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.
Stricklin OE, McKenzie EC, Sriboonyapirat P, Russell DS, White CN.To determine whether Miniature Horse mares are predisposed to hemoperitoneum from nonneoplastic ovarian hemorrhage and report the clinical characteristics of this disorder. Methods: 51 equines with hemoperitoneum, including 22 nonminiature mares and 9 Miniature Horse mares, identified by searching medical records of a tertiary large animal hospital for confirmed hemoperitoneum cases between 2012 and 2023. Methods: Signs of hemoperitoneum in miniature mares included lethargy, inappetence, colic, tachycardia, and moderate to severe anemia (PCV ranging from 11% to 19%). Five miniature mares did n...
Fedorka CE, Scoggin KE, Coleman SJ, Hatzel JN, Burleson MD, Troedsson MHT.Alterations during the early stages of embryo development have been associated with long-term effects on the fetus, neonate, and adult, but this has not been investigated in horses. In recent years, intracytoplasmic sperm injection (ICSI) has gained in commercial popularity in the equine population. Research suggests an association between ICSI-produced embryos and placental malformations, but there exists little understanding of the physiology involved. Therefore, we aim to produce a complete transcriptomic analysis of chorioallantois and provide potential pathways that may be impacted follow...
Carnevale L, Tagliabue T, Rabbogliatti V, Bona R, Cavallier F.Femoral head ostectomy is considered a salvage procedure in the treatment of chronic coxofemoral joint luxation in small equids. Permanent lameness of varying degrees, largely depending on the animal's weight, and potential contralateral limb deformity may occur. The purpose of this study was to report the outcome of a small equid that, despite undergoing a femoral head ostectomy for a chronic coxofemoral joint luxation, was able to return to being ridden by children and to athletic activities. Methods: An 8-year-old Shetland pony mare (180 kg) was presented for a chronic right hind limb lamen...
Talib MT, Nasir A, Kashif M, Rahman A, Rehman AU, Akbar H, Nadeem A, Howe DK, Azam MN.The aim of this study was to determine the prevalence of anti-Neospora (N.) caninum and anti-N. hughesi antibodies in horses and to appraise the associated risk factors in the two central districts (Jhang and Toba Tek Singh) of Punjab Province, Pakistan. A total of 300 horse sera were analyzed for the presence of antibodies to Neospora spp. using a competitive ELISA. The overall prevalence of antibodies against Neospora species in horses was 25 % (75/300; 95 % CI 20.1-29.9). The prevalence of antibodies to N. caninum and N. hughesi species was 12.3 % (37/300; 95 % CI 8.6-16) and 19.3 % (5...
Abdelnaby EA, ElKader NAA, Yehia SG, Salem NY, Ramadan ES, Khattab MS, Farghali HA, Emam IA.This study aimed to demonstrate the vaginal tissue alterations via vaginal biopsy and hemodynamic alterations by introducing chromoendoscopy to analyse the effect of equine vaginitis on the oxidative and hormonal profile. Mares were divided into normal mares (N = 10) and affected mares (N = 10). Animals were subjected to Doppler ultrasonographic evaluation, endoscopic examination, oxidative stress was estimated, and biopsy samples were taken for histopathology and immunohistochemistry. Uterine body (UB) thickness (mm), circumference (mm) and area (mm) elevated significantly in infected...
Bukhari SSUH, Urooj S.In winter anestrous, prolonged melatonin secretion inhibits gonadotropin-releasing hormone (GnRH). However, synthetic GnRH analogues such as buserelin can stimulate follicular development. We aimed to investigate clinical relationship between retinol, cholecalciferol, and buserelin for inducing estrous in anestrous mares (Equus caballus). We used a total of twenty-one anestrous mares, randomly divided into three groups of seven animals. Group A received retinol, cholecalciferol, and buserelin; group B received buserelin; and group C was control. Groups A, B, and C had 71.42% (n = 5; 95% CI...
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...
de la Rebière de Pouyade G, Binard M, Deleuze S, Ponthier J.Standing caesarian section (C-section) in mares is poorly documented in the literature. It is reportedly straightforward to perform for veterinarians experienced in bovine practice and is more accessible and less expensive than recumbent techniques. The study aimed to create a survey to report the outcomes of in field C-section through a flank laparotomy with the mare standing under sedation. Unassigned: A survey was developed for field veterinarians practicing standing C-sections. Data were collected regarding the veterinarian's experience and practice type, details about the mare and the rea...
Filho RRR, França DS, Alonso MA, Riccio AV, Affonso FJ, Brito MM, Francischini MCP, Nichi M, Boakari Y, Fernandes CB.During gestation, there is a higher energy demand which increases oxygen requirements. As a result, there is an elevated production of reactive oxygen species. Notably, unlike in horses, the effects of maternal age and parity on women's oxidative profiles are well-documented. Thus, this study aimed to investigate oxidative changes in mares during the last third of gestation and the postpartum period, considering age and parity. Seventeen mares were categorized by age (3-7, 8-11, ≥12 years) and parity (nulliparous, 1-3, 4-6 parities). Oxidative processes were assessed using Thiobarbituric Aci...
Hannan MA, Watanabe H, Takeyama A, Yoshida S, Wudamu D, Lkhagvasuren N, Claes A, Stout TAE, Cheong SH, Haneda S, Nambo Y.This study evaluated the viability of in vitro embryo production using ovum pick-up (OPU) and intracytoplasmic sperm injection (ICSI) as breeding techniques for pure and crossbred Hokkaido native ponies (n = 9). Oocytes were collected using transvaginal ultrasound-guided follicle aspiration. ICSI was performed on in vitro matured oocytes using frozen semen. Embryonic cultures were monitored using time-lapse cinematography. Blastocysts were cryopreserved and, after thawing, were transferred non-surgically into recipient mares. Over nine OPU sessions, the mean number of aspirated follicles was 2...
Quattrini C, Knych HK, Magdesian KG.Alprazolam is used to facilitate mare-foal bonding in aggressive or anxious postpartum mares. In humans, alprazolam crosses the blood-milk barrier, but the amount transferred into milk is minor and compatible with breastfeeding as the relative infant dose is < 10%. Similar data are not available for horses. The aim of this study was to measure alprazolam in serum and milk of mares (milk: serum ratio) administered alprazolam, and to determine alprazolam serum concentrations in nursing foals to estimate the extent of absorption. This was a prospective observational study involving 7 healthy...
Renaudin CD, Picandet V, Kass PH.Using the equation of Hartwig et al. and the table established for light breed horses, day of gestation was predicted in 108 Warmblood (WB) and 59 racehorses (Thoroughbred [TB] and Standardbred [STB]) pregnant mares. In WB, gestational ages were predicted within 2 weeks from 100 to 200 days of gestation using biparietal diameter (BPD), aortic diameter (AortD) or femur length (FL); within 2 weeks from 100 to 250 days using BPD or AortD; within 2 weeks from 100 to 300 days using BPD alone; and within 3 weeks from 100 to 350 days using eye approximated volume (EyV) alone. In the ...
Boshuizen B, De Maré L, Oosterlinck M, Van Immerseel F, Eeckhaut V, De Meeus C, Devisscher L, Vidal Moreno de Vega C, Willems M, De Oliveira JE....Aleurone, derived from the bran layer of grains like wheat and barley, has demonstrated positive effects on energy metabolism in pigs, mice, and untrained horses, influencing glucose-insulin dynamics and gut microbiome composition. Training itself enhances insulin sensitivity in horses, similar to the improvements in performance capacity observed in human athletes. This study aimed to investigate whether aleurone supplementation provides additional benefits to training by modulating insulin metabolism and gut microbiota in Standardbred mares. Unassigned: Sixteen Standardbred mares (aged 3-5 ye...
Bouquet A, Nicol C, Díez-León M.The natural behaviour of wood-chewing (WC) in horses may, under certain conditions, become excessive or it may precede crib-biting . However, the potential causes of WC, including frustrated foraging motivation) or developmental exploratory or teething behavior are poorly understood. We studied WC in 31 mares and their foals, examining associations with browsing access, stocking density, foal sex and performance of other non-nutritive oral behaviors. Behaviors (counts/hour) were recorded by all-occurrences sampling during focal, continuous observations of grazing,resting and suckling for 20 ...
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% ...
Hosseinzadeh S, Nofouzi K, Hasanzadeh F, Esmaeili S, Ayen E.Q fever is a frequently occurring illness that is induced by the bacterium ) that can infect humans and various animals. It targets the macrophage cells in the tissues, and circulating monocytes. Unassigned: This study was conducted between 2022 and 2023 in the West Azerbaijan and Ardabil provinces of northwestern Iran to examine the presence infection of . Specimens were obtained by swabbing from 140 mares (70 from each province) and 20 stallions (10 from each province) which were apparently healthy, and their DNA was analyzed using quantitative PCR assay detecting the element of the bacteri...
da Fé VCS, Dos Santos VMO, de Lima ACB, Hernandes MSP, Caldara FR, Gomes MNB.This study aimed to evaluate the effect of auditory stimuli on mares and geldings during social isolation and movement restriction, and their ability to promote the reduction of stress responses. The research was conducted with eight Pantaneiro horses, divided into Experiment I (4 mares) and Experiment II (4 geldings), both experiments were executed equally using a 4x4 Latin square design with experimental (classical, country and new age) and control (no music) treatments. Physiological parameters (heart rate, heart rate variability, respiratory rate, ocular temperature by infrared thermograph...
Ziadi C, Valera M, Laseca N, Perdomo-González D, Demyda-Peyrás S, de Los Terreros AR, Molina A. By simultaneously integrating both genotyped and non-genotyped animals into genetic evaluation, the single-step genomic BLUP method enhanced the accuracy of genetic assessments. This study aimed to compare the increase in prediction reliability (R) between restricted maximum likelihood (REML) and single-step genomic REML (ssGREML) in the Pura Raza Española (PRE) horse breed. The dataset comprised reproductive records for seven fertility traits from 47,502 females, with a total of 57,316 animals represented in the pedigree. A total of 4009 animals were genotyped using the EQUIGENE 90K SNP ar...
Parra MT, Ayala MSF.A retrospective study was conducted at the Foal Care Equine Perinatology Center in Colombia from October 2017 to May 2023. The goal was to analyze the most frequent pathologies, as well as assess the sexes, ages, and breeds of the patients, with an emphasis on the perinatal population. Out of 945 clinical histories, 776 pertained to perinatology. Survival rates were calculated, and a descriptive analysis was performed. The overall survival rate for neonates was 73.6%, with females constituting 57% of the neonatal patients. The most prevalent breed among mares and neonates was the Creole Colomb...
Viljanto M, Cutler C, Habershon-Butcher J, Hincks P, Scarth J.The use of testosterone in racehorses is predominantly monitored using international urine and plasma concentration-based thresholds and complementary steroid ratios. To date, there has been no published pharmacokinetic study on transdermally applied testosterone products in horses and whether their use could result in adverse analytical findings. Therefore, quantitative analysis of testosterone and epitestosterone in urine and testosterone in plasma samples was performed following a pilot multi-dose transdermal Testogel administration (1 mg/kg once a day for 7 days on clipped skin) to one...
Janczarek I, Gazda I, Barłowska J, Kurnik J, Łuszczyński J.It is assumed that horses have a strong herd instinct that cannot be suppressed by any form of social support from humans. The aim of this study was to assess the behaviour and heart rate parameters of horses that received various forms of human support during short-term social isolation. The research material consisted of 12 clinically healthy recreational warmblood mares and geldings. The test was carried out four times. The research test consisted of two parts, which began in the presence of accompanying horses and under conditions of social isolation, with and without support provided by a...
Li J, Matsumoto T, Liu H, Li C, Murase H, Yamamoto Y, Nagaoka K.Accurate prediction of the timing of parturition is crucial to ensure the health and well-being of both mares and foals. However, equine pregnancies are characterised by significant variability in gestation length, unique endocrine mechanisms, and subtle physiological changes before parturition. Objective: To investigate the characteristic changes in the peripheral metabolites of mares before and after parturition using metabolomic approaches. Methods: Longitudinal in vivo metabolic study. Methods: Plasma samples (n = 95) were collected from successfully foaling Thoroughbred mares (n =...
Roig-Pons M, Bachmann I, Freymond SB.Finding feeding strategies that meet horses' needs without compromising health is essential for optimising welfare, particularly in group housing, where limited hay availability increases aggression and injury risks. Recently, two strategies have emerged: portioning daily intake into smaller, frequent meals using time-controlled hay racks, or slowing intake with "slow-feeders." However, the effects of such management practices on horse behaviour remain underexplored. We conducted a cross-over study with 18 mares divided into four groups to compare three feeding strategies: "traditional" (3 of ...
Murase H, Wachi S, Matsuyama R, Makita K, Sato F.Pituitary pars intermedia dysfunction (PPID) is an age-related disease considered to have a negative impact on fertility. To understand the true impact of PPID on fertility, the influence of age must be considered. Objective: This study aimed to assess the impact of PPID on fertility while accounting for the effect of aging. Methods: A total of 332 Thoroughbred mares aged 10-20 years and managed across 137 private farms in Hidaka, Hokkaido, Japan were classified as PPID, equivocal, or non-PPID based on plasma adrenocorticotropic hormone concentration in 2019 and 2020. The prevalence of PPID an...
Roncaglia-Pereira VA, Dumard CH, Monteiro-Machado M, Melo PA, Fonseca J, Meirelles L, Cunha-Ribeiro L, Souza P, da Silva JL, Castilho L....In this study, we aim to report the persistent presence of anti-SARS-CoV-2 immunoglobulins in pre-immunized mare offspring. Three mares from Vital Brazil Institute were pre-immunized with recombinant SARS-CoV-2 spike protein and became pregnant during this period. After parturition, the mares' serum and colostrum/milk and foal serum were collected over 6 weeks. Our results have shown high and persistent presence of IgG and neutralizing antibodies over the weeks not only in the mares' serum, as expected, but in mares' colostrum/milk and foal serum as well-what were very surprising. This peculia...
Segabinazzi L, Lisboa FP, Zutter B.Limited response to conventional therapies and rising antibiotic resistance emphasize the need for alternative treatments for infectious endometritis. A recent in vitro study showed promising antimicrobial activity of a commercial uterine cleaning sanitizer (UCS) against endometritis pathogens. However, its safety and efficacy in mares remain untested. Objective: This study aimed to assess the clinical safety of intrauterine infusion of UCS in reproductively sound mares. Methods: Exp. 1. Six healthy mares with endometrial biopsies classified as I or IIA had two intrauterine infusions of UCS pe...
Barbosa LA, Maran AP, de Almeida MER, Guimarães EC, Bringel B, Douglas RH, Lima TFG, da Silva ESM.A longer endometrial exposure to estradiol before progesterone has been shown to be beneficial in cyclic and acyclic recipient mares. Therefore, the selection of an estradiol ester that promotes longer endometrial exposure to estradiol using a single administration would be advantageous when preparing acyclic mares as embryo recipients. This study investigated plasma estradiol profiles in acyclic mares after a single administration of 17-β estradiol (17-β), estradiol benzoate (EB) and estradiol cypionate (EC), and the correlation between plasma concentrations and endometrial edema. Fifteen n...
Wilson CS, Carrick J, Begg A, Shearer P, Stewart M, Brookes VJ.Despite emerging disease syndromes in Australian Thoroughbred horses in recent years, there is no formal surveillance for fetal loss in the industry. This study aimed to characterise the distribution of equine pregnancy loss > 45 days of gestation in a major Thoroughbred breeding region to provide insights into causes, prevention, and surveillance feasibility. Methods: Data were collected from 574 fetal loss submissions to veterinary pathology services between February 2015 and November 2021. Variables included date of fetal loss, gestational age, diagnosis, foal weight, and mare age. Dia...
Bailey VN, Gilbert BM, Vetter M, Oberhaus EL.The mechanism by which photoperiod influences the hypothalamic-pituitary-gonadal (HPG) axis and regulates seasonal reproduction in horses has yet to be fully elucidated. The hypophyseal pars tuberalis (PT) has been indicated as a critical site for the transduction of melatonin signals through melatonin-responsive, PT-specific cells that produce thyroid-stimulating hormone (TSH) in many mammalian species. However, this has yet to be investigated in horses. The objective of this study was to explore the interaction of melatonin and thyroid-stimulating hormone in the equine HPG axis. Pituitaries ...
Vallejo-Soto P, Dorado J, Herrera-García R, Álvarez-Delgado C, Gómez-Laguna J, Santiago Á, Manrique M, González Ariza A, León Jurado JM....Assisted reproductive techniques are often extrapolated from horses to donkeys, despite poorer fertility outcomes in jennies. This issue has been attributed to unknown uterine species-specific differences. This study compared, through histomorphometry, the endometrium of jennies and mares. Endometrial biopsies (N = 12) were taken from reproductively sound jennies (n = 6) and mares (n = 6) in estrus. Histomorphometric analysis evaluated luminal (LE, µm) and glandular epithelium height (GE, µm), glandular lumen diameter (LD, µm), glandular area (GA, µm), the number of glands (#G), and glandu...
