Use of a glass ball to suppress behavioral estrus in mares

Use of a Glass Ball to Suppress Behavioral
Estrus in Mares
Gary J. Nie, DVM, MS, PhD, Diplomate ACT, Diplomate ABVP;Kristina E. Johnson, DVM; Timothy D. Braden, PhD; andJames G. W. Wenzel, DVM, MS, PhD, Diplomate ACT, Diplomate ACVPM A 35-mm glass ball placed in the uterus within 24 hours following ovulation will result in a prolongedluteal phase in approximately 40% of mares.
Progesterone levels remain elevated in these mares for Employing this technique avoids the need for daily administration of efficacious progestin products or intermittent administration of non-efficacious products for the purposes ofbehavioral estrus suppression in performance mares.
Sciences (Nie, Johnson, Wenzel); Department of Anatomy, Physiology, Pharmacology (Braden), Col-lege of Veterinary Medicine, Auburn University, AL 36849-5522. 2001 AAEP.
Introduction
Owners are seeking veterinary assistance more and concern regarding the off-label use of cattle implants more frequently to suppress behavioral estrus in is the potential regulatory consequences that may their performance mares, hoping that this will re- come about from the illegal use or abuse of such sult in the mares training or performing better.
Practitioners are then put in the precarious situa- Recent communications on a popular equine email tion, due to industry pressures, of having to employ list suggested that a small glass ball of ϳ30 mm in a variety of progestin products, off-label, without diameter, placed in the uterus of a mare, would of suppressing behavioral signs of estrus in most teal period results in continually elevated circulat- mares is to maintain sufficient levels of circulating ing progesterone levels sufficient to suppress sufficient level of progesterone or its equivalent can takes advantage of endogenous progesterone pro- be maintained is through the presence of a func- duction and avoids using other hormones, off-labeland without evidence of efficacy.
tional corpus luteum (CL), daily intramuscular ad-ministration of exogenous progesterone (e.g., Ն50mg in oil), or daily oral administration of a synthetic Materials and Methods
A 35-mm glass ballc is placed in the uterine body progestin products, labeled for use in other species, within 24 hours following ovulation.
have been demonstrated to be ineffective for sup- can be sterilized prior to placement using an auto- phase of a fluid cycle will avoid breakage.
however, that the progesterone profiles in these In preparation for placement of a uterine glass mares were very similar to those reported for mares ball (UGB) the perineum should be cleaned as for hysterectomized 3 days following ovulation.7 primary CL was present 70 days following ovulation sleeve, a UGB is carried vaginally to the caudal We found this was also true of mares that cal lumen and into the caudal uterine body.
experienced prolonged luteal function in response to lowing placement, the UGB can be located per rectum and pushed forward to the horn-body junc- The procedures for placement and removal are After placing a UGB, 1 gm of ticarcillin is relatively simple and the UGB does not appear to be infused to cover for bacterial contamination.
an ecbolic can be administered to help clear the takes advantage of endogenous progesterone pro- uterus of contaminants before the cervical lumen duction to suppress behavioral estrus.
closes under the influence of progesterone.
teal function was not maintained in every mare, In order to facilitate UGB removal, a mare should those in which function was prolonged had proges- terone levels Ͼ1 ng/ml for roughly 3 months. We learned procedure with a minimum of practice.
did not follow the mares beyond their subsequent casionally a mare may need to be lightly sedated ovulation, though we expect that if the UGB had been left in the uterus each mare would have expe- plished by manipulating the UGB per rectum and rienced another prolonged luteal period.
moving it caudally toward the cervix.
researcher related information to us about 2 mares expelled through a relaxed cervix and into the cra- in which a UGB had been placed and had experi- fully dilated, a gloved hand can be taken in per ministration of prostaglandin, both mares returned vagina to retrieve the UGB from the caudal cervical to estrus, retained the UGB, ovulated, and again experienced prolonged luteal function.
Glass balls were removed following 4 consecutive None of our mares experienced any endometrial ovulations subsequent to placement when prolonged damage detectable with ultrasonic or histologic ex- luteal function did not occur or following ovulation at the end of a prolonged luteal phase.
bred following removal of the UGB are demonstrat-ing that conception is not impaired.
the anecdotal information provided on the veterinar- In a study we conducted, 5 of 12 mares (41.7%) experienced prolonged luteal function which lasted a dicated that no changes are detectable in the uterine mean of 88.8 days following placement of a 35-mm wall by palpation or ultrasonography.
removal the mare will come back into heat and will levels were measured to determine luteal func- This veterinarian also indicated that the balls will A mare was defined as having functional lu- occasionally be expelled spontaneously, though he teal tissue as long as progesterone levels remained used a 35-mm UGB instead of the 30-mm size sug- longed luteal function maintained a CL for 76, 78, data, we placed the UGB following ovulation.
mares had a mean interovulatory interval of 20.0 findings agree with the preliminary information that spontaneous expulsion was not a problem.
Endometrial biopsies were also evaluated before Our results, however were not quite as good as those UGB placement and following removal, in order to determine if there were any negative effects on the technique works in at least 75% of cases.
found that ϳ40% of mares experience prolonged lu- served between the pre-placement and post-removal No detrimental effects were observed in our study, from the mares by mid-fall of last year.
though one might suspect that inducing prolonged summer 2001, 8 of 12 mares have been bred and 3 of luteal function could result in endometrial damage if microbial contaminants are introduced when the amount of fluid around the UGB, as observed with Discussion
ultrasound, a day or so following placement.
We found that a 35-mm diameter glass ball placed in ever, the condition did not progress in any of the the uterus would result in prolonged luteal function Nevertheless, it may be advisable to exam- ine a mare with ultrasound several days following UGB placement to ensure a detectable endometritis This technique offers the advantage of suppress- 4. McCue PM, Lemons SS, Squires EL, et al.
ing behavioral estrus as a result of endogenous pro- vex-s implants in suppression of estrus in the mare.
5. Scheffrahn NS, Wiseman BS, Vincent DL, et al.
effective the need for daily administration of effica- tive hormone secretions in pony mares subsequent to ovulationcontrol during late winter.
Theriogenology 1982;17:571–585.
cious progestin products or intermittent administra- tion of off-label, non-efficacious products is avoided.
7. Squires EL, Garcia MC, Ginther OJ.
References and Footnotes
and hysterectomy on the ovaries of pony mares.
1. Hawkins DL, Neely DP, Stabenfeldt GH.
one concentrations derived from the administration of exoge-nous progesterone to ovariectomized mares.
aRegumate, Hoechst Roussel Vet, Warren, NJ 07059.
bDr. Randy J. T. deGreef, Messages to the Equine Clinicians dPeter F. Daels, Nouzilly, France, personal communication.

Source: http://listas.secyt.gov.ar/pipermail/aave/attachments/20131111/95fe90aa/attachment.pdf