Infertility in horses refers to the inability of a mare or stallion to reproduce successfully. This condition can arise from a variety of factors, including anatomical, physiological, genetic, or environmental influences. In mares, infertility may be linked to issues such as ovarian dysfunction, uterine infections, or hormonal imbalances. Stallions may experience infertility due to low sperm quality, testicular abnormalities, or reproductive tract infections. Diagnosing infertility involves a combination of physical examinations, laboratory tests, and imaging techniques to identify underlying causes. This page compiles peer-reviewed research studies and scholarly articles that explore the causes, diagnostic approaches, and management strategies for infertility in equine populations.
Pasch L, Schmidt A, King W.The use of autologous blood processing tools including platelet-rich plasma (PRP) devices is increasingly widespread in veterinary medicine. In equine reproduction, a number of studies have explored the effects of intrauterine infusion of PRP on persistent mating-induced endometritis. Artificial insemination with thawed frozen semen incites an intrauterine inflammatory response and we sought to extend the applications of intrauterine PRP to normal mares being inseminated with frozen semen. We investigated a subset of our normal breeding population to observe the clinical effects of prebreeding...
Lüttgenau J, Imboden I, Wellnitz O, Romer R, Scaravaggi I, Neves AP, Borel N, Bruckmaier RM, Janett F, Bollwein H.Persistent breeding-induced endometritis (PBIE) is a leading cause of infertility in mares. The objective of the study was to assess genital perfusion and endometrial gene expression of inflammatory cytokines in mares classified as susceptible (n = 5) or resistant (n = 5) to PBIE. Ten mares were examined daily during estrus until 6 d after hCG-induced ovulation for two estrous cycles. Twenty-four hours after application of 1500 IU hCG, 4 mL of killed (by repeated freezing in liquid nitrogen and thawing at 50 °C) deep-frozen semen or sterile saline was instilled into the uterine body an...
Ortiz-Rodríguez JM, Martín-Cano FE, Gaitskell-Phillips G, Silva A, Tapia JA, Gil MC, Redondo E, Masot J, Ortega-Ferrusola C, Peña FJ.Spermatozoa are redox-regulated cells, and stallion spermatozoa, in particular, present an intense mitochondrial activity in which large amounts of reactive oxygen species (ROS) are produced. To maintain the redox potential under physiological conditions, sophisticated mechanisms ought to be present, particularly in the mitochondria. In the present study, we investigated the role of the SLC7A11 antiporter. This antiporter exchanges intracellular glutamate for extracellular cystine. In the spermatozoa, cystine is reduced to cysteine and used for GSH synthesis. The importance of the antiporter f...
Carluccio A, Veronesi MC, Plenteda D, Mazzatenta A.The chronic degenerative endometritis (CDE) is recognised as directly related to age and infertility in the mare. In this study, the 14 days post ovulation (PO) pregnancy rate was assessed in 60 barren mares affected by CDE, submitted to platelet-rich-plasma intrauterine infusion (PRPI) 24 hours PO. Data showed a significant positive effect of PRPI on the chance to become pregnant in mares affected by Kenney I-II CDE. The overall 14 days PO pregnancy rate was 75%. Sixty-nine % of the overall pregnancies was achieved with the 1st PRPI, but an additional 31% was obtained with the 2nd PRPI at the...
Martinez MM, Costa M, Ratti C.Male-to-female sex reversal in horses is a developmental disorder in which phenotypic females have a male genetic constitution. Male-to-female sex reversal is the second most common genetic sex abnormality, after X chromosome monosomy. All male-to-female sex reversal cases studied to date have been found to be infertile. Therefore, a screening test is particularly useful in laboratories doing DNA genotyping in horses. Our laboratory has tested > 209,000 horses for parentage using a panel of microsatellite markers and the sex marker gene amelogenin (). Suspect XY sex reversal cases are rep...
Günay Uçmak Z, Kurban I, Uçmak M.Endometritis is a major cause of infertility in mares. The aim of this study is to evaluate the preovulatory follicle (POF) vascularization (A mix, A red, A blue), POF diameter, POF wall thickness, and uterine diameters in mares with or without endometritis. Ten healthy mares and 10 mares with endometritis diagnosed by the combination of transrectal palpation, ultrasonographic examination, and cytology brush were enrolled in the study. Data of the groups obtained at 2 days before the ovulation (day -2) were compared with Student's t-test. Correlations of the parameters were determined by the ...
Raudsepp T.Reproductive disorders are genetically heterogeneous and complex; available genetic tests are limited to chromosome analysis and 1 susceptibility gene. Cytogenetic analysis should be the first test to confirm or rule out chromosomal aberrations. No causative genes/mutations are known. The only available genetic test for stallion subfertility is based on a susceptibility gene FKBP6. The ongoing progress in equine genomics will improve the status of genetic testing. However, because subfertile phenotypes do not facilitate collection of large numbers of samples or pedigrees, and clinical causes o...
Caissie MD, Gartley CJ, Scholtz EL, Hewson J, Johnson R, Chenier T.Persistent breeding-induced endometritis (PBIE) is a major cause of infertility in mares. Endometrial inflammation that persists until embryonic descent ultimately results in early embryonic death. A poor endometrial biopsy grade (IIb or III) has been identified as a risk factor for PBIE. Intrauterine fluid accumulation (>2 cm in depth), pathologic endometrial edema, and elevated intrauterine neutrophil levels are all clinical features of PBIE. Commonly applied treatment options include uterine lavage and oxytocin therapy. N-acetyl cysteine (NAC), a mucolytic used to treat bacterial endome...
Szczerbal I, Nowacka-Woszuk J, Kopp-Kuhlman C, Mackowski M, Switonski M.X monosomy is the most common disorder of sex development in horses. Although cytogenetic analysis is still the gold standard in the diagnosis of equine X monosomy, novel molecular techniques are being sought to quickly and reliably detect this chromosome abnormality. Objective: The goal of this study was to evaluate the usefulness of a novel variant of the PCR technique-namely, droplet digital PCR (ddPCR)-in the detection of X monosomy in mares. Methods: A proof of concept of the usefulness of ddPCR in diagnosing an abnormal number of X chromosomes in mares. Methods: We examined an infertile ...
Domino M, Jasinski T, Kautz E, Juszczuk-Kubiak E, Ferreira-Dias G, Zabielski R, Sady M, Gajewski Z.Equine endometrosis is a multifactorial chronic degenerative condition, considered to be one of a major causes of equine infertility. The formation of periglandular fibrosis seems to be linked to chronic inflammation of the mare endometrium in a paracrine way and in a response to numerous forms of inflammatory stimuli elicit the net deposition of extracellular matrix (ECM) around the endometrial glands and stroma. We hypothesized some of these stimuli, such as monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6), and hyaluronan synthases (HASs), may share the nuclear factor-κB (NF...
Kadivar A, Shams Esfandabadi N, Dehghani Nazhvani E, Shirazi A, Ahmadi E.Protamines substitute DNA-binding histones during late spermatogenesis in sperm nucleus. Stallion sperm contains all three variants of these arginine-rich and positively charged nuclear proteins (P1, P2 and P3). Two variants of protamine-2, that is P2 and P3, constitute approximately 15% of the entire protamine content. Also, the ratio of protamine-1 to protamine-2 varies among different mammalian species, and abnormal protamine ratios and protamine content are correlated with male infertility. In this study, changes in protamine mRNA abundance for all three protamines were investigated in sta...
Witarski W, Kij B, Nowak A, Bugno-Poniewierska M.A hucul mare with reproductive abnormalities was examined during karyotype analysis. The karyotype was analysed based on evaluation of 860 metaphase plates in chromosome preparations. The use of fluorescence in situ hybridization (FISH) with an X chromosome painting probe showed premature X chromosome separation in 9.5% cases of examined chromosome spreads. In this report, we present the first identify premature centromere division (PCD) as a possible cause of abnormal X chromosome morphology in horses and as a probable cause of reproductive difficulties.
Peña FJ, O'Flaherty C, Ortiz Rodríguez JM, Martín Cano FE, Gaitskell-Phillips GL, Gil MC, Ortega Ferrusola C.Redox regulation and oxidative stress have become areas of major interest in spermatology. Alteration of redox homeostasis is recognized as a significant cause of male factor infertility and is behind the damage that spermatozoa experience after freezing and thawing or conservation in a liquid state. While for a long time, oxidative stress was just considered an overproduction of reactive oxygen species, nowadays it is considered as a consequence of redox deregulation. Many essential aspects of spermatozoa functionality are redox regulated, with reversible oxidation of thiols in cysteine resid...
Ruiz AJ, Castaneda C, Raudsepp T, Tibary A.This case report describes spermatogenic arrest and azoospermia in a stallion with a unique Y chromosome-autosome translocation. Clinical diagnosis of azoospermia was based on history of infertility and evaluation of ejaculates collected for artificial insemination. Clinical and ultrasonographic evaluation of the external and internal genitalia did not reveal any abnormalities except for smaller than normal testicular size. Azoospermia of testicular origin was confirmed by determining alkaline phosphatase concentration in semen. Histological evaluation of testicular tissue after castration con...
Długołęcka E, Tobolski D, Janowski T.Early embryonic death (EED) is one of the causes of infertility in the mare. We compared endometrial environment in 9 mares with EED and 13 mares in diestrus phase. Cotton swab (CS), cytobrush (CB) and uterine biopsy (B) samples were obtained for the cytological, bacteriological and histopathological examinations. In the first step we compared CS and CB methods to biopsy as a reference method, as B revealed the highest number of positive results in cytological and bacteriological examinations in both groups. In turn, we also compared cytological, bacteriological and histopathological findings ...
Satué K, Fazio E, Ferlazzo A, Medica P.The aim of this study was to verify the existence of possible cross-talk between biochemical contents of follicular fluid (FF) and systemic concentrations according to the follicular development of the metabolites: glucose (GLU), lactate (LACT), cholesterol (CHOL), triglycerides (TG), total bilirubin (T BIL), blood urea nitrogen (BUN), and creatinine (CREAT); enzymatic activities: gamma-glutamyl transferase (GGT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and aspartate aminotransferase (AST); electrolytes: calcium (Ca), phosphorus (P), sodium (Na), chloride (Cl), potassium (K), ...
Ortiz-Rodriguez JM, Martín-Cano FE, Ortega-Ferrusola C, Masot J, Redondo E, Gázquez A, Gil MC, Aparicio IM, Rojo-Domínguez P, Tapia JA....Oxidative stress is considered a major mechanism causing sperm damage during cryopreservation and storage, and underlies male factor infertility. Currently, oxidative stress is no longer believed to be caused only by the overproduction of reactive oxygen species, but rather by the deregulation of redox signaling and control mechanisms. With this concept in mind, here, we describe for the first time the presence of the soluble carrier family 7 member 11 (SLC7A11) antiporter, which exchanges extracellular cystine (Cyss) for intracellular glutamate, in stallion spermatozoa, as well as its impact ...
Siemieniuch MJ, Kozdrowski R, Szóstek-Mioduchowska AZ, Raś A, Nowak M.Endometritis is one of the most important causes of infertility in mares. Mares may suffer from endometritis outside the breeding season; however, pathological condition is often undiagnosed in anestrus. The aim of this study was to examine whether the secretion profiles of prostaglandin F2α (PGF2α), prostaglandin E2 (PGE2), and a metabolite of prostacyclin I2 (6-keto-PGF1α) differ in endometrial tissue cultures of heavy draft mares in anestrus with endometritis compared to those without endometritis. The endometrial biopsies were collected from 51 heavy draft mares. Inclusion criteria for ...
Poyato-Bonilla J, Anaya-Calvo G, Molina A, Valera M, Moreno-Millán M, Dorado J, Demyda-Peyrás S.Chromosomal abnormalities are a major cause of infertility and reproductive problems in equids. Nowadays, their detection is rising due to the use of new diagnostic tools based on molecular markers instead of karyotyping. Reports of this kind of genetic aberrations in domestic donkeys (Equus asinus) are extremely scarce, despite their importance in human activities. In the present study, we analysed the implementation of a short-tandem-repeat (STR)-based molecular method initially developed for horses, as a diagnostic tool to detect chromosomal abnormalities in donkeys. The frequency of five X...
Nash DM, Paddison J, Davies Morel MCG, Barnea ER.Persistent mating-induced endometritis (PMIE) is a significant cause of mare infertility hence its treatment would advance the management of susceptible mares. Preimplantation factor (PIF) is secreted by viable embryos, including human, mouse and cattle, and is essential for maternal immune-tolerance without immune-suppression by modulating inflammation. This preliminary study aimed to test whether PIF exerts inflammatory-modulating properties upon equine endometrium challenged with Escherichia coli-derived lipopolysaccharide (LPS) using endometrial explant culture. Follicular (n = 3), lutea...
Bechert U, Rohde J, Freer H, Wagner B.SpayVac is an immunocontraceptive vaccine based on porcine zona pellucida (pZP) antigens and uses a patented liposome formulation (VacciMax or DepoVax). It has delivered single-dose, long-lasting (4-10 years) immunocontraception in several species. Previous studies have demonstrated a positive correlation between levels of pZP antibodies produced and contraceptive effect; however, individual mares that were consistently infertile did not necessarily have the highest antibody titers. The objective of this study was to identify potential differences in specific immunoglobulin G (IgG) isotype res...
Pye J, Clulow J, Adkins A.To describe the laparoscopic transection of restrictive bands of the mesosalpinx as a useful adjunct to the topical application of prostaglandin E to treat mares with suspected uterine tubal blockage. Methods: A standard left flank laparoscopic approach was made to the abdomen using three laparoscopic portals. If restrictive bands of the mesosalpinx were observed traversing the uterine tube perpendicularly, they were carefully transected and 1 mg of prostaglandin E was then applied to the external surface of the uterine tube. Skin incisions were closed with surgical staples and the procedure...
Ferrer MS, Miller LMJ.Antisperm antibodies (ASAs) have been associated with infertility in stallions. The objectives of this study were to investigate the frequency of ASA-positive semen samples in satisfactory and non-satisfactory breeder stallions, the association between ASA binding and semen quality, and factors that may affect the diagnosis. Breeding soundness examinations were performed in 21 stallions and the percentage of IgG- and IgA-bound spermatozoa was evaluated using flow cytometry. Median IgG and IgA binding did not differ between the first and second ejaculates. The percentage of IgA-bound spermatozo...
Pozor M, Conley AJ, Roser JF, Nolin M, Zambrano GL, Runyon SP, Kelleman AA, Macpherson ML.Recently, anti-Müllerian hormone (AMH) was validated as a reliable marker of testicular damage caused by various chemotherapy drugs in humans and in mice. In horses, the reference values of AMH concentrations in normal stallions, during different seasons of a year, have been recently reported. However, this hormone was not evaluated in subfertile or infertile stallions with testicular damage. Therefore, the objective of this study was to investigate the effects of experimentally induced testicular degeneration on the concentration of AMH in stallions. Severe but transient testicular degenerat...
Davis KA, Klohonatz KM, Mora DSO, Twenter HM, Graham PE, Pinedo P, Eckery DC, Bruemmer JE.Currently there is no contraceptive vaccine that can cause permanent sterility in mares. This study investigates the effect of vaccination against oocyte-specific growth factors, Bone Morphogenetic Protein 15 (BMP-15) and Growth Differentiation Factor 9 (GDF-9), on ovarian function of mares. It was hypothesized that immunization against these growth factors would prevent ovulation and/or accelerate depletion of the oocyte reserve. For this study, 30 mares were randomly assigned to three groups (n = 10/group) and vaccinated with BMP-15 or GDF-9 peptides conjugated to KLH and adjuvant, or a ...
Inoue Y, Sekiguchi M.Therapeutic techniques for oviductal obstruction in the mare are limited. Nonsurgical and retrograde flushing may be an attractive alternative to current treatment methods for oviductal blockage. Objective: To evaluate hysteroscopic selective hydrotubation as a treatment option for presumptive equine oviductal blockage. Methods: Retrospective case series. Methods: A quantity of 10 mL of saline was flushed through the oviducts in 28 standing sedated mares, which had reproductive histories of unexplained subfertility, by inserting a catheter into the uterotubal junction under endoscopic guidance...
Sikora M, Nowak M, Racheniuk H, Wojtysiak K, Kozdrowski R.Endometritis and endometrosis have been and still are the major reasons for infertility in mares. The diagnosis of endometritis can be based on cytology and microbiology, but endometrial biopsy is still the only way to diagnose endometrosis in the mare. Our study attempted to determine if a single biopsy using his-topathology and immunohistochemistry is sufficient to ascertain reasons for infertility in Icelandic mares. The objectives of this study were to examine the relationship between deviations in endometrial biopsies in terms of prostaglandin-endoperoxide synthase-2 (PTGS-2) and fibronec...
Franciosi F, Tessaro I, Dalbies-Tran R, Douet C, Reigner F, Deleuze S, Papillier P, Miclea I, Lodde V, Luciano AM, Goudet G.The field of assisted reproduction has been developed to treat infertility in women, companion animals, and endangered species. In the horse, assisted reproduction also allows for the production of embryos from high performers without interrupting their sports career and contributes to an increase in the number of foals from mares of high genetic value. The present manuscript describes the procedures used for collecting immature and mature oocytes from horse ovaries using ovum pick-up (OPU). These oocytes were then used to investigate the incidence of aneuploidy by adapting a protocol previous...
Schnobrich MR, Gordon DL, Scoggin CF, Bradecamp EA, Canisso IF.Urine pooling, as a persistent condition, is a cause of infertility in mares due to endometrial inflammation and sperm toxicity. Identification of urometra can be challenging in mares presenting with the condition intermittently, or when urine flows into the uterus but is undetectable in the vagina. Currently, there are no reported objective methods to confirm the clinical diagnosis of urine contamination in intrauterine-fluid accumulations. Since creatinine is present in high concentrations in urine and does not diffuse across cell membranes, creatinine concentration should be increased in ma...
Chromosomal abnormalities in the sex chromosome pair (ECAX and ECAY) are widely associated with reproductive problems in horses. However, a large proportion of these abnormalities remains undiagnosed due to the lack of an affordable diagnostic tool that allows for avoiding karyotyping tests. Hereby, we developed an STR (single-tandem-repeat)-based molecular method to determine the presence of the main sex chromosomal abnormalities in horses in a fast, cheap and reliable way. The frequency of five ECAX-linked (LEX026, LEX003, TKY38, TKY270 and UCDEQ502) and two ECAY-linked (EcaYH12 and SRY) mar...
Lear TL, McGee RB.Abnormalities of sexual development causing infertility in horses have been investigated since the early 1970's. Conventional cytogenetic analysis by karyotyping has been the primary tool used to investigate these horses. Abnormalities have a broad range, from a phenotypically normal mare with gonadal dysgenesis to a horse with ambiguous external genitalia and internal male and female organs. Cytogenetic analysis can determine genetic sex but cannot identify mutations or deletions of genes involved in the sex determination pathway. Molecular technologies have been developed to confirm cytogene...
Gamboa S, Ramalho-Santos J.Proteins implicated in the "SNARE hypothesis" for membrane fusion have been characterized in the acrosome of several mammalian species, and a functional role for these proteins during the acrosome reaction has been proposed. We have investigated the presence of SNAREs in equine sperm, using semen samples obtained from stallions with varying fertility. Immunocytochemical analysis revealed that members of different SNARE families can be detected on the acrosome of equine sperm, notably in the acrosomal cap and equatorial segment. These proteins include the t-SNARE syntaxin, the v-SNARE synaptobr...
Lear TL, Lundquist J, Zent WW, Fishback WD, Clark A.Repeated early embryonic loss (REEL) represents a considerable economic loss to the horse industry. Mares that experience REEL may be overlooked as potential carriers of a chromosome abnormality. Here we report three different autosomal translocations in Thoroughbred mares presented for chromosome analysis because of REEL. The karyotypes were 64,XX,t(1;21), 64,XX,t(16;22), and 64,XX,t(4;13), respectively. In order to confirm the chromosomes involved in the translocations, to map the breakpoints, and to determine if the translocations were reciprocal, genes surrounding the breakpoints were iden...
Demyda-Peyrás S, Anaya G, Bugno-Poniewierska M, Pawlina K, Membrillo A, Valera M, Moreno-Millán M.Sex chromosome aberrations are known to cause congenital abnormalities and unexplained infertility in horses. Most of these anomalies remain undiagnosed because of the complexity of the horse karyotype and the lack of specialized laboratories that can perform such diagnoses. On the other hand, the utilization of microsatellite markers is a technique widely spread in horse breeding, mostly because of their usage in parentage tests. We studied the usage of a novel combination of diagnostic approaches in the evaluation of a very uncommon case of chromosomal abnormalities in a Spanish purebred col...
Ortiz-Rodriguez JM, Martín-Cano FE, Ortega-Ferrusola C, Masot J, Redondo E, Gázquez A, Gil MC, Aparicio IM, Rojo-Domínguez P, Tapia JA....Oxidative stress is considered a major mechanism causing sperm damage during cryopreservation and storage, and underlies male factor infertility. Currently, oxidative stress is no longer believed to be caused only by the overproduction of reactive oxygen species, but rather by the deregulation of redox signaling and control mechanisms. With this concept in mind, here, we describe for the first time the presence of the soluble carrier family 7 member 11 (SLC7A11) antiporter, which exchanges extracellular cystine (Cyss) for intracellular glutamate, in stallion spermatozoa, as well as its impact ...
Ricketts SW.The author describes a technique for obtaining endometrail biopsy specimens from mares. the noraml cyclincal histology of the endometrium and anarbitarry classification histology of the endometrium and an arbitarary classification of the histopathology seen in endometrial biopsy speciemens. Previous literature on the subject is cited. Results of endometrial biopsies taken by the author from 134 barren mares, with histories of subfertility are descirbed and classified. The use of the technique and the interpretationof its find ings in relation to reproductive performance is discussed.
Buczkowska J, Kozdrowski R, Nowak M, Raś A, Mrowiec J.Equine endometrosis is a multifactorial disease considered to be a one of the most important causes of equine infertility, especially in older mares. This article reviews the current knowledge of equine endometrosis: pathogenesis, diagnosis, and optional treatment. Also describes the histomorphological and immunohistochemical characterization of endometrosis as well as potential etiological factors which may influence disease progression. Unfortunately, the etiology and pathogenesis of endometrosis still remains unclear, and consequently no effective treatment has been proposed so far. Therefo...
Leme DP, Papa FO.Fifteen stallions of different breeds, age 3-11 years, had their right testicles evaluated by fine needle aspiration cytology (FNAC). Cytological analysis showed the following spermatogenic cell types: spermatogonia (1.6% +/- 1.1); spermatocyte I (3.4% +/- 2.2); spermatocyte II (0.8% +/- 0.7); early spermatids (25.5% +/- 9.5); late spermatids (37.0% +/- 9.3). Spermatozoal numbers were expressed as the spermatic index (SI = 31.5% +/- 8.5) and Sertoli cells were expressed as the Sertoli cell index (SEI = 20.9% +/- 17.0) (means +/- s.d). Identification of cell types was relatively easy and no imm...
Allen WR, Wilsher S, Morris L, Crowhurst JS, Hillyer MH, Neal HN.Mares are occasionally encountered that consistently fail to conceive when inseminated, naturally or artificially, with fertile stallion semen in the absence of any identifiable pathology of either the structure or function of their reproductive tract. Objective: Temporary blockage of the oviducts by accumulations of naturally occurring oviducal masses may be preventing oviducal transport of the embryo to the uterus. Methods: Mares, with known reproductive histories, that had exhibited inexplicable failure of conception were treated by laparoscopically guided administration of PGE2-laced triac...
Ransom JI, Hobbs NT, Bruemmer J.Abiotic inputs such as photoperiod and temperature can regulate reproductive cyclicity in many species. When humans perturb this process by intervening in reproductive cycles, the ecological consequences may be profound. Trophic mismatches between birth pulse and resources in wildlife species may cascade toward decreased survival and threaten the viability of small populations. We followed feral horses (Equus caballus) in three populations for a longitudinal study of the transient immunocontraceptive porcine zona pellucida (PZP), and found that repeated vaccinations extended the duration of in...
Kilgenstein HJ, Schöniger S, Schoon D, Schoon HA.After their retirement from sports, performance mares often show a poor breeding success. The objective of this study was the microscopic evaluation of endometrial biopsies of retired sports mares (n = 189) to search for alterations that may explain subfertility. Mares of this study aged 3-23 years showed endometritis (30%) and endometrosis (77%); mild forms predominated. In regard to those mares biopsied during the breeding season (n = 99), 50% had glandular differentiation disorders, i.e. glandular inactivity (8%) or irregular glandular differentiation (42%). Compared to literature d...
Roser JF, Hughes JP.Seasonal effects on hormonal and seminal parameters in subfertile stallions have not been well documented and could provide information that is needed to understand the underlying endocrine mechanisms associated with testicular dysfunction. Such information may be useful in developing diagnostic tools to identify those stallions who are candidates for treatment. This investigation characterizes and compares the effects of season on endocrine function and seminal quality in fertile and subfertile stallions. Eight fertile and six subfertile stallions between the ages of 5 and 18 years were injec...
McCoy DJ.Both ovaries in a 10-year-old American Saddle Horse mare were determined to be larger than normal. The mare had problems with infertility during the preceding 3 years. Clinical evaluation revealed that the mare was polyuric, polydypsic, hyperinsulinemic, and hyperglycemic, and had reduced tolerance to exogenous glucose. Bilateral granulosa cell tumors were identified on histologic examination of the ovaries. The precise mechanism for the secondary diabetes mellitus was not determined; however, the cause was suspected to be a result of the synthesis and release of a hormonal substance by the tu...
Schoon HA, Wiegandt I, Schoon D, Aupperle H, Bartmann CP.Different types of endometrial maldifferentiation were investigated by histopathological (haematoxylin-eosin (HE), periodic acid Schiff-alcian blue and picro-sirius red staining) and immunohistological (oestrogen and progesterone receptors, Ki-67 antigen, intermediate filaments and laminin) analysis of endometrial biopsy specimens from mares (n=34), most of which had been barren for at least 1 year. Two major features were observed: (i) unequal differentiation, in which two functional stages are visible within a single biopsy sample: areas which are differentiated in accordance with the stage ...
Causey RC.Uterine infections are a major cause of infertility, but the role of mucus in equine uterine defense is not well understood. Mucociliary currents play an important role in protecting mucous membranes, including the upper and lower respiratory tracts of mammals, and are required for feeding and oxygenation of many aquatic invertebrates. Although phagocytosis has long been considered the first line of uterine defense in the mare, there are concerns about its efficacy in the uterine lumen. Additional local defenses, such as mucociliary currents, have therefore been proposed. The uterine epitheliu...
Chromosomal abnormalities in the sex chromosome pair (ECAX and ECAY) are widely associated with reproductive problems in horses. However, a large proportion of these abnormalities remains undiagnosed due to the lack of an affordable diagnostic tool that allows for avoiding karyotyping tests. Hereby, we developed an STR (single-tandem-repeat)-based molecular method to determine the presence of the main sex chromosomal abnormalities in horses in a fast, cheap and reliable way. The frequency of five ECAX-linked (LEX026, LEX003, TKY38, TKY270 and UCDEQ502) and two ECAY-linked (EcaYH12 and SRY) mar...
Harris IT, Maddock C, Farnworth M, Nankervis K, Perrett J, Pyatt AZ, Blanchard RN.Adverse trends in reproductive function are a concern in humans, companion, livestock, and wildlife species. This study indicates that equine populations are at risk of a comparable decline in sperm progressive motility. There is increasing evidence reporting geographically sensitive adverse trends in human semen quality, with parallel trends observed in the dog sentinel. Despite significant economic and welfare complications associated with poor testicular function, trends in current equine populations are undetermined. Given the predictive value of sperm progressive motility (PMOT) in male f...
Schofield WA.The goal of this review is to provide evidence supporting the physiologic basis for the use of acupuncture as a treatment in equine reproduction, and to discuss current uses of acupuncture for the treatment of anestrus, urine pooling, uterine infection and/or fluid, infertility, maintenance of pregnancy, cryptorchidism, musculoskeletal pain, and poor libido in stallions. The benefits achieved through acupuncture treatment are thought to be a result of hormonal regulation, altered smooth muscle motility, and general stress and/or pain relief from musculoskeletal or environmental conditions.
Rantala M, Attia S, Koukila-Kähkölä P, de Hoog S, Anttila M, Katila T.We present an unusual equine endometritis case associated with Cladophialophora bantiana in a 15-year-old mare. The mare displayed infertility and uterine fluid accumulation with numerous black, hairy granules. Microscopically, the fluid revealed numerous septate, dark fungal hyphae and conidia in chains. Culture yielded C. bantiana (CBS 138271); the species was confirmed by internal transcribed spacer (ITS) sequencing. Treatment was unsuccessful. C. bantiana causes cerebral phaeohyphomycosis in humans, while animal cases are rare. Animal cases are reviewed.
Nash DM, Paddison J, Davies Morel MCG, Barnea ER.Persistent mating-induced endometritis (PMIE) is a significant cause of mare infertility hence its treatment would advance the management of susceptible mares. Preimplantation factor (PIF) is secreted by viable embryos, including human, mouse and cattle, and is essential for maternal immune-tolerance without immune-suppression by modulating inflammation. This preliminary study aimed to test whether PIF exerts inflammatory-modulating properties upon equine endometrium challenged with Escherichia coli-derived lipopolysaccharide (LPS) using endometrial explant culture. Follicular (n = 3), lutea...
Pirosanto Y, Laseca N, Valera M, Molina A, Moreno-Millán M, Bugno-Poniewierska M, Ross P, Azor P, Demyda-Peyrás S.Chromosomal abnormalities are a common cause of infertility in horses. However, they are difficult to detect using automated methods. Here, we propose a simple methodology based on single nucleotide polymorphism (SNP)-array data that allows us to detect the main chromosomal abnormalities in horses in a single procedure. As proof of concept, we were able to detect chromosomal abnormalities in 33 out of 268 individuals, including monosomies, chimerisms, and male and female sex-reversions, by analyzing the raw signal intensity produced by an SNP array-based genotyping platform. We also demonstrat...
Yaralioglu-Gurgoze S, Cetin H, Cen O, Yilmaz S, Atli MO.Endometritis is an important factor in infertility. Free radicals play an important role in endometritis and we have investigated their possible role and scavenging systems in endometritis in purebred Arabian mares. The plasma concentration of malondialdehyde (MDA) and erythrocyte glutathione peroxidase (GPx) activity were compared in healthy mares and in mares with endometritis. The level of MDA was significantly increased while GPx activity was decreased in the mares with endometritis. Our findings support the notion that GPx is consumed by increased lipid peroxidation in purebred Arabian ma...
Evans TJ, Miller MA, Ganjam VK, Niswender KD, Ellersieck MR, Krause WJ, Youngquist RS.To develop an objective, quantifiable assay for endometrial periglandular fibrosis (EPF) and correlate assay results with histologic and ultrastructural changes in equine endometrial biopsy specimens. Methods: Endometrial biopsy specimens from 70 mares from 3 to 27 years old in estrus. Methods: In a double-blinded study design, endometrial biopsy specimens were graded histologically (modified Kenney classification) for EPF and inflammation. Endometrial periglandular collagen volume fraction (%EPCVF) was determined by light microscopic image analysis of picrosirius red-stained sections. Specime...
Stewart BL, Roser JF.The nature of the relationship between inhibin and reproductive function in the stallion is yet to be elucidated. Blood and testes from 51 light horse stallions ranging in age from 2 mo to 25 years were collected during the breeding and nonbreeding seasons to study the effects of testicular maturation, aging, season, and fertility status on peripheral and intratesticular concentrations of Ir inhibin and other reproductive hormones. Of the 51 stallions, 12 age-matched stallions (6 fertile, 3 subfertile, and 3 infertile) were used in the fertility study. Blood samples were taken before castratio...
Pujar S, Meyers-Wallen VN.Inherited disorders of sexual development (DSD) cause sterility and infertility in horses. Mutations causing such disorders have been identified in other mammals, but there is little information on the molecular causes in horses. While the equine genome sequence has made it possible to identify candidate genes, additional tools are needed to routinely screen them for causative mutations. In this study, we designed a screening panel of polymerase chain reaction primer pairs for 15 equine genes. These are the candidate genes for testicular or ovotesticular XX DSD and XY DSD, the latter of which ...
Raudsepp T.Reproductive disorders are genetically heterogeneous and complex; available genetic tests are limited to chromosome analysis and 1 susceptibility gene. Cytogenetic analysis should be the first test to confirm or rule out chromosomal aberrations. No causative genes/mutations are known. The only available genetic test for stallion subfertility is based on a susceptibility gene FKBP6. The ongoing progress in equine genomics will improve the status of genetic testing. However, because subfertile phenotypes do not facilitate collection of large numbers of samples or pedigrees, and clinical causes o...
Davis KA, Klohonatz KM, Mora DSO, Twenter HM, Graham PE, Pinedo P, Eckery DC, Bruemmer JE.Currently there is no contraceptive vaccine that can cause permanent sterility in mares. This study investigates the effect of vaccination against oocyte-specific growth factors, Bone Morphogenetic Protein 15 (BMP-15) and Growth Differentiation Factor 9 (GDF-9), on ovarian function of mares. It was hypothesized that immunization against these growth factors would prevent ovulation and/or accelerate depletion of the oocyte reserve. For this study, 30 mares were randomly assigned to three groups (n = 10/group) and vaccinated with BMP-15 or GDF-9 peptides conjugated to KLH and adjuvant, or a ...
Ginther OJ.One of the most profound theriogenology applications of transrectal diagnostic ultrasonography in mares involves the imaging of ovarian follicles and corpora lutea. The resolving capabilities (frequency) and quality of the scanner directly affect the minimal size of a structure that can be imaged and the quality of the image. High-frequency scanners (5 or 7.5 MHz) of good quality can image a 2-mm follicle and the corpus luteum throughout its functional life. A low-frequency scanner (3 or 3.5 MHz) can image a 6-mm follicle and the corpus luteum for several days after ovulation. Equine follicles...
