Ovariectomy in horses refers to the surgical removal of one or both ovaries. This procedure is typically performed for various medical or behavioral reasons, such as the management of ovarian tumors, prevention of estrus-related behavioral issues, or as part of a larger reproductive management strategy. Ovariectomy can be performed using different surgical techniques, including laparoscopic and traditional open surgery, each with specific indications, advantages, and potential complications. This topic encompasses a range of peer-reviewed research studies and scholarly articles that explore the indications, methodologies, outcomes, and post-operative care associated with ovariectomy in equine patients.
Holtan DW, Squires EL, Lapin DR, Ginther OJ.Pony mares were bilaterally ovariectomized at different stages of pregnancy between Days 25 and 210. Abortion or fetal resorption occurred within 2 to 6 days after operations in all 14 mares ovariectomized between Days 25 and 45 and after an interval of 10 to 15 days in 9 of 20 other ovariectomized between 50 and 70 days. All 12 mares ovariectomized on either 140 or 210 days carried their foals to normal term. The termination of early pregnancy was preceded by a loss of uterine tone and of a palpable uterine bulge. The mean length of gestation in all mares in which pregnancy was not interrupte...
Terqui M, Palmer E.Plasma total (conjugated + unconjugated) oestrogens were measured from Day 0 to 100 of pregnancy and compared with the levels found during the oestrous cycle. From Day 0 to 35 of gestation, the concentrations were similar to those during dioestrus. An increase in total oestrogens between Days 35 and 40 was followed by a plateau of 3 ng/ml between Days 40 and 60 which was slightly higher than preovulatory concentrations. This first increase in total oestrogen level was produced by the ovaries since values were suppressed after ovariectomy; stimulation may be due indirectly to PMSG causing folli...
Garcia MC, Ginther OJ.Six pony mares were ovariectomized (OVX) on day 16 of diestrus during June and July, 1972, to study short term changes in plasma luteinizing hormone (LH) concentrations. Plasma LH was higher (P less than .05) 3 days after OVX (1.76 ng/ml) than the day after OVX (1.01 ng/ml), and a gradual increase occurred over the first 2 weeks. Elevated plasma LH concentrations similar to mid-estrus levels were present from the 2nd to 11th week post-OVX. In another experiment, the same 6 OVX mares were bled once a month from February, 1973, to January, 1974, to study long-term changes in plasma LH in relatio...
Lovell JD, Stabenfeldt GH, Hughes JP, Evans JW.The levels of progesterone and total progestins increased during late pregnancy and then fell dramatically during the last few days before parturition, although birth occurred in the presence of significant amounts of plasma progesterone. Oestrogen levels decreased slowly but insignificantly until birth occurred, and then remained at a low level until the post-partum oestrus 10 to 12 days later. Total 11beta-hydroxycorticosteroids were unchanged from Day 45 before to Day 15 after birth. The endocrine pattern of one ovariectomized pregnant mare during the last month of gestation was similar to ...
McIntosh JE, Moor RM, Allen WR.The process involved in the disappearance of PMSG from the blood of sheep, following a single intravenous injection, has been separated into two exponential components. Values (mean plus or minus S.E.) calculated from experiments on five animals were: metabolic clearance rate (37.8 plus or minus 1.6 ml hr-minus 1); rate constant of disposal (0.0315 plus or minus 0.0016 hr-minus 1); half-time of disposal (21.2 plus or minus 1.1 hr). The stage of the oestrous cycle, ovariectomy and the dose of PMSG used had no apparent effect on these values.
Dunay MP, Németh T, Makra Z, Izing S, Bodó G.In the present series of cases, 8 laparoscopic cryptorchidectomies and 4 laparoscopic ovariectomies were carried out in sedated standing horses. Sedation involved a lesser anaesthesiological risk than does general anaesthesia. As compared to laparotomic exposure, the minimally invasive laparoscopic intervention provided better visualisation, shorter operative time and faster recovery. The blood vessels supplying the testes and ovaries and the suspensory ligaments of the organs were sealed and cut with EnSeal®, an adaptive bipolar electrosurgical blood vessel- and tissue-sealing device. The cl...
Smith SE, Devine DV.To determine the feasibility of hand-assisted laparoscopic ovariectomy via colpotomy for bilateral ovariectomy in standing mares. Methods: Case series. Methods: Mares (n = 21) aged 2-21 years, weighing 312-582 kg. Methods: After a pilot study in 6 mares, the technique was used in 15 mares. Ovaries were identified and manipulated using 2 laparoscopic portals in the left paralumbar fossa. Transection and hemostasis of the ovarian pedicle was achieved using a LigaSure Atlas™ or chain écraseur. Ovaries were removed through a colpotomy by an assistant. Results: In 19 mares, both ovaries were suc...
Garcia MC, Ginther OJ.Six pony mares were ovariectomized (OVX) on day 16 of diestrus during June and July, 1972, to study short term changes in plasma luteinizing hormone (LH) concentrations. Plasma LH was higher (P less than .05) 3 days after OVX (1.76 ng/ml) than the day after OVX (1.01 ng/ml), and a gradual increase occurred over the first 2 weeks. Elevated plasma LH concentrations similar to mid-estrus levels were present from the 2nd to 11th week post-OVX. In another experiment, the same 6 OVX mares were bled once a month from February, 1973, to January, 1974, to study long-term changes in plasma LH in relatio...
Talboom JS, Engler-Chiurazzi EB, Whiteaker P, Simard AR, Lukas R, Acosta JI, Prokai L, Bimonte-Nelson HA.In women, ovarian hormone loss at menopause has been related to cognitive decline, and some studies suggest that estrogen-containing hormone therapy (HT) can mitigate these effects. Recently, the Women's Health Initiative study found that conjugated equine estrogens, the most commonly prescribed HT, do not benefit cognition. Isolated components of conjugated equine estrogens (tradename Premarin(®)) have been evaluated in vitro, with delta(8,9)-dehydroestrone (∆(8)E1) and equilin showing the strongest neuroprotective profiles. It has not been evaluated whether ∆(8)E1 or equilin impact cogn...
Fernández-Hernández P, Valero-González M, Fuentes-Romero B, Iglesias-García M, Ezquerra-Calvo LJ, Martín-Cuervo M, Macías-García B.Currently, for in vitro embryo production in live mares, immature oocytes are retrieved by transvaginal follicular aspiration or ovum pick up (OPU). Occasionally, ovarian abscesses have been described after OPU, but no current consensus exists on how to treat this condition. Objective: To describe diagnosis and successful treatment of ovarian abscesses in two mares subjected to OPU. Methods: Case report. Methods: Case records were reviewed and summarised. Results: In the first case, a pony mare showed tachypnoea, tachycardia, high temperature, leukocytosis, left hindlimb lameness and slight in...
Dzikiti TB, Maney JK, Thorogood J, Segabinazzi L, Peterson E, Dzikiti LN, Escobar A.Intravenous infusions of alpha-2 adrenoceptor sedatives and opioids can potentially facilitate surgery in donkeys while standing. Literature on this subject matter is scant. Objective: Evaluation of efficacy of sedation from α -adrenoceptors (dexmedetomidine or xylazine) and butorphanol during ovariectomy in standing donkeys. Methods: Randomised, masked in vivo experiment. Methods: Thirteen female donkeys were sedated with butorphanol (0.05 mg/kg bwt followed by 0.5 mg/kg bwt/h) IV. Concomitantly, 6 of the 13 jennies were sedated with dexmedetomidine 2.5 mcg/kg bwt followed by 2.5 mcg...
