-253-3100situation worse, as estrous behavior may become irregular or persistent, he said.COURTESY DR. JAMES CRABTREEIts not totally clear why ovariectomized Sterile polymethylmethacrylate spheres are safer mares continue showing reproductivethan uterine glass balls for estrous suppression.March 2018THE HORSE AAEP Wrap-Up TheHorse.com/AAEP2017 A29'