Experimental methods in equine research encompass a variety of techniques and procedures used to investigate physiological, behavioral, and health-related aspects of horses. These methods are designed to collect data that can enhance the understanding of equine biology and inform veterinary practices. Common experimental approaches include controlled trials, observational studies, and laboratory-based experiments. Techniques may involve the use of non-invasive imaging, biochemical assays, and physiological monitoring to assess parameters such as metabolic function, locomotion, and disease progression. This page compiles peer-reviewed research studies and scholarly articles that explore the application, development, and evaluation of experimental methods in the study of equine science.
Science (New York, N.Y.)July 19, 1946
Volume 104, Issue 2690 53-54 doi: 10.1126/science.104.2690.53
Sulkin SE, Goth A, Zarafonetis C.Anesthesia, by ether, is effective in the treatment of western equine encephalomyelitis in mice. Of mice treated with deep ether anesthesia soon after the intracerebral injection of western equine virus, only 58 per cent developed the disease as compared with 92.4 per cent of control animals. When anesthesia was delayed the approximate length of the incubation period, 60 per cent of the animals developed the disease as compared with 92.4 per cent of the controls. In addition, ether anesthesia delays the development of central nervous system symptoms not only when administered soon after the in...
Bang FB.The titration curve for the virus of Eastern equine encephalomyelitis inoculated into the 10 day old chick embryo shows that the maximum increase in virus content continues until shortly before the generalized destruction of the embryo is apparent. This is followed by a stationary phase. Histological studies of infected embryos fail to demonstrate selective tissue destruction, and titrations show the virus to be distributed throughout the egg, although concentrated in the embryo. The chorioallantoic membrane gradually becomes increasingly resistant with age to both the Eastern and Western viru...
King LS.The behavior of a fixed strain of Eastern equine encephalomyelitis virus was studied in guinea pigs after intraocular inoculation. Such inoculation concerns the central and not the peripheral nervous system. The susceptibility to intraocular injection lies midway between the highly virulent intracerebral and the quite avirulent peripheral routes. The virus must act for 10 to 13 hours in order to induce a fatal infection. Removal of the inoculated eyeball before this interval almost always prevents fatality although it may allow immunity to develop. The virus, at suitable intervals after inject...
Smith T.The foregoing and earlier data taken together demonstrate that an active immunity lasting several years can be produced in guinea-pigs, by the injection of toxin-antitoxin mixtures which have no recognizable harmful effect either immediate or remote. They also show, what might have been anticipated, that under the same conditions mixtures which produce local lesions and which, therefore, contain an excess of toxin produce a much higher degree of immunity than the neutral mixtures, and that an excess of antitoxin reduces the possibility of producing an active immunity, and may extinguish it alt...
To document morphologic changes that occur in equine intestinal serosa after experimentally induced ischemia and subsequent reperfusion (jejunum, ascending colon) or after intraluminal distention and decompression (jejunum). Methods: Morphologic effects of ischemia-reperfusion or intraluminal distention-decompression determined on the serosal layer of the equine jejunum. The large colon serosa was evaluated after ischemia-reperfusion injury. Methods: Seven adult horses. Methods: After induction of general anesthesia and ventral median celiotomy, ischemia was created by arteriovenous (AVO) and ...
In horses, osteoarthritis (OA) mostly affects metacarpophalangeal and metatarsophalangeal (fetlock) joints. The current modalities used for diagnosis of equine limb disorders lack ability to detect early OA. Here, we propose a new alternative approach to assess experimental cartilage damage in fetlock joint using Acoustic Emissions (AE). Objective: To evaluate the potential of AE technique in diagnosing OA and see how AE signals changes with increasing severity of OA. Methods: An in vitro experimental study. Methods: A total of 16 distal limbs (8 forelimbs and 8 hindlimbs) from six Finn horses...
Ramsaran LN, Byron M, Parry S, Lection J, Back B, Grenier J, Cheong SH, Diel de Amorim M.Real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR) is a technique that allows for the semi-quantification of mRNA transcripts present within a tissue of interest. Differences in the relative abundance of mRNA between samples detected by RT-qPCR require normalization with a reference gene or genes whose transcript abundance is stable within the tissue of interest independent of experimental conditions. In the field of equine reproductive studies, ACTB, GAPDH and B2M genes are the most widely used as reference genes for the normalization of RT-qPCR results. However,...
Rodrigues MF, Neves AP, Ferreira R, Pessoa GA, Araujo DN, de Souza GV.Melatonin has demonstrated beneficial effects in regulating inflammatory processes in various tissues, but its role in mare uterine physiology remains unclear. Objective: To investigate the effects of melatonin on the gene expression of cytokines (IL-1β, IL-6, IL-8, IL-10, and TNF-α) in equine uterine explants cultured for 6, 12, or 24 hours. Methods: The study was divided into two experiments. Part 1 aimed to evaluate the cytotoxicity of melatonin at concentrations of 0, 0.5, 1, 2, 4, and 8 mM on endometrial cells. Part 2 aimed to determine the expression of inflammatory cytokines in uterin...
Aliani C, Lorenzetto Bologna C, Francia P, Bocchi L.Standing equine computed tomography (CT) acquisitions are susceptible to residual postural sway, which can introduce view-inconsistent motion and degrade image quality. External optical tracking based on ChArUco fiducials is a promising, low-cost strategy to enable projection-wise motion compensation, yet quantitative guidance on how camera-marker geometry affects pose-estimation performance remains limited. This CT-motivated benchtop study characterizes how the relative camera-ChArUco configuration influences both the accuracy (bias with respect to ground truth) and the precision (repeatabili...
Shroff K, Underwood C, Stefanovski D, Hopster K, Slack J.To determine transthoracic impedance (TTI) in adult horses using an exponential biphasic defibrillator and investigate patient and technique factors influencing TTI. Unassigned: A randomized crossover design with 2 phases was used. Phase 1: TTI was measured in dorsal and lateral recumbency, with and without manual pressure on the electrodes in deceased horses immediately following euthanasia. Phase 2: TTI was measured in dorsal recumbency during inspiration and expiration using anesthetized live horses sourced from 2 terminal studies. Mixed-effects linear regression modeling was performed to a...
Becerro-Rey L, Martín-Cano FE, Silva-Rodríguez A, Ortega-Ferrusola C, da Silva-Álvarez E, Zabalo-Palomo C, Gil C, Peña FJ.Commercial extenders for equine semen typically contain high glucose concentrations; however, recent research indicates that these supraphysiological concentrations of glucose may be detrimental. Spermatozoa lack translational activity and depend on post-translational protein modifications for their regulation. Supraphysiological glucose concentrations are known to modify cell regulation, and we hypothesize that post-translational modification deregulation associated with supraphysiological glucose concentrations occurs in spermatozoa extended in high glucose media; and increasing the concentr...
Parker JL, Berghaus LJ, Gordon J, Mathews L, Akinde MA, Hall DB, Peroni JF.Mesenchymal stromal cells (MSCs) support wound healing through immunomodulation and by promoting tissue organization. Cell tracking studies demonstrate that MSCs must 'home' to injuries in order to participate in reparative processes. It has been reported that in vivo cell tracking labels, including superparamagnetic iron oxide particles (SPIOs), can alter MSC homing. Homing is thought to occur in coordinated steps including tethering, activation, arrest, diapedesis, and migration, guided by chemotactic stimuli. Equine distal limb injuries, which are commonly treated with MSCs, possess a disti...
Woods T, Dixon J, Melvaine C, Fraser B.To determine the ideal location of a medial tenoscopic portal in the equine carpal flexor tendon sheath (CFTS) using contrast computed tomography (CT). Methods: Experimental cadaver study. Methods: A total of 20 entire forelimbs from adult Standardbred horses. Methods: Contrast media diluted in saline was injected into the CFTS from a lateral approach before manually flexing and extending the limb 20 times to disperse the contrast solution. The limbs were placed in lateral recumbency and a capped 21-gauge 1.5 inch needle was placed approximately 5 mm proximal and 32 mm caudal to the palpab...
Beaumont RE, Flood C, Guest DJ.Interleukin 1 beta (IL-1β) is upregulated following a tendon injury and in vitro studies have shown that it leads to numerous negative effects on tendon cell function and gene expression. IL-1β activates nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and we hypothesised that inhibiting NF-κB activation would mediate the negative effects of IL-1β on equine tendon cells in 3-dimensional (3D) cultures. Results: Here, we tested three inhibitors of NF-κB signalling (Bortezomib, BAY11-7082 and Wedelolactone) along withTJ-M2010-5, an inhibitor of MyD88, which is a critic...
Dindo S, Tovar-Pascual L, Baldassarro VA, Bucci D, Mislei B, Spinaci M, Ortiz-Rodriguez JM.Nanoplastics (NP) accumulation in biological tissues and their adverse effects on fertility through inflammatory and oxidative stress responses have recently been described as consequences of global plastic pollution. However, little is known about the impact of NP on gametes. This study aimed to assess the internalization of NP and their effects on mature equine spermatozoa. Frozen-thawed ejaculates from five stallions were divided into untreated control (CTR) and samples supplemented with different concentrations (10, 50, 100 and 200 μg/mL) of 30 nm polystyrene NP. At baseline (T0), and a...
Larson MK, Gaffney C, Hoagland C, Jayawickrama J, Kamm JL.To determine the xenogen-free serum source that provides the greatest number of live equine mesenchymal stromal cells (MSCs) while maintaining the MSC phenotype. Unassigned: Equine bone marrow-derived MSCs from 8 horses were cultured for 7 days in media containing one of the following serum treatments: 10% xenogeneic serum, 10% or 20% commercial allogeneic equine serum, 10% autologous serum, 10% equine pooled platelet lysate (PPL), or a staged media reduction of xenogeneic media. Live cell numbers, MSC viability, and MSC immunophenotype were compared. Unassigned: The use of 10% commercial allo...
Yang S, Xiao J, Mu L, Li C, Dai S, Li S, Cui Y, Xu Y.Between the third and sixth centuries AD (Anno Domini), the Xianbei emerged as a dominant nomadic power in the Eastern Eurasian Steppe, distinguished by their exceptional equestrian culture and the pivotal role of cavalry in warfare. Despite their historical significance, detailed knowledge of their cavalry's weaponry and equipment-particularly armour-remains fragmentary. As a critical element of military technology, armour offers valuable insights into ancient combat strategies and cultural practices. However, research on early Chinese cavalry armour has been constrained by limited textual re...
Larriva-González F, Erráez-Guaicha JE, Torres-Ordóñez KE, Duma M, Larriva-Salazar S, Galarza DA.This study evaluated the cryoresistance of stallion sperm frozen by ultra-rapid (UR) methods using microspheres and straws or by the conventionally-slow (CS) method. Sixteen ejaculates from four stallions were each divided into three aliquots according to the freezing method: UR freezing in 30-μL spheres (UR-Spheres) by direct immersion in liquid nitrogen (LN); UR freezing in 0.25-mL straws (UR-Straws) by direct horizontal submersion in LN; and CS freezing in LN vapors. Ultra-rapid freezing medium included 100 mM trehalose +1 % BSA, and the CS freezing medium contained 5 % dimethylformamid...
Muñoz-García CC, Soriano-Campos MP, Luis-Calero M, Gallardo-Soler A, González-Fernández L, Macías-García B.The use of mesenchymal stromal cells (MSCs) in equine reproduction is increasing its interest in the treatment of specific pathologies. MSCs have been isolated from follicular aspirates obtained during transvaginal oocyte aspiration in women, offering a novel source for autologous therapies in reproductive treatments. However, this approach has not been tested in mares despite the common use of transvaginal oocyte aspiration for oocyte collection to produce equine embryos in vitro. Our study aimed to investigate the feasibility of isolating MSCs from equine ovarian follicular aspirates obtaine...
Delcourt V, Pinetre J, Chabot B, Barnabé A, Cacault M, Loup B, Becher F, Fenaille F, Popot MA, Garcia P, Bailly-Chouriberry L.Data-independent acquisition (DIA) methods employing a scanning quadrupole were recently described across multiple platforms. These strategies display remarkable performances in untargeted proteomics studies thanks to rapid duty cycles, leading to ultrashort liquid chromatography gradients while maintaining enough data points per peaks when coupled to fast-scanning mass analyzer. In this article, we perform the evaluation of three data acquisition strategies named diaPASEF,slicePASEF, and prmPASEF on a trapped ion mobility spectrometry quadrupole-time-of-flight (TIMS-Q-TOF) mass spectrometer f...
Khorsand F, Hamali H, Qasemi-Panahi B, Tohidkia M.This study evaluated the effects of supplementation of the freezing extender with different concentrations of silymarin on the quality of frozen-thawed Arabian stallion spermatozoa. Semen samples from three stallions (1, 2, and 3) were suspended in the freezing extender without or with silymarin (0, 25 μg/mL, 50 μg/mL, 75 μg/mL, and 100 μg/mL) and cryopreserved in 0.5 mL straws. After 1 month of storage, the frozen semen samples in straws were thawed and evaluated in terms of viability, mitochondrial membrane potential, kinematic parameters, total and progressive motility, plasma membrane ...
Lefèvre RA, Barluet de Beauchesne L, Sabarros F, Briefer Freymond S, Ramseyer A, Keller M, Reby D, Fitch WT, Briefer ÉF.Understanding why the frequencies of some species' vocalizations are far above or below those predicted by body size is key for explaining the remarkable diversity of mammalian vocal behavior. Horses, among the largest terrestrial mammals, provide a clear example of such deviation: their whinnies contain a very high fundamental frequency (>1,000 Hz) in addition to a second, lower one (∼200 Hz). While the lower fundamental frequency of whinnies is readily attributed to vocal fold (laryngeal) vibrations, the biomechanical processes underlying the production of the higher one remain unknown. Us...
Helmer A, Hacohen A, Bart O.Equine-Assisted Services (EAS) encompass a range of therapeutic interventions utilizing equine interactions to achieve therapeutic goals. This study explores heart rate synchronization between horses and riders during mounted and unmounted interactions, focusing on its potential implications for emotional regulation. A total of 25 participants aged 6-12 took part in the study, which included two groups: novice riders diagnosed with Attention Deficit Hyperactivity Disorder (ADHD) (n = 15) and experienced neurotypical riders (n = 10). Heart rate measurements were obtained using Polar Equ...
Dlugopolska D, Siwinska N, Noszczyk-Nowak A.Asthma is a multifactorial respiratory disease that naturally occurs in horses, humans, and cats, presenting common clinical signs and species-specific mechanisms. This review addresses the impact of asthma on the cardiovascular and neurological systems, with a primary focus on horses. It highlights the need for new biomarkers beyond the respiratory system due to diagnostic difficulties in animals. A comprehensive literature search was conducted using PubMed and Google Scholar, focusing on cardiovascular and neurological manifestations of asthma in humans, horses, cats, and experimental animal...
Lanning BA, Smith CM, Ugale C, Nazarenko E, Marchand WR.Equine-assisted services (EAS) are used for civilian and military trauma survivors to reduce depression and posttraumatic stress symptoms. While early scientific evidence supports the benefits of EAS, the neurophysiological mechanisms underlying these benefits are unknown. The specific aims of this exploratory study were to determine (1) whether functional near-infrared spectroscopy (fNIRS) neuroimaging can be used to explore neural responses of EAS veteran participants and (2) the correlation between neural responses and psychological outcomes of the participants interacting with equines. Fif...
Hu B, Gao S, Zhang H, Li Q, Li G, Zhang S, Xing Y, Huang Y, Han S, Tian Y, Zhang W, He H.Rhodococcus equi (R. equi) is a Gram-positive zoonotic pathogen that frequently leads to illness and death in young horses (foals). This study presents the complete genome sequence of R. equi strain BJ13, which was isolated from a thoroughbred racehorse breeding farm in Beijing, China. Results: The BJ13 genome has a length of 5.30 Mb and consists of a complete chromosome and a plasmid measuring 5.22 Mb and 0.08 Mb, respectively. We predicted 4,929 coding gene open reading frames, along with 52 tRNAs and 12 rRNAs. Through analysis of mobile genetic elements, we identified 6 gene islands and ...
Smith CM, Weimann K, Widick M, Merritt T, Christensen H, Siegel M, Pan Z, Gabriels RL.The purpose of this paper is to serve as a catalyst for the human-animal interaction research field to improve scientific rigor and accelerate the knowledge of field-based physiological responses during equine-assisted services in youth with autism spectrum disorder. This paper outlines the best practices for collecting and analyzing electrocardiogram and electrodermal activity in youth with autism spectrum disorder, utilized during a 10-week therapeutic horseback riding intervention.•Motivation strategies such as device choice, reward systems, and a visual schedule should be implemented to ...
Daniels S, Martin S, Harris P, Moore-Colyer M.The in vitro gas production system (GPS), developed to estimate degradation of ruminant feedstuffs, has been adapted for equine use. This study aimed to characterise the bacterial community profile and metabolome of donor faeces and faecal inoculum within the GPS when fermenting the same diet as faecal donors. Six Welsh ponies on identical diets were faecal donors with samples collected for microbiome profiling and system inoculation. Gas production (manual pressure transducer technique) was performed for 156 h with 2 replicate bottles from each donor harvested at 8,20,28 and 36 h. Faecal an...
Journal of biomechanicsJanuary 16, 2026
Volume 197 113169 doi: 10.1016/j.jbiomech.2026.113169
Collins AE, Wayne JS, Ferrando CA, De Vita R.This experimental study characterizes the elastic behavior of male and female equine genital tissues using uniaxial tensile testing, with strain measurements obtained via digital image correlation. Dog-bone-shaped tissue specimens were excised from mares and geldings (n=23 from female specimens and n=42 from male specimens) with all specimens aligned along the circumferential direction (CD) of the vagina, penis, and scrotum. The results include load-displacement data, stress-strain data, and tangent moduli for the penile sheath, vaginal canal, and scrotum, with strain measured in both the CD a...
Van Buren SL, Petersen JL, Brown CT, Finno CJ.With advancing genomic technologies, single-nucleotide polymorphism (SNP) arrays and whole genome sequencing (WGS) have become essential tools in equine genetic research. In this study, we assessed the concordance in SNP calls and trait-mapping efficacy by comparing data of 21 horses both genotyped on the Equine 670 K SNP array and sequenced at either ~12× or ~30× depth. Our analysis revealed that higher sequencing depths were significantly associated with fewer discordant calls between platforms. Additionally, we investigated the most frequent no-call and discordant positions and identifi...
Naber A, Kreuzer L, Zink R, Millesi E, Palme R, Hediger K, Glenk LM.This exploratory study aimed to analyse physiological interaction processes in equine-assisted-therapy (EAT) between client, therapy horse and therapist. Methods: We measured heart rate (HR), heart rate variability (HRV) and cortisol levels before, during and after a standardized therapy session and a control condition in one therapist, four therapy horses and ten female clients in emerging adulthood (Mn = 21.8 years, SD = 3.39). The clients were diagnosed with mild (N = 5) to moderate (N = 5) intellectual disability (ID). Results: There was no significant change in the client's HR, HR...
Suganuma K, Fujita G, Macalanda AMC, Regilme MAF, Izumida H, Inoue N, Acosta TJ.Horseflies are pests that cause discomfort from blood-sucking and disease transmission, and economic losses in the equine industry. This study evaluated the efficacy of horsecloth impregnated with icaridin in reducing horsefly attacks and deterring horseflies. Repellent activities were evaluated under three conditions: treatment 1 (no horsecloth), 2 (horsecloth without icaridin), and 3 (horsecloth impregnated with icaridin), using three native Hokkaido horses (Dosanko) and three mixed-breed horses (Dosanko and Haflinger) in July 2023 at a riding horse club in Hokkaido, Japan. Treatment 3 signi...
Gaitan HM, Mudge MC, Litsky AS, Arruda AG, Gardner AK.To compare strength of left paramedian colopexies using various techniques in equine ex vivo models. Methods: Experimental study. Methods: Equine cadavers euthanized for nongastrointestinal pathology (36 specimens derived from 9 horses). Methods: Colopexies were performed after euthanasia. Suture pattern (horizontal mattress vs. cruciate) and incorporation of dorsal sheath of the rectus abdominis (partial-thickness) versus incorporation of dorsal and ventral sheath of the rectus abdominis (full-thickness) were evaluated. Single cycle load to failure, work to peak load, stiffness, and mode of f...
Douglas HF, Brandly J, Hopster K.To investigate the effects of FLow-controlled EXpiration (FLEX) ventilation expiration time and speed on respiratory and pulmonary mechanics in anesthetized horses in dorsal recumbency. Methods: 6 healthy adult research horses. Methods: In this randomized crossover experimental study, horses were anesthetized 3 times and were ventilated each time for 60 minutes using conventional volume-controlled ventilation (VCV), linear emptying of the lung over 50% of the expiratory time (FLEX50), or linear emptying of the lung over 100% of the expiratory time (FLEX100) in a randomized order. The primary o...
Guyonnet AE, Whishaw IQ.The domestic horse (Equus ferus caballus) makes dung deposits to form "stud-piles" and compulsively examines dung droppings, suggesting that dung contains species-relevant information. The present study investigates horses' use of location (place), odor (object) and memory for dung sniff encounters. Horses were video recorded in 2 indoor and 4 outdoor riding arenas as they were taken at different time intervals to experimenter-determined objects or dung deposits that they could sniff. Frame-by-frame video analysis measured approaches, sniff duration, nostril use, ear position and blinking asso...
