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.
Pinto-Bravo P, Rebordão MR, Amaral A, Fernandes C, Galvão A, Silva E, Pessa-Santos P, Alexandre-Pires G, Roberto da Costa RP, Skarzynski DJ....The oviduct presents the ideal conditions for fertilization and early embryonic development. In this study, (i) vascularization pattern; (ii) microvascular density; (iii) transcripts of angiogenic factors (, , ) and their receptors-, , , respectively, and (iv) the relative protein abundance of those receptors were assessed in cyclic mares' oviducts. The oviductal artery, arterioles and their ramifications, viewed by means of vascular injection-corrosion, differed in the infundibulum, ampulla and isthmus. The isthmus, immunostained with CD31, presented the largest vascular area and the highest ...
Abraham M, Bauquier J.The peripartum period is critical in equine medicine for maintaining healthy mares, and ensuring the delivery of healthy neonatal foals. The field of perinatal mortality in horses is continuously evolving, with several advances being recently made in causes of perinatal fetal and foal loss. This review details the main causes of perinatal loss in horses, through late pregnancy, parturition and the neonatal period. Recent advances in identification of infectious organisms and indicators of survival in neonatal foals will be discussed. Continued advances in reproductive and neonatal medicine wil...
Robles M, Hammer C, Staniar B, Chavatte-Palmer P.Forage availability should cover most needs for mares bred during spring and summer. Out-of-season breeding, lack of access to pasture, or good quality forage calls for nutritional supplementation. Current evaluations of broodmare needs are based on fetoplacental tissue requirements, but do not consider endocrine changes or that the maternal diet quality affects long-term foal health. This article reviews pregnant mares' current nutritional recommendations. Secondly, fetoplacental developmental stages during gestation are outlined, defining critical periods in the context of the developmental ...
Lawless SP, Moorman VJ, Hendrickson DA, Mama KR.To compare efficacy and safety of a continuous rate infusion of detomidine hydrochloride and romifidine hydrochloride for standing elective bilateral laparoscopic ovariectomy in mares. Methods: Blinded, randomized prospective clinical study. Methods: Eighteen healthy mares presenting for elective bilateral ovariectomy METHODS: Mares were randomly assigned to one of two sedation protocols. Prior to surgery, baseline head height, heart rate, respiratory rate, and postural sway were recorded. An IV loading dose of α2-agonist (46 μg/kg romifidine or 13.9 μg/kg detomidine) was administered. S...
Nagy AM, Sathe SR, Atta AH, Hammam AMM, Hsu WH.In equine parturition, the role of progestins along with the nuclear progesterone receptor (nPR) signaling pathway in the placenta is not completely clarified. The progestins play an integral role in maintaining myometrial quiescence during the late stage of pregnancy via acting on nPR isoforms (PRA and PRB; PRB is more active than PRA). The current study aimed to determine the PRA and PRB expressions in the term equine placenta at the gene and protein levels. Six term equine placentas were used in this study. Reverse transcription polymerase chain reaction (RT-PCR) was used to quantify the mR...
Tuomola K, Mäki-Kihniä N, Valros A, Mykkänen A, Kujala-Wirth M.Bit-related oral lesions are common and may impair horse welfare. The aim of this study was to investigate the prevalence of oral lesions and their risk factors in a sample of Finnish event horses. The rostral part of the oral cavity (the bit area) of 208 event horses (127 warmbloods, 52 coldbloods, and 29 ponies) was examined in a voluntary inspection after the last competition phase, i.e., the cross-country test. Acute lesions were observed in 52% (109/208) of the horses. The lesion status was graded as no acute lesions for 48% (99/208), mild for 22% (45/208), moderate for 26% (55/208) and s...
Tongu EAO, Segabinazzi LGTM, Alvarenga ML, Monteiro A, Papa FO, Alvarenga MA.This study aimed to evaluate the effects of mesenchymal stem cell-conditioned medium (MSC-CM) on sperm parameters, intrauterine polymorphonuclear neutrophils (PMN), intrauterine fluid accumulation (IUF), and fertility in mares. In experiment 1, two ejaculates from ten stallions were extended to 50 million sperm/mL using a milk-based extender. Thereafter, 20 mL of extended semen was added of MSC-CM as follows: 0, 5, 10, 15, and 20 mL. Sperm kinetics and plasma membrane integrity were evaluated immediately after dilution (T0) and 2 h post-incubation at 37 °C (T2). In experiment 2, mares cha...
Kalpokas I, MartÃnez MN, Cavestany D, Perdigón F, Mattos RC, Meikle A.We investigated the early effects of the equine embryo on maternal serum concentrations of insulin-like growth factor 1 (IGF1), leptin and adiponectin, uterine immune cells and genes and proteins related to embryo development and the maintenance of pregnancy. Ipsilateral endometrial expression was assessed on Days 7 and 13 after ovulation for the following transcripts: oestrogen receptor ERα (ESR1), progesterone receptor (PGR), progestin and adipoQ receptor family member 5 (PAQR5), oxytocin receptor (OXTR), prostaglandin-endoperoxide synthase 2 (PTGS2), raf-1 proto-oncogene serine/threonine k...
Hicks GR, Fraser NS, Bertin FR.Although there are many hormonal changes associated with reproduction, the effects of ovulation and early pregnancy on adrenocorticotropic hormone (ACTH) and insulin concentrations are poorly described. We hypothesise that both ovulation and early pregnancy will alter ACTH and insulin concentrations in healthy mares. Eighteen mares showing no clinical signs suggestive of, or laboratory findings consistent with, pituitary pars intermedia dysfunction PPID and insulin dysregulation (ID) are enrolled. ACTH, cortisol, insulin and glucose concentrations are measured over their peri-ovulatory period,...
Ireland JL, McGowan CM.Research demonstrating insulin's causal role in endocrinopathic laminitis has greatly advanced understanding of equine laminitis. However, the degree to which this knowledge has been translated into clinical practice has not been assessed. This two-part study aimed to investigate veterinary surgeons' current diagnostic approach to laminitis, whether this had changed over time, and the impact of diagnosing an endocrinopathy on laminitis case management and outcome. Two cross-sectional online surveys of equine veterinary surgeons working within the UK were undertaken. The first study population ...
Dufour P, Courtois J, Seynaeve Y, Peeters S, Le Goff C, Cavalier E, Ponthier J.Steroid concentrations in serum are fluctuating during pregnancy of many mammal species. The current knowledge about endocrinology of gestation is mainly based on immunoassays. However, the lack of specificity of these assays hampers the reliability of the results. In the present work, we developed and validated a methodology associating liquid chromatography (LC) and mass spectrometry (MS) to simultaneously quantify, with high specificity and accuracy, estrone-3-sulfate (E3S), progesterone (PRO), estrone (E1) and estradiol (E2) in serum of two different mammal species. The sample preparation ...
Ono T, Inoue Y, Hisaeda K, Yamada Y, Hata A, Miyama TS, Shibano K, Kitagawa H, Ohzawa E, Iwata E.This study aimed to evaluate the influence of seasons and sex on body size and hematological and biochemistry parameters of Noma horses, a native Japanese breed. Body size was larger in winter than in summer. Laboratory testing variables, including erythrocytic parameters and urea nitrogen, total cholesterol, and creatinine kinase levels, were higher in winter, while the eosinophil count was higher in summer. These seasonal differences may be related to increased energy consumption of horses due to heat stress. The higher eosinophil counts may have been related to the dermatitis observed in su...
Jastrzębska E, Sadowska J, Wnuk-Pawlak E, Różańska-Boczula M, Janczarek I.This study aimed at assessing the behaviour of Konik geldings and mares, kept in a stable and in a free-range system, during behavioural tests regarded as a determinant of the exploration urge. A total of 19 Konik horses kept in individual stables and in a free-range system were included in the study. The experiment was conducted in five phases separated by five-day breaks. A one-stage passive human test was performed during the first phase, a three-stage active human test-2nd phase, a three-stage unknown object test-3rd phase, a two-stage unknown surface test-4th phase, and a one-stage test o...
Weese JS, Slovis N, Rousseau J.Understanding the epidemiology of Clostridium difficile is important for the development and assessment of infection prevention and control practices, as well as surveillance methods and interpretation of diagnostic testing results. Objective: Our objective was to longitudinally evaluate C. difficile shedding in neonatal foals and mares admitted to a referral hospital neonatal intensive care unit. Methods: Foals admitted to a neonatal intensive care unit, along with their dams. Methods: Rectal swabs were collected from mares and foals at admission, and then approximately every 3 days, when p...
Weller D, Franklin S, White P, Shea G, Fenner K, Wilson B, Wilkins C, McGreevy P.This article reports on the results of a survey of racehorse trainers (n = 112) outlining the reasons for tongue-tie (TT) and noseband (NB) use by Thoroughbred trainers (TBTs) (n = 72) and Standardbred trainers (SBTs) (n = 40). The study also investigated the reported effectiveness of TTs and possible complications arising from their use. Tongue-tie use was reported by 62.5% (n = 70) of racehorse trainers. The reasons for TT use varied between TBTs and SBTs. For TBTs, the most common reason for TT use was to prevent or reduce airway obstruction (72.3%, n = 34), followed closely by to prevent o...
Li J, Zhao Y, Gao Y, Zhu Y, Holyoak GR, Zeng S.Bacterial infections are the main causes of endometritis in mares. It is well known that the most common bacterial pathogen is Streptococcus equi subspecies zooepidemicus (SEZ). This structured review was completed according to the PRISMA procedure to search endometritis treatment protocols published between 1990 and 2020 it was our intent to evaluate the actual effects of different treatment protocols for endometritis caused by SEZ. The trials included were collected from Pubmed, CAB and Agricola. Ten articles with 116 horses and 17 different interventions were identified. The results of this...
Fedorka CE, Ball BA, Walker OF, McCormick ME, Scoggin KE, Kennedy LA, Squires EL, Troedsson MHT.Equine abortions are attributed to both infectious and noninfectious causes. Clinical extrapolations are often made from the experimental model for ascending placentitis towards other causes of fetal compromise, including various markers of inflammation, including the cytokines IL-2, 5, IL-6, IL-10, IFNγ, and TNF. It is unknown if these cytokine changes are noted under field conditions, or if they increase preceding other pregnancy related complications. To assess this, Thoroughbred mares (n = 702) had weekly blood obtained beginning in December 2013 and continuing until parturition. Fet...
Castro T, Jacob JC, Stefani G, Domingues RR, Ginther OJ.The concentrations of progesterone (P4) and a metabolite of PGF2α (PGFM) in mares were compared between the interovulatory interval (IOI; n = 8) and the corresponding days of pregnancy (n = 9). In daily blood samples, P4 increased between the day of ovulation (Day 0) and ∼Day 6 and then gradually decreased until the beginning of luteolysis in the IOI group. Before the beginning of luteolysis, there were no significant differences in P4 concentrations between the IOI and early pregnancy. In the IOI, PGFM concentration on the day before the beginning of luteolysis began to increase (P <Â...
Nielsen JM, Fog P, Bojesen AM.The breeding prognosis for a mare with fungal (yeast or mold) endometritis is generally considered poor. To our knowledge, however, no reports have been published on the expected pregnancy rate for mares diagnosed with a fungal infection. Insemination records from 3,223 mares inseminated at two stud farms were retrospectively examined. Mares diagnosed with fungal endometritis were all treated with uterine lavage using physiological saline, intrauterine deposition of 100 mg Clotrimazole vagitorial tablets and oxytocin (10 i.e., i.m.) for three consecutive days. From mares with signs of endometr...
Macpherson ML, Giguère S, Pozor MA, Burden CA, Berghaus LJ, Berghaus RD, Varner JC, Hayna JT, Benson SM, Randell SA, Lyle SK, Kelleman AA, Hart KA....Minimal evidence exists supporting therapeutic selections for equine placentitis. The goal of this study was to characterize the anti-inflammatory effects of firocoxib when administered to mares with placentitis. Mares (gestation D270-300) were assigned to: INFECT (n = 6; placentitis, no treatment), FIRO (n = 6; placentitis, firocoxib, 0.1 mg/kg, PO, daily), and NORM (n = 6; no infection/treatment). Allantoic fluid (8 hours, 24 hours, birth) and amniotic fluid (birth) were collected from mares after infection. Concentrations of IL-1β, IL-6, TNF-α, IL-10, PGF , and PGE in fluids were...
Fedorka CE, Scoggin KE, El-Sheikh Ali H, Loux SC, Dini P, Troedsson MHT, Ball BA.Ascending placentitis is the leading cause of abortion in the horse. Interleukin (IL)-6 is considered predictive of placental infection in other species, but little is understood regarding its role in the pathophysiology of ascending placentitis. Sub-acute ascending placentitis was induced via trans-cervical inoculation of S zooepidemicus, and various fluids/serum/tissues collected 8 days later. Concentrations of IL-6 were detected within fetal fluids and serum in inoculated (n = 6) and control (n = 6) mares. RNASeq was performed on the placenta (endometrium and chorioallantois) to asses...
Rivera Del Alamo MM, Katila T, Palviainen M, Reilas T.Intrauterine devices block luteolysis in cyclic mares, but the underlying mechanism is unknown. To clarify the mechanisms, the protein profile of the endometrial secretome was analyzed using two-dimensional difference gel electrophoresis (2D-DIGE). Twenty-seven mares were classified according to whether they were inseminated (AI) or had an intrauterine device (IUD), a water-filled plastic sphere, inserted into the uterus on Day 3 after ovulation. Uterine lavage fluids were collected on Day 15 from pregnant inseminated mares (AI-P; n = 8), non-pregnant inseminated mares (AI-N; n = 4), and m...
Cooper CJ, Arroyo LG, Pearl DL, Hewson J, Lillie BN.A survey of Ontario horse breeders was conducted in 2016 and retrospectively asked farm-level management questions regarding herd sizes, vaccination, respiratory disease, and abortion over the years 2014 to 2015. A total of 88 farm owners completed the survey, reporting 857 broodmares. Using logistic regression modelling, management influences on vaccine use, and the reporting of respiratory disease or abortion was investigated. Having veterinary records and the reasons for breeding were significantly associated with the odds of an abortion even after controlling for broodmare herd size. The o...
Catandi GD, Obeidat YM, Broeckling CD, Chen TW, Chicco AJ, Carnevale EM.Advanced maternal age is associated with a decline in fertility and oocyte quality. We used novel metabolic microsensors to assess effects of mare age on single oocyte and embryo metabolic function, which has not yet been similarly investigated in mammalian species. We hypothesized that equine maternal aging affects the metabolic function of oocytes and in vitro-produced early embryos, oocyte mitochondrial DNA (mtDNA) copy number, and relative abundance of metabolites involved in energy metabolism in oocytes and cumulus cells. Samples were collected from preovulatory follicles from young (≤1...
Walsh ML, Meason-Smith C, Arnold C, Suchodolski JS, Scott EM.The eye is host to myriad bacterial, fungal, and viral organisms that likely influence ocular surface physiology in normal and diseased states. The ocular surface mycobiota of horses has not yet been described using NGS techniques. This study aimed to characterize the ocular surface fungal microbiota (mycobiota) in healthy horses in 2 environmental conditions (stalled versus pasture). Conjunctival swabs of both eyes were obtained from 7 adult stallions stabled in an open-air pavilion and 5 adult mares living on pasture. Genomic DNA was extracted from ocular surface swabs and sequenced using pr...
Laseca N, Anaya G, Peña Z, Pirosanto Y, Molina A, Demyda Peyrás S.Fertility is one of the key factors in the economic and productive success of the equine industry. Despite this, studies on the genetic causes affecting reproductive performance are scarce, especially in mares, where the genetic architecture of the reproductive traits is extremely complex. Today, with the increasing availability of new genomic methodologies for this species, we are presented with an interesting opportunity to understand the genetic basis of equine reproductive disorders. These include, among others, novel techniques for detecting chromosomal abnormalities, whose association wi...
D'Fonseca NMM, Gibson CME, Hummel I, van Doorn DA, Roelfsema E, Stout TAE, van den Broek J, de Ruijter-Villani M.Obesity has been associated with altered reproductive activity in mares, and may negatively affect fertility. To examine the influence of long-term high-energy (HE) feeding on fertility, Shetland pony mares were fed a diet containing 200% of net energy (NE) requirements during a three-year study. The incidence of hemorrhagic anovulatory follicles (HAF) and annual duration of cyclicity were compared to those in control mares receiving a maintenance diet. Day-7 embryos were flushed and transferred between donor and recipient mares from both groups; the resulting conceptuses were collected 21 day...
Ishii H, Shibuya M, Leung GN, Nozawa S, Yamashita S, Yamada M, Kushiro A, Kasashima Y, Okada J, Kawasaki K, Kijima-Suda I.GW1516 is a peroxisome proliferator-activated receptor-δ (PPAR-δ) agonist that is banned in horseracing and equestrian sports. Long-term detection and longitudinal distribution of GW1516 in the mane of a horse are reported for the first time and this hair analysis could prolong the detection window of GW1516 for doping control. Methods: Mane hairs were divided into three segments (0-7, 7-15, and >15 cm from the cut end) and completely pulverized and homogenized for analysis. The pulverized hair samples were extracted with methanol followed by further purification and the extracts were a...
Almiñana C, Rudolf Vegas A, Tekin M, Hassan M, Uzbekov R, Fröhlich T, Bollwein H, Bauersachs S.Extracellular vesicles (EVs) have been identified in the uterine fluid in different species and have been pointed as key players in the embryo-maternal dialogue, maternal recognition of pregnancy and establishment of pregnancy. However, little is known about the uterine EVs in the mare. Therefore, the present study aimed at characterizing EVs from uterine lavage of cyclic mares by comparing five EVs isolation methods and the combination of them: (1) ultracentrifugation (UC); (2) concentration of lavage volume by Centricon ultrafiltration (CE); (3) the use of CE with different washing steps (ph...
Bartholomew S, Owens SD, Ferraro GL, Carrade DD, Lara DJ, Librach FA, Borjesson DL, Galuppo LD.Stem cells derived from umbilical cord tissue (UCT) and umbilical cord blood (UCB) in human subjects and horses can be obtained in a minimally invasive fashion with successful propagation of mesenchymal stem cells (MSCs). Currently there are no detailed protocols documenting a procedure to harvest UCB and UCT safely for equine stem cell propagation. Objective: UCB and UCT could be collected without harm to mare or foal. Objective: To develop a standard and safe method for UCB and UCT collection, and prospectively to compare foal and mare health between groups of animals where tissue was and wa...
Schönbom H, Kassens A, Hopster-Iversen C, Klewitz J, Piechotta M, Martinsson G, Kißler A, Burger D, Sieme H.Pregnancy diagnostics in equine reproduction are routinely performed using transrectal ultrasonography, although it is also possible to visualize the fetus by transabdominal ultrasound examinations from the 90th day of gestation onward. We hypothesized that ultrasound examinations may stress the mare and that the gestational stage status and lactation may influence the mare's stress reaction. To investigate the stress reaction, 25 thoroughbred mares of different age, pregnancy and lactational status underwent a transrectal examination. In pregnant mares, an additional transabdominal examinatio...
McManus CJ, Fitzgerald BP.In a variety of species, short-term feed restriction leads to rapid changes in the reproductive axis and reduces serum levels of leptin. Two experiments were performed to test the hypothesis that a single day of feed restriction in aged and young mares would cause a suppression of the gonadotropins and serum leptin concentrations. The estrous cycles of 12 aged (>eight years; Exp. 1) and eight young (<five years; Exp. 2) mares were synchronized and the mares were conditioned to twice-daily meal feeding. On the seventh day after synchronization, restricted mares (n = 6 for Exp. 1; n = 4 fo...
Huber L, Giguère S, Cohen ND, Slovis NM, Berghaus L, Greiter M, Hart KA.Rhodococcus equi causes severe pneumonia in foals and is most often recognized in people as an opportunistic pathogen. Longitudinal studies examining antimicrobial-resistant R. equi from environmental samples are lacking. We hypothesized that antimicrobial-resistant R. equi would be detectable in the ground (pasture soil or stall bedding) and air at breeding farms with previous documentation of foals infected with resistant isolates, and that concentrations of resistant isolates would increase over time during the foaling season. In this prospective cohort study, ground and air samples were co...
George LA, Staniar WB, Treiber KH, Harris PA, Geor RJ.Nutritional management of animals during pregnancy can affect glucose and insulin dynamics in the resulting offspring through influences on fetal development. Additionally, high starch feeding in mature horses is associated with reduced insulin sensitivity and an increased risk for diseases such as obesity and laminitis. However, no study has yet evaluated the effect of feeding a high starch diet to pregnant mares on glucose and insulin dynamics in their offspring. Twenty late-gestation mares maintained on pasture were provided two-thirds of digestible energy requirements from isocaloric, ison...
Love CC, Brinsko SP, Rigby SL, Thompson JA, Blanchard TL, Varner DD.The relationship between seminal plasma level (0, 10, or 20%) and extender type [Kenney type (EZ-Mixin-CST) or Kenney-modified Tyrodes-KMT] to the susceptibility of sperm DNA to denaturation and sperm motility measures were investigated in cooled (5 degrees C) stallion sperm. Three ejaculates from each of three fertile stallions were collected in an artificial vagina and processed as follows: diluted one part uncentrifuged semen with four parts of extender to a final concentration of 20% seminal plasma in either CST or KMT (20% CST; 20% KMT); diluted to a final concentration of 25 million sper...
Müller-Unterberg M, Wallmann S, Distl O.The Black Forest Draught horse (BFDH) is an endangered German coldblood breed with its origin in the area of the Black Forest in South Germany. In this retrospective study, the influence of the inbreeding coefficient on foaling rates was investigated using records from ten breeding seasons. Due to the small population size of BFDH, the level of inbreeding is increasing and may have an effect on foaling rates.The data of the present study included all coverings reported for 1024 BFDH mares in the years 2001-2009. These mares were covered by 32 BFDH stallions from the State Stud Marbach. Data fr...
Witte TS, Melkus E, Walter I, Senge B, Schwab S, Aurich C, Heuwieser W.Persistent breeding-induced endometritis is ranked as the third most common medical problem in the adult mare and leads to enormous economic loss in horse breeding. In mares suffering from persistent breeding-induced endometritis, increased amounts of intrauterine (i.u.) fluid or viscous mucus in estrus or after breeding may act as a barrier for sperm and can contribute to low fertility. Current therapies of these mares aim to eliminate i.u. fluid and mucus by uterine lavage and/or administration of ecbolic drugs. Recently, i.u. administration of N-acetylcysteine (NAC) has been shown to suppor...
Beythien E, Aurich C, Wulf M, Aurich J.Seasonal changes in metabolic rate have been shown in horses and we hypothesized that this leads to the birth of smaller foals early in the year. Mares and their foals were assigned to three groups by day of foaling within the year (e.g. 1 January = day 1): Group 1 (n = 10) day 40-65, group 2 (n = 8) day 67-92, group 3 (n = 9) day 94-121. Groups did not differ with regard to parity. In foals, height at withers and body weight were determined on days 1-5 and weekly until 12 weeks of age. Chest circumference, distances fetlock to carpus, carpus to elbow, poll to nose and crown-rump lengt...
Silver M, Fowden AL.The production of uterine PGFM during different dietary states has been investigated in pregnant mares in late gestation. Arterial and uterine venous plasma concentrations of PGFM rose when food was withdrawn for 12-30 h and the V-A difference widened significantly. There was an inverse correlation between the rise in PGFM and the fall in plasma glucose during a fast, and a significant decrease in the A-V plasma glucose differences across the uterus. Plasma PGFM and free fatty acid concentrations before and during food withdrawal were also correlated but no uterine A-V difference in free fatty...
Galvão A, Skarzynski DJ, Szóstek A, Silva E, Tramontano A, Mollo A, Mateus L, Ferreira-Dias G.Knowledge on the regulation of corpus luteum (CL) function in the mare is scarce. In this study, the presence of cytokines tumor necrosis factor alpha (TNF) and interferon gamma (IFNG), and their receptors (TNFRI, TNFRII and IFNRI), was investigated in equine CL throughout the luteal phase. The effects of TNF and IFNG on secretory function and viability of luteal cells were defined in vitro. Cytokine ligands and receptors were present in steroidogenic and endothelial cells. Protein expression for TNF was greater in mid-phase and regressing CL, while TNFRI was increased in regressing CL and TNF...
Bosu WT, Van Camp SC, Miller RB, Owen RR.A five year prospective study of equine ovarian problems requiring surgical correction was undertaken at the Ontario Veterinary College. Thirty mares were studied, of which 14 had granulosa cell tumors, six were with anovulatory persistent follicular "structures", five had ovarian hemotoma, two presented ovarian hypoplasia and one each of ovarian dysgerminoma, teratoma and abscessation. The clinical signs manifested by the affected animals were varied. The affected ovaries were removed via flank or midline laparotomy or through colpotomy. Their morphology was studied and representative portion...
Alpoim-Moreira J, Fernandes C, Rebordão MR, Amaral A, Pinto-Bravo P, Bliebernicht M, Skarzynski DJ, Ferreira-Dias G.Inflammation and fibroproliferative diseases may be modulated by epigenetic changes. Therefore, we suggest that epigenetic mechanisms could be involved in equine endometrosis pathogenesis. DNA methylation is one of the methods to evaluate epigenetics, through the transcription of methyltransferases (DNMT1, DNMT3A, DNMT3B). The correlation between DNMTs and collagen (COL) transcripts was assessed for the different Kenney and Doig's (Current Therapy in Theriogenology. Philadelphia: WB Saunders; 1986) endometrium categories. Endometrial biopsies were randomly collected from cyclic mares. Histolog...
Troedsson MH, Liu IK, Ing M, Pascoe J, Thurmond M.The electrical myometrial activity of three mares with a documented increased susceptibility to chronic uterine infection (CUI) and three mares considered to be resistant to CUI was investigated. Electrodes were surgically implanted in the myometrium of the mares and electrical activity was monitored by a Grass polygraph. Oestrus was determined by transrectal ultrasonography of the reproductive tract and teasing of the mares with a stallion. Findings were confirmed by blood progesterone concentrations 35 mm was detected, the uterus was infused with a genital strain of 5 x 10(6) Streptococcus ...
Nolan MB, Schulman ML, Botha AE, Human AM, Roth R, Crampton MC, Bertschinger HJ.Commercial and regulatory limitations associated with native porcine zona pellucida (pZP) vaccines formulated with Freund's adjuvants may be overcome by developing effective recombinant ZP vaccines (reZP) and identifying alternative adjuvant formulations. A two-part preparatory study used 15 geldings and identified potentially effective alternative adjuvant formulations based on anti-pZP antibody response following treatment with pZP formulated with Addavax (AddaVax ™, Invivogen), Quil A (Quil-A® Adjuvant, Invivogen), Quil A and Poly (I:C) (HMW VacciGrade™, Invivogen), Pet Gel A (Montanid...
El-Sheikh Ali H, Legacki EL, Loux SC, Esteller-Vico A, Dini P, Scoggin KE, Conley AJ, Stanley SD, Ball BA.The current study aimed to elucidate the mechanisms underlying myometrial activation during equine placentitis related to progestogens and the progesterone receptor signaling pathways. Placentitis was induced via intracervical inoculation with Streptococcus equi ssp zooepidemicus in mares at approximately 290 days of gestation (placentitis group; n = 6) with uninoculated gestationally matched mares as controls (n = 4). Mares in the placentitis and control groups were euthanized, and myometrial samples were collected from two regions: region 1-parallel to active placentitis lesion with plac...
Rivera Del Alamo MM, Reilas T, Kindahl H, Katila T.Intrauterine glass balls are used to prevent oestrous signs in sports mares, but the mechanism of action is unknown. It has been suggested that the glass ball can mimic an embryo or act via an induced chronic uterine inflammation and absent or continuous low-grade prostaglandin (PG) release. The purpose of this study was to induce prolonged luteal function in mares using a small intrauterine device (IUD) and to study the mechanisms behind prolonged IUD-induced luteal function. A uterine swab and a biopsy specimen were obtained in early oestrus. A water-filled plastic ball, diameter 20mm and we...
Schlafer DH.During the 1960s and 1970s, the clinical value of equine endometrial histopathology was firmly established after it was shown that fertility outcome was correlated with the presence and severity of specific microscopic lesions. The objective of this paper is to summarize reports from the veterinary literature published after the mid 1980s that describe new diagnostic methods of assessing equine uterine health using material collected by endometrial biopsy.
Foote AK, Ricketts SW, Whitwell KE.Significant progress has been made in understanding and monitoring the causes of equine abortion over past decades. However, not all in utero pathology results in abortion. It has long been recognised that some in utero pathology, such as twinning or chronic placentitis, can result in the birth of live but growth-retarded foals and there is historical evidence that birth weight may influence future athletic performance. Clinical experience (e.g. from twins) and experimental studies (pony-Thoroughbred embryo transfer) have highlighted the importance of reduced functional placental area in limit...
Silva LA, Klein C, Ealy AD, Sharp DC.This work examined how the conceptus modulates endometrial tissue remodeling and vascular development prior to implantation in mares. A macroscopic uterine examination was completed at day 21 of pregnancy. In situ morphology revealed that the endometrium involved in encroachment is restricted to the dorsal endometrium immediately overlying the yolk sac. The amount of stromal area occupied by blood vessels and the number of endometrial glands were increased during early pregnancy. Endometrial histomorphometry as well as the endometrial mRNA abundance and immunolocalization of VEGF, VEGFR1, VEGF...
Steuer AE, Anderson HP, Shepherd T, Clark M, Scare JA, Gravatte HS, Nielsen MK.Horses are host to a plethora of parasites. Knowledge of the seasonality of parasite egg shedding and transmission is important for constructing parasite control programs. However, studies describing these patterns are sparse, and have largely been conducted only in the United Kingdom. This study evaluated strongylid egg shedding patterns and transmission dynamics of Strongylus vulgaris in naturally infected and untreated mares and foals through one calendar year in Kentucky, USA. The study also investigated the existence of a peri-parturient rise (PPR) in strongylid egg counts in foaling mare...
Thomson P, Pareja J, Núñez A, Santibáñez R, Castro R.Culture-independent techniques have made it possible to expand the knowledge about the composition of bacterial communities present in the healthy uterus and their role in health and disease, mainly in humans. However, in animals like mares, there is a dearth of information regarding this area. To narrow this knowledge gap, the objective of this study was to identify and characterize the composition and function of the uterine microbiome of a group of Chilean purebred mares (CPM), an equine breed with the oldest genealogical record in South America and an economical important reproductive indu...
Leal GR, Monteiro CAS, Carvalheira LR, Souza-Fabjan JMG.Simulated Physiological Oocyte Maturation (SPOM) mimics in vitro the physiological events of oocyte maturation. The system uses cAMP modulators in two steps (pre IVM and IVM) and has presented promising results that are arousing the curiosity of IVF programs in different animal species, generating several papers, adaptations, and controversies worldwide. This study systematically analyses the data in the literature on the use of SPOM and compares the outcomes to the original paper (Albuz et al. Hum. Rep., 25: 2999-3011 2010), classifying them into success or failure. The PubMed, Scopus, and ...
Kooistra LH, Ginther OJ.The effects of photoperiod on reproductive activity and hair changes in pony mares were studied in 2 experiments. In experiment I, the effect of a fixed daily photoperiod on the onset of the breeding season was studied in 36 mares from Nov 13, 1973, to June 13, 1974. The 4 treatment groups were as follows: daily photoperiod equivalent to the normal day length (control group); constant light 24 hours a day with no dark (L24:D0 group); 16-hour daily photoperiod with 8 hours of dark (L16:D8 group); and 9-hour daily photoperiod with 15 hours of dark (L9:D15 group). The intervals from beginning of ...
Macpherson ML.Equine placentitis, and resultant preterm labor, are important sources of fetal and neonatal loss. The primary cause of equine placentitis is infection of the placenta with Streptococcus equi subspecies zooepidemicus, which ascends through the caudal reproductive tract. Current treatment protocols for mares affected with placentitis are empirical. This paper reviews treatment approaches for resolving placentitis and preterm labor in both equine and non-equine species. Specific therapies reviewed include antimicrobial, anti-inflammatory, tocolytic, and progestin agents.
Stout TA, Meadows S, Allen WR.Early embryonic development in the horse is characterized by the formation of an unusual acellular glycoprotein "capsule" between the trophectoderm and the overlying zona pellucida. This structure is first detected between days 6 and 7 after ovulation and completely envelops the spherical conceptus until as late as day 23 of gestation. In the present study, a micromanipulator was used to remove the capsule from 15 embryos on day 6-7 after ovulation. None of these denuded embryos developed into ultrasonographically detectable pregnancies after surgical transfer into recipient mares whereas four...
Malaluang P, Ã…kerholm T, Nyman G, Lindahl J, Hansson I, Morrell JM.An understanding of the normal bacterial microbiota of any organ is essential to provide the background to conditions and interventions that might cause the microbiota to change. In the vagina of the mare, a change of bacterial microbiota could be induced by introduction of semen, treatment with antibiotics, discharge from an unhealthy uterus etc. Previous studies on equine vaginal bacteria are not all conducted in the same way and results are not altogether consistent. Therefore, this study was designed to provide a deeper understanding of the bacterial microbiota of the mare vagina, and poss...
Virendra A, Gulavane SU, Ahmed ZA, Reddy R, Chaudhari RJ, Gaikwad SM, Shelar RR, Ingole SD, Thorat VD, Khanam A, Khan FA.The application of high throughput technologies has enabled unravelling of unique differences between healthy mares and mares with endometritis at transcriptomic and proteomic levels. However, differences in the uterine microbiome are yet to be investigated. Objective: The present study was aimed at evaluating the differences in uterine microbiome between healthy mares and mares with endometritis. Methods: Low-volume lavage (LVL) samples were collected from the uterus of 30 mares classified into healthy (n = 15) and endometritis (n = 15) based on their reproductive history, intrauterine fl...
Bryans JT.Two herpesviruses produce diseases that affect reproductive efficiency in the horse. Equine herpesvirus 1 (EHV-1, equine rhinopneumonitis virus) is a promeinent cause of abortigenic infection as well as respiratory disease. Equine herpesvirus 3 (EHV-3, equine coital exanthema) is the cause of a benign progenital exanthema.
