Mares and horses are integral components of equine studies, focusing on the reproductive and behavioral aspects of equine biology. Mares, or adult female horses, play a significant role in breeding programs and are often studied for their reproductive physiology, gestation, and maternal behaviors. Horses, as a broader category, encompass both sexes and all age groups, providing a comprehensive view of equine anatomy, physiology, and behavior. Research in this area often investigates the differences and similarities between mares and other horses in terms of hormonal cycles, reproductive health, and social interactions. This page compiles peer-reviewed studies and scholarly articles that explore the biological and behavioral characteristics of mares and horses, offering insights into their roles in equine science and management.
Milliken JE, Paccamonti DL, Shoemaker S, Green WH.A pseudohermaphrodite horse with aggressive stallion-like behavior and ambiguous external genitalia was gonadectomized. The hypoplastic gonads removed from the abdomen were confirmed by histologic examination to be testes. Examination of blood and fibroblasts revealed a 64,XX karyotype.
Drummer HE, Reynolds A, Studdert MJ, MacPherson CM, Crabb BS.Sera from 33 Australian thoroughbred mares were tested during an outbreak of equine herpesvirus 1 (EHV1) abortion with an enzyme-linked immunosorbant assay (ELISA) for the presence of EHV1-specific antibodies. The ELISA used a recombinant EHV1 antigen derived from glycoprotein G (gG) and distinguished antibodies to EHV1 from those of the antigenically related and widespread herpesvirus EHV4. Sera were obtained from most of the mares on three occasions, three, 13 and 67 days after the first abortion. Mares which were negative in the ELISA were kept separate from mares which were positive. A sec...
Tannus RJ, Thun R.A total of 259 normally fertile mares were examined gynecologically by means of rectal palpation and ultrasonography in order to record the presence of uterine cysts and pregnancy. The incidence of endometrial cysts was 22.4%. Of the 95 cysts observed during the trial, 87.4% were located in the middle and posterior segments of both uterine horns. The size of all endometrial cysts ranged between 3 and 48 mm. When all mares were assigned to three age groups, A 14 years (n = 26), a significant (P < 0.01) increase in the number of endometrial cysts was observed with advancing age (4.3%, 29.1% ...
Belz JP, Glatzel PS.Because of the mare's ability to conceive very soon post partum a thoroughly performed control of the puerperal period is of particular importance. Cytological examinations of uterine content and histological examinations of uterine biopsy specimens provide more detailed information than microbiological examinations of uterine swabs. Uterine content and uterus biopsy specimens of 55 mares were examined histologically on days 3, 6 and 9 post partum. We observed a heavy polymorphonuclear reaction of the endometrium following disturbed puerperal processes especially in cases of retained placenta....
el-Komy AA.The pharmacokinetics of piperacillin (430 mg/kg.b.wt.) and cephapirin (20 mg/kg.b.wt.) were investigated following a single intravenous and intramuscular injection in normal mares. The serum concentration-time curve following a single intravenous injection of both antibiotics obeyed a two-compartment open model. After intravenous dose, piperacillin and cephapirin were transferred from central to peripheral compartment (k12) with values 0.46 and 0.52 h-1, while their passages from peripheral to central compartment (k21) were equal to 0.56 and 0.49 h-1, respectively. The elimination half-lives [...
Berghuis GA, Wesselink HG.Twenty nine mares with retained fetal membranes were treated IV with an oxytocine infusion. Within two hours the placenta released in 24 mares (83%). Twenty six (90%) mares got pregnant during the same season.
Sticker LS, Thompson DL, Fernandez JM, Bunting LD, DePew CL.Sixteen light horse mares were fed diets of bermudagrass hay and a corn/cottonseed hull-based supplement formulated to contain either 100% (control) or 50% (restricted) of the protein and(or) energy requirements for maintenance in a 2 x 2 factorial arrangement of treatments. Plasma IGF-I, prolactin, cortisol, triiodothyronine, and thyroxine were monitored for 33 d. On the 27th d, frequent blood samples were drawn throughout the day for the measurement of growth hormone (GH), and on the 29th d, an epinephrine challenge and an i.v. glucose tolerance test (IVGTT) were performed in the morning and...
Del Campo MR, Donoso X, Parrish JJ, Ginther OJ.Equine oocytes (n = 537) were collected from slaughterhouse ovaries (n = 118 mares) by scraping the internal follicular wall. Preculture record was made of the appearance of oocyte investments (no cumulus, corona radiata only, compact cumulus, expanded cumulus), appearance of cytoplasm (homogeneous, condensed heterogeneous/fragmented), and nuclear maturation stages (germinal vesicle, germinal-vesicle breakdown, metaphase I, metaphase II, degenerated). There was no difference between follicles > 30 mm and follicles < or = 30 mm in the preculture frequency distribution among the 5 nuclear stages...
Johnston GM, Taylor PM, Holmes MA, Wood JL.The Confidential Enquiry into Perioperative Equine Fatalities (CEPEF-1) is an observational multi-institutional prospective study of recovery outcome at 7 days post operatively, as called for by Steffey (1991). Data from 6,255 general anaesthetics (February 91-March 93) were submitted confidentially by 62 clinics. The outcomes of 333 cases which were subjected to euthanasia and which were not classified 'alive' or 'died' at 7 days, were excluded from the analysis. The remaining 5922 cases were analysed to identify risk ratios (RR) between survivors and nonsurvivors for a variety of factors. Th...
Guillaume D, Rio N, Toutain PL.The aims of the present study were to determine basic kinetic parameters and the nycthemeral production rate of melatonin in the horse. Seven pony mares were used for the kinetic studies. Five other pony mares were used under long and short days for the production rate studies. Melatonin was administered by intravenous, oral, and intragastric routes at different dose levels. The plasma melatonin clearance was 1.02 +/- 0.31 l.kg-1.h-1, and the volume of distribution was 0.89 +/- 0.53 l/kg for the 0.4 microgram/kg melatonin dose. The systemic availability after oral and intragastric administrati...
Heilkenbrinker T, Schubert TS, Oetjen J, Pózvári M, Frerking H.In this thesis the influence of pneumo-vagina on the microbiological colonization of the genital tract and their manifestation in cytological smears was examined. For mares with poor vulval conformation a comparison of the bacterial growth before and after plastic surgery of the vulva and vestibulum was carried out, as well as the registration of conception rates after operation and insemination. The biggest reduction of the bacterial content in the reproductive tract was found between vestibulum and cranial section of the vagina. The increased number of contaminant bacteria in the cranial sec...
Sams R, Gerken DF, Ashcraft SM.The pharmacokinetics and urinary excretion of ketoprofen in six healthy mares after the first and last of five daily intravenous doses of 2.2 mg of ketoprofen per kg body weight were investigated using a high-performance liquid chromatographic (HPLC) method for determining plasma and urinary ketoprofen concentrations. Plasma ketoprofen concentrations declined triexponentially after each dose with no significant differences in plasma concentrations or pharmacokinetic parameter values between the first and last doses. The harmonic mean of the terminal elimination half-life of ketoprofen after th...
Stock AE, Emeny RT, Sirois J, Fortune JE.It is not known whether the equine preovulatory follicle produces oxytocin or is a target tissue for oxytocin, as has been reported for other species, especially ruminants. Bovine granulosa cells secrete oxytocin, and oxytocin modulates the production of progesterone by granulosa cells in vitro. We examined whether oxytocin plays a comparable role in the equine preovulatory follicle. To test the hypothesis that the equine preovulatory follicle produces oxytocin during estrus and that its production increases in late estrus, preovulatory follicles were isolated during early (Days 1 to 2; n = 4)...
Troedsson MH, Scott MA, Liu IK.Four intrauterine treatment strategies were evaluated for effectiveness in mares that were confirmed to be susceptible to chronic uterine infection. Pretreatment samples were obtained at detection of estrus, and a genital strain of Streptococcus zooepidemicus was infused into the uterus when a preovulatory (> 35 mm) follicle was detected. At 12 hours after inoculation, mares were assigned to 1 of 4 selected treatment groups: autologous plasma, 100 ml (n = 5); potassium penicillin, 5 million U in 100 ml of phosphate-buffered saline solution (PBSS; n = 5); 10 mg of prostaglandin F2 alpha in 1...
Long MT, Goetz TE, Whiteley HE, Kakoma I, Lock TE.Two pregnant mares diagnosed as having equine monocytic ehrlichiosis based on history, clinical signs, and high serum antibody titers to Ehrlichia risticii aborted subsequent to recovery from illness. Mare 1 and mare 2 experienced clinical illness at 120 and 143 days of gestation and aborted at 203 and 226 days of gestation, respectively. The fetuses were expelled in fresh condition, and both mares retained their placentas upon abortion. Gross findings for the fetuses included meconium staining and petechiation of external surfaces. Internally, there was increased volume of feces within the sm...
Lea RG, Stewart F, Allen WR, Ohno I, Clark DA.Endometrial tissue from the gravid uterine horn of pregnant mares was examined by northern analysis and in situ hybridization for mRNA that hybridized to cDNA and RNA probes generated from a mouse TGF-beta 2 1.2 kb cDNA clone. The mouse cDNA probe hybridized to characteristic TGF-beta 2 mRNA transcripts on a northern blot of total RNA isolated from horse endometrium collected at day 45 of gestation. Two major 4.0 and 3.5 kb transcripts and possibly a minor 1.6 kb transcript were observed, consistent with specific hybridization to equine TGF-beta 2 mRNA. By in situ hybridization, riboprobes tra...
Gomez-Cuetara C, Flores JM, Sanchez J, Rodriguez A, Sanchez MA.An histological study of the postpartum period in 29 mares was carried out. Uterine biopsies were taken daily during the first 10 days postpartum in a total of 87 samples. At day 0, equine endometrium was characterized in the surface by the presence of regularly ordered microcaruncles; the stratum spongiosum was oedematous and contained distended and scarce glands. Degenerative changes in microcaruncles and endometrial glands were present on day 1 postpartum. The epithelium of the microcaruncles from 2 to 5 days postpartum showed cytoplasmic vacuolization, karyorrhexis and an inflammatory reac...
Santschi EM, Adams SB, Robertson JT, DeBowes RM, Mitten LA, Sojka JE.Six mares had ovariohysterectomy performed for chronic pyometra associated with cervical abnormalities, uterine neoplasia, or removal of a macerated fetus. Ovariohysterectomy was performed through a ventral midline incision with access to the ovarian and uterine vessels aided by traction on the uterus and retraction of abdominal viscera. Abdominal pain, the most common complication after surgery, occurred in four mares but resolved within 36 hours. Peritonitis occurred in two mares; one mare was subsequently euthanatized. Other complications that resolved with treatment included infection of t...
McDowell KJ, Adams MH, Franklin KM, Baker CB.A cDNA library was constructed from poly(A) RNA obtained from Day 14 nonbred equine endometrium. A cDNA probe for porcine retinol-binding protein (RBP) was used to screen the library, and a complete cDNA sequence (1133 bp, excluding the poly(A) tail) was obtained. Endometrial biopsies were obtained from cycling, nonbred mares at Days 0, 1, 4, 8, 10, 11, 13, and 15 and from pregnant mares at Days 11, 13, 15, and 17 after ovulation (n = 2 mares each day). Endometrial biopsies were also taken from 18 noncycling anestrous mares after the following treatments: C (vehicle control for 1 day, n = 3), ...
Rieder N, Beelitz P, Gothe R.In this epidemiological survey 30 foals and their mares from seven breeding farms were investigated. Six farms used wide spectrum anthelmintics strategically at least for three years, on one farm no anthelmintic prophylaxis was practiced. Excretion of P.-equorum-eggs occurred in all breeding farms and in 80% of the foals, but in only one mare. In foals infection with roundworms was detected at the earliest 85 days post partum. Before first shedding of P.-equorum-eggs wide spectrum anthelmintics had been administered to two and to one foal(s) one and two times, respectively, to four animals thr...
Kikuchi N, Blakeslee JR, Hiramune T.Plasmid profiles of Klebsiella pneumoniae isolated from horses were examined. Thirty-nine strains of K. pneumoniae capsular type 1 (K1) isolated from cervical swabs of mares suffering from metritis, and from semen of stallions showed similar plasmid profile patterns, and all strains possessed a 125 megadaltons (Md) plasmid. There was no difference in plasmid profiles between the heavily-encapsulated and the less heavily-encapsulated strains of K. pneumoniae K1. Non-capsulated variants derived from the strains of K1 showed the same plasmid profile pattern as the parent strains. Plasmid profiles...
Cudd TA, LeBlanc M, Silver M, Norman W, Madison J, Keller-Wood M, Wood CE.Fetal maturation and the timing of parturition in both sheep and primates are thought to be controlled by the hypothalamic-pituitary-adrenal axis but little is known about the endocrinology of the equine fetus. We investigated the ontogeny of plasma concentrations of adrenocorticotropic hormone (ACTH), cortisol and corticosteroid binding capacity in the late-gestation fetal horse. We also wished to determine whether there is ultradian rhythmic release of ACTH and cortisol in fetal horses and we compared fetuses to maternal and non-pregnant adult horses. Six fetuses, 278-304 days gestation (ter...
McCartan CG, Russell MM, Wood JL, Mumford JA.An outbreak of equine herpesvirus-1 (EHV-1) occurred on a large stud farm with 133 mares, 54 foals and four stallions, and at least 85 mares, 22 foals and three stallions were infected. Clinical disease was observed in 16 mares, two stallions and 13 foals and the predominant clinical signs were scrotal oedema, ataxia and loss of libido in the stallions, ataxia and recumbency in the mares and uveitis and nasal discharge in the foals, although pneumonia and colic with intussusception were also recorded at autopsy. Neurological disease was more common in the mares nursing foals (12 of 38 infected...
Bollwein H, Weber F, Steffen S, Stolla R.In previous studies, transrectal color Doppler sonography was used to demonstrate an increase in genital blood flow resistance in subfertile mares. The objectives of the present study were to determine the effects of an anticoagulant (acetylsalicylic acid) and a vasodilator (captopril) on uterine and ovarian perfusion and plasma progesterone concentrations in cycling mares. From Day 1 to 11 of an estrous cycle (Day 0=day of ovulation following prostaglandin-induced luteolysis), five Trotter mares were given 2500 mg lactose, 2500 mg ASA, or 50 mg captopril twice daily in their feed (one compoun...
Derar RI, Maeda Y, Hoque SM, Osawa T, Watanabe G, Taya K, Miyake Y.Two pony mares were immunized against recombinant porcine inhibin alpha subunit three times with 39 day intervals. Clinical findings and endocrinological changes before immunization were taken as the control. The first significant rise in the anti-inhibin titre (P<0.05) in the circulation was found 27 days after the first injection. Maximum binding activity was reached by the 12th day after the second booster dose. The number of small, medium and large sized follicles had increased significantly compared to before immunization (11.75 +/- 4.30, 2.75 +/- 0.69 and 2.51 +/- 0.63 vs 6.50 +/- 1.4...
Elshalofy A, Wagener K, Weber K, Blanco M, Bauersachs S, Bollwein H.This study aimed to investigate the susceptibility to persistent breeding-induced endometritis (PBIE). Cytobrush samples were collected from 81 broodmares 1-3 days before artificial insemination (AI). Susceptibility to PBIE was evaluated by the presence of ≥ 2 cm of intrauterine fluid 24 h after AI, besides the fertility was determined by a sonographic pregnancy diagnosis 2 weeks after ovulation. RNA expressions were compared between susceptible non-pregnant (SNP) mares (n=9) and resistant pregnant (RP) mares (n=9) as well as between susceptible pregnant (SP) mares (n=9) and susceptible non-...
Otzen H, Sieme H, Oldenhof H, Kassens A, Ertmer F, Rode K, Müller K, Klose K, Rohn K, Schoon HA, Meinecke B.The aim of this study was to evaluate the uterine blood supply and endometrial vessel architecture, during the equine estrous cycle. Narrow Band Imaging (NBI) hysteroscopy was used for evaluating changes in the endometrial vasculature during the estrous cycle [six mares, d 0 (representing the day of ovulation), d 6 and 11 in four locations]. In addition, endometrial biopsy samples were used for immunodetection of markers for angiogenesis (Vascular Endothelial Growth Factor A, its receptor 2, as well as angiopoietin-2 and its receptor-tyrosine-kinase Tie2) during the estrous cycle (three mares,...
Carluccio A, Contri A, Tosi U, De Amicis I, De Fanti C.To determine survival rate, complications, and short-term fertility rate after fetotomy in mares. Methods: Retrospective study. Methods: 72 mares with severe dystocia. Methods: Records from 1991 to 2005 were searched for mares with dystocia in which a fetotomy was performed. Data relating to presentation and position of foals; survival rate, complications, and short-term fertility rate in mares; and 45-day pregnancy rate in mares bred 2 to 3 months after fetotomy were recorded. Results: Anterior fetal presentation was detected for 54 of 72 (75%) mares, posterior presentation was detected for 1...
Thomas PG, Ball BA, Ignotz GG, Dobrinski I, Parks JE, Currie WB.Before fertilization, equine spermatozoa adhere to oviduct epithelial cells (OEC) of the mare. The biochemical basis for this adhesion has not been determined. Our objective was to produce an antiserum to block this interaction. Ejaculated spermatozoa were subjected to nitrogen cavitation and spermatozoal plasma membranes enriched by sucrose density gradient centrifugation; membrane enrichment was confirmed by comparative alkaline phosphatase analysis, electron microscopy, and one- and two-dimensional PAGE. Periacrosomal plasma membrane was used as an immunogen for the production of an antiser...
Aurich C, Budik S.Although the horse is a seasonal breeding species, a considerable number of mares continue to cycle throughout autumn and winter. Slower equine embryo growth during the non-breeding season has been hypothesized, and because smaller embryo size is beneficial for cryopreservation, embryo collection outside the breeding season could be an interesting approach for the production of frozen horse embryos. In the present retrospective study, we have therefore analysed embryo recovery rates and conceptus size in mares (n = 30) throughout the year. Conceptus diameter was either size determined after co...
Taverne MA.For the past few years, two-dimensional diagnostic ultrasound methods have become available to veterinary medicine. In particular, linear-array real-time ultrasound would appear to be a very suitable diagnostic tool in the examination of the female genital organs of domestic mammals. The principles of this technique and the equipment available are described, and particular attention is paid to the method by which a diagnosis of pregnancy may be established in various animal species. In dogs and goats shaving will have to be done before the sound-transmitting/receiving transducer can be placed ...
Ginther OJ, Jacob JC, Gastal MO, Gastal EL, Beg MA.Ablation of follicles > or = 6 mm in diameter and treatment with PGF2alpha 10 days after ovulation were used to induce the development of ovulatory waves. Comparisons were made between induced waves with one (33 waves, 72%) and multiple (13 waves, 28%) ovulatory follicles. Diameter deviation was defined as the separation of follicles into dominant and subordinate categories. Multiple ovulatory follicles were preceded by more (p or = 20 mm at the beginning of deviation, higher LH preceding deviation (approached significance, p < 0.08), lower (p < 0.05) concentrations of FSH on the day...
Howden KJ.A Thoroughbred mare was presented for stallion-like behavior. Reproductive and ultrasonographic evaluation, testosterone assays, and karyotyping confirmed a diagnosis of androgen insensitivity syndrome (64, XY--testicular feminization). Surgery to remove abdominal testicles was successful in alleviating the behavioral abnormality. This condition is discussed with reference to the current literature. Une jument Thoroughbred a été présentée parce qu’elle avait un comportement d’étalon. Une évaluation reproductrice et échographique, des dosages de testostérone et un caryotypage ont c...
Padilla AW, Tobback C, Foote RH.A method for preparing stored unfrozen stallion spermatozoa for the zona-free hamster oocyte penetration test (HOPT) and a subsequent comparison of fresh and stored sperm by the HOPT were evaluated. In Experiment 1, sperm from 4 stallion ejaculates, cooled to 4 degrees C and stored for 24 h, were treated with 60, 90 and 120 microM of dilauroylphosphatidyl-choline (PC12) liposomes to initiate the acrosome reaction. The percentage of motile and acrosome-reacted (AR) sperm were recorded after 8, 15 and 30 min of incubation at 39 degrees C, by automated image analysis. Liposome concentration did n...
van Loon JP, van Oostrom H, Doornenbal A, Hellebrekers LJ.There is a need for objective evaluation and quantification of the efficacy of analgesic drugs and analgesic techniques in horses. Objective: To determine whether lumbosacral spinal cord somatosensory evoked potentials (SSEP) can be a useful and reliable tool to assess nociception in equines. Methods: SSEPs and electromyograms (EMG) from the epaxial muscles were recorded simultaneously, following electrical stimulation applied to the distal hindlimb in lightly anaesthetised Shetland ponies (n=7). In order to validate the model, the effect of increasing stimulus intensity was documented and the...
Davison LA, McManus CJ, Fitzgerald BP.In the mare, endogenous opioids have been implicated in the suppression of gonadotropin secretion during seasonal anestrus (AN). The present study tested whether continuation of reproductive activity during the nonbreeding season (NBS) reflects the absence of a seasonal shift in opioid tone compared to what occurs in AN mares. During the NBS, 11 AN and 8 luteal-phase mares received 0.1, 0.05, 0. 025 mg/kg naloxone (NAL) or vehicle on alternate days. Whereas cycling mares responded to all dosages of NAL, AN mares responded only to the higher dosages for FSH, and LH failed to increase at any dos...
Gao Y, Hannan MA, Murata K, Rajabi-Toustani R, Nambo Y.Equine-Assisted Therapy (EAT) is gaining popularity. Ultrasound examination is used to decrease the abortion rate in horses. In this study, to monitor fetal well-being throughout the gestation for EAT, we measured fetal heart rate (FHR), fetal eye orbit (FEO), fetal gonad length (FGL), fetal kidney length (FKL), and the combined thickness of the uterus and placenta (CTUP) by ultrasonography in pony mares. Additionally, we measured the plasma progesterone (P4) and estradiol (E2) concentrations in pregnant horses using enzyme immunoassay. The FGL peaked at week 32 and then decreased to term, and...
Köhne M, Ille N, Erber R, Adib Razavi MS, Walter I, Aurich C.Progestin concentration in plasma during the early luteal phase is crucial for endometrial function and conceptus development. We hypothesized that periovulatory gonadotrophin treatment via support of luteal function affects endometrial gene expression in horses. Effect of age was analyzed as well. Shetland mares (n = 8, age 4-25 years) were assigned to the following treatments during five consecutive cycles in alternating order following a cross-over design: treatment hCG/-: preovulatory injection of hCG, but no gonadotrophin injection at detection of ovulation, treatment -/hCG: no preovulat...
Strzemienski PJ, Dyer RM, Kenney RM.Neutrophils isolated from jugular blood of ovariectomized mares were studied for the effect of estradiol and progesterone on bactericidal activity against Staphylococcus aureus. In experiment 1, neutrophils obtained from 4 mares were tested for bactericidal activity by adding estradiol (43 pg/ml) or progesterone (6.4 ng/ml) to the bactericidal assay. In experiment 2, 3 of the 4 ovariectomized mares were given 2 mg of estradiol, IM, daily for 3 days. Eighteen days after the initial estradiol injection, mares were given 300 mg of progesterone, IM, for 6 days. Neutrophils from these mares were te...
Gastal EL, Gastal MO, Donadeu FX, Acosta TJ, Beg MA, Ginther OJ.Diameter of the preovulatory follicle, plasma concentrations of LH and estradiol, and vascularization of the follicle wall, based on color-Doppler signals, were characterized in 40 pony mares for 6 days preceding ovulation (Days -6 to -1; preovulatory period). Comparisons between the preovulatory periods preceding the first compared with a later ovulation during the year were used to study the relationships between LH and estradiol and between vascularization and estradiol. Diameter of the preovulatory follicle was greater (P<0.02) and concentration of LH was less (P<0.02) during the fir...
Shen Y, Ulaangerel T, Ren H, Davshilt T, Yi M, Li X, Xing J, Du M, Bai D, Dugarjav M, Bou G.The follicular fluid and oviduct fluid play major roles in oocyte maturation, sperm activation, and fertilization. To better understand the physiological environments for equine oocyte maturation and fertilization, here we conducted the proteome analysis and comparison on follicular fluids and oviduct fluids from the ovulatory side and the anovulatory side. The results showed that there is no significant difference between two side oviduct fluids, but a total of 71 differential abundance proteins (DAPs) were identified between two side follicular fluids, of which 9 are up-regulated and 62 are ...
Sampaio BFB, DeRossi R, Vieira N, Milan B, Ávila LG.The objective of the study was to compare the effects of caudal epidural bupivacaine and dexmedetomidine (DEX) combination, with bupivacaine or DEX plain for perineal analgesia in mares. Six healthy saddle mares weighing 330-370 kg and aged 10-15 years were used in this study. Each mare was assigned to receive three treatments: 0.04 mg/kg 0.25% bupivacaine (BP), 2 μg/kg DEX (DX), or 0.02 mg/kg bupivacaine and 1 μg/kg DEX (BPDX). The order of treatments was randomized. All drugs were injected into the caudal epidural space (Co1-Co2) through a 16-G Tuohy epidural needle. After the epidur...
Lopes Ede P, Siqueira JB, Pinho RO, Guimarães JD, Rocha AN, de Carvalho GR, Torres CA.The objective of this study is to evaluate the reproductive efficiency in donors and recipient Mangalarga Marchador mares in commercial programmes of embryo transfer (ET) and the effects of some reproductive characteristics and ET methodology on conception rates in the recipient mares. A total of 1140 flushing procedures were performed and 830 embryos (72.8%) were recovered. There were no differences between the rates of embryonic recovery in the different breeding seasons (p > 0.05) and 92.8% of the recovered embryos were 8-9 days old. There was no difference in the embryonic recovery regardi...
Vitte A, Rossignol F, Mespoulhes-Rivière C, Lechartier A, Röecken M.To report a combination of standing laparoscopic technique for intra-abdominal dissection of the mesovarial pedicle followed by a limited ventral median celiotomy under general anesthesia for removal of enlarged ovaries in mares. Methods: Case series. Methods: Mares (n = 20) aged 3-22 years with unilateral enlarged ovaries. Methods: Enlarged ovaries were confirmed by transrectal palpation and ultrasonography. After sedation, 3 laparoscopic portals were made in the paralumbar fossa. The mesovarium was desensitized and dissected using a vessel sealing device, and the ovary was left free in t...
Gao Y, Yoshida S, Takeyama A, Tagami M, Rajabi-Toustani R, Tsogtgerel M, Nambo Y.Ultrasound examination during late gestation is one of the best methods for monitoring potential pregnancy risks. Enlarged bladder is a urological disorder rarely observed in equine fetuses. This clinical case report aimed to present a case illustrating the development of equine fetal enlarged bladder using transabdominal ultrasound examinations and maternal hormone evaluation during gestation. An 8-year-old Hokkaido native pony was impregnated by embryo transfer, and at 215 days of gestation, abnormalities of the fetal bladder were detected. The bladder volume increased with gestational age, ...
Jung C, Hospes R, Bostedt H, Litzke LF.To report on the outcome of surgical treatment of uterine torsion in preterm mares. Methods: Retrospective case series of pregnant mares with uterine torsion presented to the Clinic for Obstetrics, Gynaecology and Andrology of Large and Small Animals. Methods: Hospital records of all pregnant mares that underwent ventral midline laparotomy for uterine torsion between 1998 and 2004 were reviewed. The signalment, history, clinical signs, results of diagnostic procedures, direction and degree of the uterine twist, treatment and outcome were retrieved from each case record. Results: This study com...
Młodawska W, Palmer E, Duchamp G, Okólski A, Bézard J.The binding of a spermatozoon to the zona pellucida is the first step in fertilization. The number of spermatozoa bound to a zona pellucida may reflect the functional status of both the oocyte and spermatozoa. The aim of the present study was to determine whether the stage of maturation of the equine oocyte affects the capacity of the zona pellucida to bind with spermatozoa. Cumulus-oocyte complexes (COCs) were collected from the ovaries of mares from abattoirs or were obtained in vivo by ultrasound-guided follicular aspiration. Oocytes were inseminated directly after collection or after 30 h ...
Willis P, Sekhar KN, Brooks P, Fayrer-Hosken RA.To characterize further the events involved in fertilization and early embryonic development in the mare, effect of the estrous cycle on oviductal fluid proteins was investigated. Five mares had indwelling cannulas placed in their oviducts so that fluid could be collected throughout the estrous cycle. Daily fluid volumes were recorded and mares were monitored for signs of standing estrus. Oviductal fluid samples were pooled across mares according to stage of cycle (either estrus or nonestrus) for further analysis. Two-dimensional polyacrylamide gel electrophoresis (PAGE) was used to determine ...
Veronesi MC, Faustini M, Villani M, Kindahl H, Galeati G, Battocchio M.The aim of the present study was to highlight the effect of two different techniques of one embryo crushing on some hormonal changes. Ten twinning mares were submitted to the mobile or fixed manual crushing of one blastocyst within day 19 after the last mating. Blood sample was collected from 20 min before to 90 min, 24 and 72 h after the procedure was performed to analyse 15-ketodihydro-PGF(2alpha), cortisol and progesterone plasma concentrations. Singleton pregnancy diagnosis was checked 72 h after crushing and at term of pregnancy. Because the unwanted crushing of both embryos occurred in o...
Choi YH, Love LB, Varner DD, Hinrichs K.The effect of medium-to-embryo ratio on blastocyst development of equine embryos from oocytes with compact cumuli was evaluated in the present experiment. In addition, two methods for holding oocytes before in vitro maturation were compared. In Experiment 1, oocytes cultured with roscovitine for 16-18h before maturation were fertilized by intracytoplasmic sperm injection and cultured individually in 2.5, 5, 10 or 50microl droplets. In Experiment 2, oocytes were either cultured with roscovitine or held in a modified M199 with 20% serum at room temperature (EH treatment) for 16-18h, then matured...
Romagnoli U, Macchi E, Romano G, Motta M, Accornero P, Baratta M.The aim of this work is to investigate on plasma profiles of leptin and estradiol 17beta during the interpartum period and leptin concentrations in the milk and in the colostrum during the period from parturition to the successive delivery in mare. Leptin plasma concentration varied from 5.1+/-2.3 ng/ml after the first parturition (week 0) to 3.0+/-0.7 at week 21 (p<0.05), then it increased to maximal level at week 49 (6.9+/-1.0 ng/ml, p<0.05). Leptin concentration in the colostrum and in the milk has been significantly (p<0.05) higher than that in plasma samples at week 1 (milk 8.8+/...
Watson ED, Heald M, Tsigos A, Leask R, Steele M, Groome NP, Riley SC.Ten mares were studied from February (winter anoestrus) to their second ovulation in the breeding season to investigate the relationship between resumption of ovarian cyclicity in the spring and circulating concentrations of FSH, inhibin A and inhibin isoforms containing pro- and -alphaC immunoreactivity. An additional four mares were studied during one oestrous cycle. Growth and regression of ovarian follicles were monitored by transrectal ultrasonography. The frequency of blood sampling varied from three times a week to once a day, depending on the follicular activity present. Concentrations...
Jeawon SS, Katz LM, Galvin NP, Fogarty UM, Duggan VE.Although umbilical cord blood gas analysis is considered the best way to assess in utero oxygenation in human neonates, there is limited evaluation of this method in equine neonatology. Our objectives were to assess the practicality of obtaining umbilical cord blood gas samples in the field and to determine umbilical cord arterial and venous blood gas reference intervals (RI) for healthy, newborn foals. Thoroughbred foals >320 days gestation from healthy mares with uneventful pregnancies at one stud farm were evaluated. All parturitions were observed, with paired umbilical arterial and venous ...
