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.
Carvalho IB, Branco S, Laranjo M, Queiroga MC, Bettencourt E.Uterine health is paramount to fertility in broodmares and for the success of a breeding project, and the Lusitano breed is no exception. This study aimed to characterize the mare uterine microbiota using practical clinical evaluation methods. Mares were examined by transrectal palpation and ultrasonography, followed by the collection of samples by one of three different techniques: uterine lavage, biopsy, or swab. The results of cytology, histology, microbiology, and antimicrobial susceptibility testing were recorded, and statistical analyses were performed. Inflammation was present in 42.2% ...
Changes in the global climate pose a severe threat to human and animal welfare and productivity. Total proteins (TP), globulins (GLOB), albumins (ALB), alkaline phosphatase (ALP), creatine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), blood urea nitrogen (BUN), γ-glutamyl transferase (GGT), and creatinine (CREA) were evaluated during a three-year monitoring period (2021-23) on 16 Thoroughbred retired mares from the regional Golkoy Breeding Farm in Kastamonu- Turkey. The following thermal and hygrometric parameters were gathered: ambient temperature (AT), relative...
There are four genotypes of ovine papillomaviruses (OaPVs): OaPV1, OaPV2, and OaPV4, which are ovine delta papillomaviruses responsible for epithelial and mesenchymal cell infections, and OaPV3, an epitheliotropic Dyokappapapillomavirus associated with cutaneous tumors in sheep, including squamous cell carcinoma. Vaginal swabs of healthy mares were evaluated for the presence of PVs to investigate whether the vaginal virobiota of asymptomatic mares harbored OaPVs. High-performance digital droplet polymerase chain reaction (ddPCR) was used to quantitatively detect OaPV types 1-4 DNA in 94 vagina...
Wagner JCP, Edwards M, Trivedi S, Minter LJ, Ange-van Heugten K.Microquantity laboratory procedures (<5 mL) are often used to analyze milk from non-bovid or less common species due to limited available samples and small sample sizes, unlike the large quantities of milk needed for macroquantity (~20 mL) assays standard in the commercial dairy industry. To better understand microquantity milk laboratory analyses, quarter horse () milk from North Carolina State University (females = 4, n = 43) and California Polytechnic State University (females = 4, n = 42) equine centers was compared to investigate differences in macronutrient composition from 4 to 130 d...
Cuervo-Arango J, Sala-Ayala L, Márquez-Moya A, Martínez-Boví R.The objective of this study was to determine the effect of two aspiration pressures (75 vs. 150 mmHg), the follicle flushing method (injection pump controlled by a foot pedal vs. a plastic syringe) and the twisting of the OPU needle on oocyte recovery and in vitro embryo production. OPU data from a total of 104 warmblood sport mares belonging to a commercial OPU-ICSI program were collected as part of a prospective study split into three experiments. Each mare was used only once for OPU. In Experiment 1, the mares' follicles were aspirated using either a high aspiration pressure (flow rate of 1...
Khan IU, Khairullah AR, Khan AY, Rehman AU, Mustofa I.This review explores advanced strategies for enhancing fertility and optimizing reproductive outcomes in equine breeding programs. Horses, being seasonal breeders, present unique reproductive challenges influenced by environmental and physiological factors such as photoperiods, hormone cycles, and aging. Key approaches discussed include hormonal therapies, artificial light manipulation, and nutritional supplementation to improve ovulation and conception rates during the breeding season. Specific hormones such as gonadotropin-releasing hormone analogs, equine follicle-stimulating hormone, and p...
The increasing interest in the study of spontaneous (SY) and contagious yawning (CY) was so far focused on several taxa, especially primates. Here, we focused on SY and CY in horses, a suitable species due to their complex social dynamics that has been largely overlooked in research on these phenomena. By analyzing videos of 48 horses on pasture, we identified 2 yawning morphologies: Covered ( ) and Uncovered Teeth ( ). Using EquiFACS, we quantitatively demonstrated that and differ in terms of muscle recruitment. Moreover, we provide the first evidence for the presence of CY by comparing 2...
Sielhorst J, Koether K, Volkmann N, Blanco M, Vicioso R, Baade S, Kemper N, de Mestre AM, Sieme H.Little is known about the incidence and outcome of high-risk pregnancies in equine practice and clinical studies on spontaneous occurring placentitis cases and treatments are missing. Therefore, the aims of this retrospective field study were to (1) describe the incidence and severity of ultrasonographic assessed placental abnormalities (UPA) in 4,192 pregnancies on a large commercial warmblood stud farm in 2017 - 2019 and (2) characterize these UPA cases and their pregnancy outcome. UPA severity (Placental abnormality score (PSc) 1-3; low to high), nine treatment regimens (TM1-9) used in UPA ...
Satué K, Fazio E, Damiá E, Barbiera G, Medica P, Cravana C.Androgens are produced in both sexes. In females produced by the adrenal gland and the ovaries they play a crucial role in regulating ovarian function, estrogen synthesis and follicular growth. Age leads to a reduction in androgen concentrations, although, at present, these mechanisms are not elucidated in mares. The objective of this study was to evaluate the concentrations of testosterone (T), androstenedione (A) and dehydroepiandrosterone (DHEA) in mares of different ages. Blood samples were drawn from seventy cyclic Spanish Purebred mares belonging to five age groups: 3-5 years, 6-9 year...
Rapezzano G, Marcatili M, Stephenson R, Pereira R, Hallowell G, Duz M.Peritoneal fluid lactate concentration is an important diagnostic tool in horses with abdominal pain. Information on peritoneal lactate concentrations is lacking following parturition in the mare. To compare blood and peritoneal lactate concentrations in a population of mares within 36 h post-partum, report a normal reference range and identify any impact of retained foetal membranes (RFMs). This is a retrospective study evaluating healthy mares from which blood and peritoneal samples had been obtained within 36 h of parturition. Exclusion criteria included signs of abdominal pain within thi...
Artman JL, Wesolowski LT, Semanchik PL, Isles JK, Norton SA, White-Springer SH.We aimed to test the hypothesis that repeated muscle collections would impact mitochondrial function, antioxidant status, and markers of inflammation and muscle damage. Twenty-six horses (8 geldings, 18 mares; mean±SD 9.5±3.5 y) had gluteus medius muscle biopsy samples collected at: 0 and 24h (n=7); 0 and 6h (n=6); 0, 6, and 12h (n=7); or 0, 6, 12, and 24h (n=6). Blood was collected from all horses every 6h for 72h, starting 24h prior to the 0h muscle collection. Data were analyzed using mixed linear models. Muscle integrative (per mg tissue) electron transfer capacity of complex II decrease...
Fonte JS, Alonso MA, Junior MPM, Gonçalves MA, Pontes JH, Bordignon V, Fleury PDC, Fernandes CB.This retrospective study aimed at identifying factors that contribute to the success of equine in vitro embryo production by intracytoplasmic sperm injection (ICSI). A total of 7993 ovum pick-up (OPU) sessions were performed, totaling 2540 donor mares and semen from 396 stallions. Oocytes were aspirated at multiple sites in Brazil and were sent to the laboratory, within 6 h from OPU, in pre-maturation medium where they were in vitro matured (IVM) followed by ICSI and in vitro embryo culture for 7-8 days. The number of recovered oocytes, matured oocytes, cleaved embryos and blastocysts were us...
Guerrero JLS, Brito PHS, Ferreira MA, Arantes JA, Rusch E, Oliveira BVDS, Velasco-Bolaños J, Carregaro AB, Dória RGS.The prevalence of gastric disorders in high-performance horses, especially gastric ulceration, ranges from 50 to 90%. These pathological conditions have negative impacts on athletic performance and health. This study was designed to evaluate changes in gastric pH during a 24 h period and to compare gastrin concentrations at different time points in horses undergoing general inhalation anesthesia and dorsal recumbency. Twenty-two mixed-breed mares weighing 400 ± 50 kg and aged 8 ± 2 years were used. Of these, eight were fasted for 8 h and submitted to 90 min of general inhalation anesthesia i...
Zhang X, Mai Z, Gao Y, Zhao X, Zhang Y.Endometritis is a common condition in mares that causes significant economic loss. Lacking obvious clinical signs, the clinical diagnosis of endometritis in mares relies on case-by-case clinical examinations, which can be particularly inefficient in large-scale farms. Therefore, the identification of potential biomarkers can serve as a non-invasive and efficient screening technique for endometritis in mares. Objective: To compare the blood proteome between fertile mares and mares with endometritis to identify biomarkers potentially associated with the development of endometritis and validate t...
Morris L, Harteveld R, Gibb Z.Insemination of mares with frozen-thawed spermatozoa requires intensive management and results in 40%-60% per cycle pregnancy rates. Objective: To determine if satisfactory fertility is possible for frozen-thawed semen after processing it through a microfluidic device, followed by storage at 17°C for up to 24 h before fixed-time insemination. Methods: Uncontrolled field trials. Methods: A pilot study evaluated the motility of frozen-thawed spermatozoa after centrifugation and storage (17°C) in two different media for up to 48 h. Subsequently, the motility of frozen-thawed semen processed...
Pires LSA, Abrahão C, Dias de Castro LL, Hammerschmidt J, Antunes J, Molento CFM, Molento MB.Horse welfare assessment (HWA) does not account for individual or herd parasite infection. This study investigated the connection between HWA and individual parasite fecal egg count (FEC) in 90 Thoroughbred horses. All horses were naturally infected with gastrointestinal parasites and were evaluated for individual welfare indicators and FEC monthly, for 12 months. Horses were divided into three groups of 30 mares, 30 foals aged between 13 and 16 months (G2013), and 30 foals aged between two months and one year (G2014). A horse welfare protocol was developed and 1024 assessments were carried ou...
Pérez-Nogués M, Manso-Díaz G, Spirito M, López-Sanromán J.Subchondral cystic lesions (SCL) in the medial femoral condyle are a usual finding in Thoroughbred survey and auction repository radiographs. Several treatments with different outcomes have been studied over the years to improve soundness and racing prognosis. Our objective was to report the racing prognosis in Thoroughbred yearlings intended for racing that were diagnosed with SCL in the medial femoral condyle and were treated using four current and different techniques: intralesional injection of corticosteroids, SCL debridement through the joint with a drill bit, translesional cortical scre...
Artificial insemination with cooled-shipped semen is the primary method used in the equine breeding industry; yet, sperm quality and fertility can be suboptimal for some stallions when standard techniques are used. Therefore, there is a critical need to develop alternative approaches for these stallions. Objective: To assess sperm quality parameters and fertility of cooled-stored stallion semen processed by SpermFilter® or centrifugation and resuspended in three extenders. Methods: Controlled and field study. Methods: In Experiment 1, semen was collected from 21 stallions classified as having...
Podico G, Bittar JH, Loux SC, Souza FF, Canisso IF.Anecdotal experience suggests horse mares have less post-breeding inflammation and better fertility when bred with donkeys. This study aimed to compare the post-breeding inflammatory response of mares exposed to donkey and horse semen and seminal plasma and evaluate the proteome and metabolome of donkey and horse sperm and seminal plasma. Uterine edema, intrauterine fluid accumulation, PMNs on cytology, and concentrations of progesterone, and pro- and anti-inflammatory cytokines (IL1, IL1, IL4, IL6, CXCL8, IL10) concentrations were assessed pre-and post-infusion of semen and seminal plas...
Retamar GC, Bustos CP, Guillemi EC, Becú T, Ivanissevich A, Mesplet M, Muñoz AJ.Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) is a mucosal commensal of the lower genital tract in horses and is the most isolated bacterium causing endometritis in mares. The aim of this study was to determine the molecular diversity of S. zooepidemicus obtained from endometritis in mares in Buenos Aires province, Argentina. Thirty isolates obtained from the uterus of mares in 2005 and 2017 were studied. The MLST scheme was applied to identify the Argentinian genotypes and the clonal relationships and patterns of evolutionary descent were identified using the eBURST algorithm - g...
Alkhadrawy JMH, Aboelmaaty AM, Abou-Ahmed MM, Ghallab AM.Mares are the only companion animals simulating women in the large diameter of their follicles. Horses start reproduction at the age of three years, and some of them live for >30 years, so aging influences their reproductive capacity. Mares are sensitive to summer heat stress as they can sweat like humans. Unassigned: The current work aimed to study the effects of age (young versus senile), season (cold versus hot), and the hormonal treatments during embryo collection on the dominant and subordinate follicular dynamics and hemodynamics and circulating ovarian hormones in embryo donor mares ...
Catandi GD, Fresa KJ, Cheng MH, Whitcomb LA, Broeckling CD, Chen TW, Chicco AJ, Carnevale EM.Obesity is a growing concern in human and equine populations, predisposing to metabolic pathologies and reproductive disturbances. Cellular lipid accumulation and mitochondrial dysfunction play an important role in the pathologic consequences of obesity, which may be mitigated by dietary interventions targeting these processes. We hypothesized that obesity in the mare promotes follicular lipid accumulation and altered mitochondrial function of oocytes and granulosa cells, potentially contributing to impaired fertility in this population. We also predicted that these effects could be mitigated ...
Klecel W, Kloch M, Wojciechowska M, Gajewska M, Martyniuk E.With a history tracing back to at least the 18th century and a substantial global influence on various breeds, Polish Arabian horse population is of paramount importance for both breeders and conservationists. However, its genetic makeup and the population dynamics are still not well understood. This study presents an analysis of the modern Polish Arabian horse population using pedigree data, focusing on the breed's genetic diversity and population structure. Our analysis encompassed 1 498 individuals defined as the reference population (RP) and their 11 065 ancestors, which resulted in the ...
Determination of morphological and biochemical blood indices facilitates assessment of the health and welfare of horses, their nutrient demand, the effects of training already undertaken, and the horses' suitability for exercise. Identification of the season-dependent components and the effects of sex and exercise on changes in frequently referenced haematological and biochemical parameters was the main goal of the current study. Unassigned: The blood morphology of 21 healthy adult Shetland ponies (11 mares and 10 stallions) aged 6.5 ± 1.4 years from the central Pomeranian region in Poland wa...
Pusterla N, Lawton K, Barnum S.Adult horses are susceptible to equine coronavirus (ECoV) and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), although, only ECoV has been linked to clinical disease. Little information is available regarding the seroprevalence against ECoV and SARS-CoV-2 in adult healthy horses. The goal of the present study was to determine the seroprevalence against two coronaviruses known to infect horses using convenience samples collected from horses recently imported from Europe to the United States from 2019 to 2023. A total of 385 banked serum samples were tested against ECoV and SARS-Co...
Cardiovascular changes have been reported in late pregnancy in mares. However, there are no data on changes in peripheral blood flow. Doppler ultrasound represents a sensitive method for assessing the blood flow directed to the hoof. The aims of this study were to evaluate the blood flow parameters of the lateral palmar digital artery (LPDA) in pregnant mares and to assess intra- and interrater agreement between two observers with different levels of experience. The LPDAs of pregnant Italian Standardbred mares were examined. The vessels were located with B-mode ultrasound and analyzed with col...
Bell T, Kyriazopoulou P, Mowbray C, Murphy BA.Equine headshaking syndrome is a poorly understood neuropathic pain condition presenting as uncontrollable shaking, flicking, or striking of the head. Therapeutic options are limited, and treatments are only partially successful. Currently, epidemiological information on headshaking in the Southern Hemisphere is lacking. An online survey was circulated to Australian owners of headshaking horses to collect information on triggers, symptoms, seasonality, treatments, and perceived treatment efficacy. The responses (n = 216) showed the mean age at symptom onset as 9.6 (±4.7) years. More geldings ...
Fedorka CE, Schnobrich MR, Muderspach ND, Scoggin KE, Dedman MT, Weigle KE, May MG, Twist H, Linse CR, Douglas RH, Troedsson MHT.Equine embryonic loss following the development of endometrial cups delays return to cyclicity due to the production of equine chorionic gonadotropin (eCG). Natural degradation of endometrial cups coincides with an influx of immune cells at 100-120 days of gestation, but therapeutic stimulation of reduced eCG production has been relatively unsuccessful. Recently, we observed an increase in pro-inflammatory cytokine production following the use of the immunostimulant mycobacterium cell wall fraction (MCWF). Objective: To evaluate the efficacy of hysteroscopic-guided injection of MCWF on the a...
Sill S, Zhao L, Houpt K.Salt (NaCl) is an essential nutrient for horses because their diet is low in sodium and they lose salt in sweat. Given the many types of salt block available, 342 horse owners were surveyed to see what type they offered their horses. The owners most often offered plain(30%) mineralized (29%) or Himalayan salt blocks. Next, adult mares were given two choice preference tests between plain (white) and mineralized (red) salt blocks, between mineralized and selenium (green) blocks, between plain and selenium, between Himalayan (pink) and plain and between Himalayan and selenium salt blocks. The hor...
Charlotte C P, Benoit B, Olivier M L.To evaluate secondary intention wound healing in the horse's limbs when treated with the synthetic epidermis spray (Novacika®, Cohesive S.A.S, France) or with a standard bandaging technique. Methods: Six Standardbred mares were included in the study. Four 2.5 x 2.5 cm full-thickness skin wounds were created on each thoracic limb. Two wounds were located on the dorsoproximal aspect of the cannon bone and the other two at the dorsoproximal aspect of the fetlock. Six hours after creation, wounds were randomly treated with synthetic epidermis spray or standard bandaging. The wounds were assessed ...
Woodward EM, Christoffersen M, Campos J, Betancourt A, Horohov D, Scoggin KE, Squires EL, Troedsson MH.Transient endometritis after breeding is necessary for clearance of bacteria and spermatozoa; however, in a subpopulation of mares, the inflammation fails to resolve in a timely fashion. The objective of this study was to describe the uterine inflammatory response in mares susceptible or resistant to persistent breeding-induced endometritis (PBIE) during the first 24 h after induction of uterine inflammation.Twelve mares were classified as susceptible (nZ6) or resistant (nZ6) to PBIE. Mares were inseminated over five estrous cycles and endometrial biopsies were collected at one time point per ...
Bell SA, Balasuriya UB, Gardner IA, Barry PA, Wilson WD, Ferraro GL, MacLachlan NJ.The objectives of this study were to estimate the prevalence of equine herpesviruses (EHV) 1-5 in the nasal secretions (NS) of a cohort of 12 mares and their foals from birth to 6 months of age, estimate the prevalence of EHV-1-5 infection of peripheral blood mononuclear cells (PBMC) of selected foals, and investigate phylogenetic relationships amongst the various strains of EHV-2 and 5. Virus-specific PCR assays were used to detect EHV-1-5 in NS and PBMC. A homologous portion of the glycoprotein B (gB) gene of the various strains of EHV-2 and 5 was sequenced and compared. EHV-2, 4, and 5 were...
da Silveira JC, Winger QA, Bouma GJ, Carnevale EM.Age-related decline in fertility is a consequence of low oocyte number and/or low oocyte competence resulting in pregnancy failure. Transforming growth factor (TGF)-β signalling is a well-studied pathway involved in follicular development and ovulation. Recently, small non-coding RNAs, namely microRNAs (miRNAs), have been demonstrated to regulate several members of this pathway; miRNAs are secreted inside small cell-secreted vesicles called exosomes. The overall goal of the present study was to determine whether altered exosome miRNA content in follicular fluid from old mares is associated wi...
Weiss M, Steck F, Kaderli R, Horzinek MC.After inoculation into 2 foals, Berne virus induced neutralizing antibody, but did not cause clinical symptoms. In a horizontal study of seropositive mares and their offspring, a decline of maternal antibodies and a sudden synchronous seroconversion in all foals were observed, again without clinical symptoms. The virus is widespread in the Swiss horse population and has been so during the last decade; rises in antibody titers were noted in 9% of paired sera sampled at random. Positive reactions were also obtained in serum neutralization tests and ELISA using small numbers of horse sera from Ge...
Choi YH, Varner DD, Love CC, Hartman DL, Hinrichs K.Work with lyophilized sperm helps delineate the factors required for successful fertilization. We investigated the use of lyophilized sperm in equine embryo production. In Experiment 1, sperm DNA fragmentation index was not affected by three freeze/thaw or lyophilization cycles. In Experiment 2, oocytes injected with lyophilized sperm or with sperm from a treatment in which lyophilized sperm were suspended in sperm cytoplasmic extract (SE) yielded blastocyst development rates of 0 and 28% respectively (P < 0.05). In Experiment 3, blastocyst development rate was 6-11% after injection of sper...
Feh C.A study of a herd of Camargue horses Equus caballus, showed that while the majority of high-ranking stallions held single-male harems, some sons of low-ranking mares, being low ranking themselves, formed alliances that could last a lifetime. The two stallions were each other's closest associate and preferential grooming partner. Alliances were based on coalitions in which either both partners confronted an intruder synchronously or the dominant of the pair tended the female(s) while the subordinate simultaneously displayed towards the rival. Alliance partners were of similar age but were not m...
Nunokawa Y, Fujinaga T, Taira T, Okumura M, Yamashita K, Tsunoda N, Hagio M.Serum amyloid A protein (SAA) was isolated from equine acute-phase serum by repeating Sephadex G-75 gel filtration 3 times. Quantitative measurement of equine SAA was performed by the single radial immunodiffusion technique with rabbit anti-equine SAA serum. In clinically normal horses, the SAA concentration remained relatively high from immediately after birth up to 1 week of age. After this the concentration showed periodic fluctiation in the range of approximately 13 to 30 micrograms/ml. The mean (+/- SD) concentration of SAA in foals ( or = 18 months old) was 19.37 +/- 9.41 and 21.53 +/- 9...
Troedsson MH, Loset K, Alghamdi AM, Dahms B, Crabo BG.Insemination of mares with bacteria-free equine spermatozoa results in an influx of polymorphonuclear neutrophils (PMNs) into the uterine lumen. In vitro studies have demonstrated that equine spermatozoa activate complement, resulting in cleavage of factors C5a and C3b. Since uterine secretion is rich in complement, it is likely that an interaction between spermatozoa and uterine secretion results in C5a-mediated chemotaxis and migration of PMNs into the uterine lumen. Once in the uterine lumen, the PMNs phagocytize bacteria and spermatozoa, which is an important part of sperm elimination from...
Morris LH, Allen WR.The findings of a retrospective survey of 1393 Thoroughbred mares visiting 22 studfarms in the Newmarket region of the UK during the 1998 mating season were compared with those of a similar study undertaken in 1983. The effects of mare age and status, stallion, month of mating, application of uterine treatments and other parameters on the rates of singleton and twin conception and subsequent pregnancy losses were analysed. Mare age and status significantly affected the per cycle pregnancy rate and the incidence of pregnancy loss. Overall, the mean number of matings per oestrus was 1.12 and the...
da Silveira JC, Carnevale EM, Winger QA, Bouma GJ.Ovarian follicle growth and maturation requires extensive communication between follicular somatic cells and oocytes. Recently, intercellular cell communication was described involving cell-secreted vesicles called exosomes (50-150 nm), which contain miRNAs and protein, and have been identified in ovarian follicular fluid. The goal of this study was to identify a possible role of exosomes in follicle maturation. Methods: Follicle contents were collected from mares at mid-estrous (~35 mm, before induction of follicular maturation) and pre-ovulatory follicles (30-34 h after induction of folli...
Sailer BL, Jost LK, Evenson DP.Sperm from four mammalian species were analyzed by the sperm chromatin structure assay (SCSA) and the terminal deoxynucleotidyl transferase assay (TdTA) using flow cytometry. The SCSA quantitates the susceptibility of sperm nuclear DNA to in situ acid denaturation, while the TdTA quantitates the presence of endogenous DNA strand breaks in sperm nuclear chromatin. Correlations were seen between the percentage of sperm cells showing susceptibility to in situ acid denaturation and the percentage of cells showing the presence of DNA strand breaks for humans (r = 0.56, P = 0.004), rams (r = 0.84, P...
Carnevale EM.Reproductive aging and assisted reproduction are becoming progressively more relevant in human medicine. Research with human subjects is limited in many aspects, and consequently animal models may have considerable utility. Such models have provided insight into follicular function, oocyte maturation, and reproductive aging. However, models are often selected based on factors other than physiological or functional similarities. Although the mare has received limited attention as a model for reproduction in women, comparisons between these species indicate that the mare has many attributes of a...
Decourt C, Tillet Y, Caraty A, Franceschini I, Briant C.To determine if kisspeptin could be implicated in the control of reproduction in equine species, we studied the distribution of kisspeptin neurons and their anatomical interactions with GnRH neurons in the hypothalamus of pony mares. Brains were collected in three pony mares between 2 and 4h after ovulation. One major population of kisspeptin immunoreactive cell bodies was found in the arcuate nucleus (ARC), where they extended from the middle of the nucleus to the premammillary recess. Kisspeptin immunoreactive varicose fibers extended from the preoptic area to the mammillary nuclei, with imp...
Rebordão MR, Carneiro C, Alexandre-Pires G, Brito P, Pereira C, Nunes T, Galvão A, Leitão A, Vilela C, Ferreira-Dias G.Besides the classical functions, neutrophils (PMNs) are able to release DNA in response to infectious stimuli, forming neutrophil extracellular traps (NETs) and killing pathogens. The pathogenesis of endometritis in the mare is not completely understood. The aim was to evaluate the in vitro capacity of equine PMNs to secrete NETs by chemical activation, or stimulated with Streptococcus equi subspecies zooepidemicus (Szoo), Escherichia coli (Ecoli) or Staphylococcus capitis (Scap) strains obtained from mares with endometritis. Ex vivo endometrial mucus from mares with bacterial endometritis wer...
Renzi S, Riccò S, Dotti S, Sesso L, Grolli S, Cornali M, Carlin S, Patruno M, Cinotti S, Ferrari M.The use of Mesenchymal Stromal Cells (MSCs) in orthopedic practice has recently and rapidly acquired an important role. Therapies based on the use of MSCs for the treatment of acute injuries as well as chronic inflammatory disorders are gradually becoming clinical routine. These cells have demonstrated intriguing therapeutic potentialities (i.e.: inflammation control, tissue regeneration and pathological scar prevention), that have been taken into consideration for use in both human and veterinary medicine. In particular, horses represent high performance athletes considered models for human p...
Pusterla N, Kass PH, Mapes S, Johnson C, Barnett DC, Vaala W, Gutierrez C, McDaniel R, Whitehead B, Manning J.The prevalence and epidemiology of important viral (equine influenza virus [EIV], equine herpesvirus type 1 [EHV-1] and EHV-4) and bacterial (Streptococcus equi subspecies equi) respiratory pathogens shed by horses presented to equine veterinarians with upper respiratory tract signs and/or acute febrile neurological disease were studied. Veterinarians from throughout the USA were enrolled in a surveillance programme and were asked to collect blood and nasal secretions from equine cases with acute infectious upper respiratory tract disease and/or acute onset of neurological disease. A questionn...
Christoffersen M, Woodward E, Bojesen AM, Jacobsen S, Petersen MR, Troedsson MH, Lehn-Jensen H.The objective of the study was to evaluate the gene expression of inflammatory cytokines (interleukin [IL]-1β, IL-6, IL-8, IL-10, tumor necrosis factor [TNF]-α, IL-1 receptor antagonist [ra] and serum amyloid A (SAA) in endometrial tissue and circulating leukocytes in response to uterine inoculation of 105 colony forming units (CFU) Escherichia coli in mares. Before inoculation, mares were classified as resistant or susceptible to persistent endometritis based on their uterine inflammatory response to infusion of 109 killed spermatozoa and histological assessment of the endometrial quality. ...
Allsopp MT, Lewis BD, Penzhorn BL.The intra-erythrocytic parasite Theileria equi is one of two tick-transmitted causative agents of equine piroplasmosis. Piroplasms of T. equi can be transmitted across the equine placenta and once a horse is infected, it appears to remain a lifelong carrier, since anti-theilerial drugs suppress but do not eliminate the parasite. Carrier mares may transmit the organism to their offspring and this may result in abortion or neonatal piroplasmosis, but observations by some researchers suggest that foals may be born as carriers yet remain apparently healthy. Using a T. equi-specific oligonucleotide...
Merkl M, Ulbrich SE, Otzdorff C, Herbach N, Wanke R, Wolf E, Handler J, Bauersachs S.Establishment and maintenance of pregnancy in equids is only partially understood. To provide new insights into early events of this process, we performed a systematic analysis of transcriptome changes in the endometrium at Days 8 and 12 of pregnancy. Endometrial biopsy samples from pregnant and nonpregnant stages were taken from the same mares. Composition of the collected biopsy samples was analyzed using quantitative stereological techniques to determine proportions of surface and glandular epithelium and blood vessels. Microarray analysis did not reveal detectable changes in gene expressio...
Allen WR, Stewart F.A tough, elastic glycoprotein capsule envelops the equine blastocyst between Days 6 and 23 after ovulation. It maintains the spherical configuration of, and provides physical support for, the embryo as it traverses the entire uterine lumen during Days 6-17, propelled by myometrial contractions that are stimulated by pulsatile release of prostaglandin F2alpha and prostaglandin E2. The capsule also accumulates constituents of the exocrine secretions of the endometrial glands ('uterine milk') as nutrients for the mobile embryo as it releases its antiluteolytic maternal recognition-of-pregnancy si...
Jensen RB, Danielsen SH, Tauson AH.Obesity is related to the development of several diseases like insulin resistance and laminitis in horses. The prevalence of obesity among mature Icelandic horses in Denmark has not been investigated previously. This study aimed to find the prevalence of obesity, to compare body condition score (BCS) based on owner perception with that of an experienced person and to correlate the BCS to body weight (BW) and morphometric measures in a group of mature Icelandic horses in Denmark. A total of 254 Icelandic horses (≥4 years; 140 geldings, 105 mares, 9 stallions) from 46 different farms were inc...
Klohonatz KM, Cameron AD, Hergenreder JR, da Silveira JC, Belk AD, Veeramachaneni DN, Bouma GJ, Bruemmer JE.During early pregnancy, the conceptus and mare communicate to establish pregnancy. Cell-secreted vesicles (e.g., exosomes) have been reported in serum. Exosomes contain bioactive materials, such as miRNA, that can mediate cell responses. We hypothesized that a) exosomes are present in mare circulation and quantity varies with pregnancy status, b) exosomes contain miRNAs unique to pregnancy status, and c) miRNAs target pathways in endometrium based upon pregnancy status of the mare. First, serum samples were obtained from mares in a crossover design, with each mare providing samples from a preg...
Cywes-Bentley C, Rocha JN, Bordin AI, Vinacur M, Rehman S, Zaidi TS, Meyer M, Anthony S, Lambert M, Vlock DR, Giguère S, Cohen ND, Pier GB.Immune correlates of protection against intracellular bacterial pathogens are largely thought to be cell-mediated, although a reasonable amount of data supports a role for antibody-mediated protection. To define a role for antibody-mediated immunity against an intracellular pathogen, Rhodococcus equi, that causes granulomatous pneumonia in horse foals, we devised and tested an experimental system relying solely on antibody-mediated protection against this host-specific etiologic agent. Immunity was induced by vaccinating pregnant mares 6 and 3 weeks prior to predicted parturition with a conjug...
Burns EN, Bordbari MH, Mienaltowski MJ, Affolter VK, Barro MV, Gianino F, Gianino G, Giulotto E, Kalbfleisch TS, Katzman SA, Lassaline M, Leeb T....The Functional Annotation of Animal Genomes (FAANG) project aims to identify genomic regulatory elements in both sexes across multiple stages of development in domesticated animals. This study represents the first stage of the FAANG project for the horse, Equus caballus. A biobank of 80 tissue samples, two cell lines and six body fluids was created from two adult Thoroughbred mares. Ante-mortem assessments included full physical examinations, lameness, ophthalmologic and neurologic evaluations. Complete blood counts and serum biochemistries were also performed. At necropsy, in addition to tiss...
Reghini MF, Ramires Neto C, Segabinazzi LG, Castro Chaves MM, Dell'Aqua Cde P, Bussiere MC, Dell'Aqua JA, Papa FO, Alvarenga MA.Degenerative changes of the endometrium are directly related to age and fertility in mares. Chronic degenerative endometritis (CDE) is correlated with uterine fluid retention and reduced ability to clear uterine inflammation. Recent research in the areas of equine surgery and sports medicine has shown that platelet-rich plasma (PRP) treatment acts as an immunomodulator of the inflammatory response. Therefore, the aim of this study was to determine if the uterine infusion of PRP could modulate the local inflammatory response and modify the intrauterine NO concentrations after artificial insemin...
Mazerbourg S, Overgaard MT, Oxvig C, Christiansen M, Conover CA, Laurendeau I, Vidaud M, Tosser-Klopp G, Zapf J, Monget P.IGF binding protein-4 (IGFBP-4) proteolytic degradation is a common feature of preovulatory follicles from human, ovine, bovine, porcine, and equine ovary. In all these species, the protease is a zinc-dependent metalloprotease and its ability to degrade IGFBP-4 is IGF dependent. The human intrafollicular IGFBP-4-degrading protease has recently been identified as pregnancy-associated plasma protein-A (PAPP-A). The aim of this study was to investigate whether PAPP-A is also involved in IGFBP-4 degradation in ovine, bovine, porcine, and equine preovulatory follicles and to study the expression of...
Garvey M, Suárez NM, Kerr K, Hector R, Moloney-Quinn L, Arkins S, Davison AJ, Cullinane A.Equid herpesvirus 8 (EHV-8), formerly known as asinine herpesvirus 3, is an alphaherpesvirus that is closely related to equid herpesviruses 1 and 9 (EHV-1 and EHV-9). The pathogenesis of EHV-8 is relatively little studied and to date has only been associated with respiratory disease in donkeys in Australia and horses in China. A single EHV-8 genome sequence has been generated for strain Wh in China, but is apparently incomplete and contains frameshifts in two genes. In this study, the complete genome sequences of four EHV-8 strains isolated in Ireland between 2003 and 2015 were determined by I...
Alghamdi AS, Foster DN, Troedsson MH.Seminal plasma (SP) is known to have immunosuppressive properties in several species. Equine SP has been reported to reduce or inhibit chemotaxis, phagocytosis and complement activity in vitro. The type and amount of the SP component that suppresses sperm-polymorphonuclear neutrophil (PMN) binding in vitro was determined, and the effect of such suppression on the fertility of mares inseminated in the presence of uterine inflammation, was analyzed. Sperm cells were suspended in either SP, semen extender or a mixture of both, and each was mixed with PMN-rich uterine secretions collected at 12 h ...
Smith KC, Blunden AS, Whitwell KE, Dunn KA, Wales AD.A detailed review of laboratory records for equine abortion is fundamental in establishing current disease trends and suggesting problems important for further research. Objective: To review the causes of abortion and neonatal death in equine diagnostic submissions to the Animal Health Trust over a 10 year period. Methods: The diagnoses in 1252 equine fetuses and neonatal foals were reviewed and analysed into categories. Results: Problems associated with the umbilical cord, comprising umbilical cord torsion and the long cord/cervical pole ischaemia disorder, were the most common diagnoses (38....
