Exercise in horses encompasses the physical activities that horses engage in, either through natural behaviors or structured training programs. These activities impact a horse's musculoskeletal, cardiovascular, and respiratory systems, influencing overall health and performance. Exercise can vary in intensity, duration, and frequency, and its effects are studied to understand conditioning, endurance, and recovery processes in equines. Research in this field often focuses on the physiological adaptations to different types of exercise, the prevention of exercise-related injuries, and the optimization of training regimens for various equestrian disciplines. This page compiles peer-reviewed research studies and scholarly articles that explore the physiological, biomechanical, and health-related aspects of exercise in horses.
Aarts RM, Smit IH, Ferraz GC, Rhodin M, Serra Braganca FM, Hernlund E.Assessment of equine metabolic and locomotory responses to quantified levels of physical exercise is needed to support the creation of tailored protocols for optimal training adaptation. The locomotory response to exercise in horses is not fully understood. Objective: To investigate the effect of a standardised exercise test (SET) on upper-body and limb kinematics and stride-to-stride variability in Standardbred Warmblood trotters. Methods: Experimental repeated-measures field study. Methods: Thirteen Standardbred trotters, equipped with nine inertial measurement units (IMUs), performed an inc...
Mainguy-Seers S, Grondin SM, Lavoie JP.Airway dysfunction in severe equine asthma (SEA) often results in early retirement or euthanasia of affected horses. Exercise-induced bronchodilation occurs in horses with SEA after intense treadmill exercise, but the effects of a lighter, field-applicable, training regimen remain largely unexplored. Objective: To evaluate the impact of submaximal aerobic exercise on airway obstruction during exacerbation of SEA. Methods: The preliminary phase explored the effects of a 25-min standardised exercise on the lung function of eight SEA horses. As notable bronchodilation occurred, the results were c...
Rump-Dierig I, Giers J, Frenzel C, Stöckle S, Gehlen H.This study examines seasonal changes in muscle and heart parameters in eventing horses over the course of a competition season. Blood levels of the enzymes creatine kinase (CK) and aspartate aminotransferase (AST) as well as the heart muscle-specific concentration of cardiac troponin I (cTnI) were measured before (pre), 30 min (p30) and 24 h (p24) after competitions. Creatine kinase (CK: median pre-competition = 175 U/L, 30 min post = 221 U/L, 24 h post = 140 U/L), aspartate aminotransferase (AST: pre = 319 U/L, p30 = 335 U/L, p24 = 333 U/L), and cardiac troponin I concentration (cTnI: pre = 0...
St George L, Nankervis K, Walker V, Maddock C, Robinson A, Sinclair J, Hobbs SJ.Despite growing evidence on the adaptive movement patterns that horses adopt during water treadmill (WT) exercise, underlying adaptations in muscle activity remain uninvestigated. This feasibility study aimed to develop a method for the synchronous measurement of muscle activity and movement of horses during WT exercise. Combined surface electromyography (sEMG) (2000 Hz) from selected hindlimb (biceps femoris, gluteus medius, tensor fasciae latae) and epaxial (longissimus dorsi) muscles, and three-dimensional kinematic (200 Hz) data from the back and pelvis of one (n = 1) horse were collected ...
Hammack SM, Moshage SG, Kersh ME, McCoy AM.To quantify circulating levels of myokines with a known role in bone remodeling (receptor activator of nuclear factor κ B ligand [RANK-L], matrix metalloproteinase 2 [MMP-2], and irisin) in foals in response to exercise and over the first year of life. Unassigned: 12 foals were enrolled in the study; 6 underwent an 8-week exercise program, and 6 were nonexercised controls. Blood samples were collected between 2 and 11 months of age. Receptor activator of nuclear factor κ B ligand, MMP-2, and irisin were quantified using equine-specific ELISAs. Unassigned: RANK-L, MMP-2, and irisin did not ch...
Sande A, Santosuosso E, Scharf JE, Shoemaker SJ, Temple S, Hemmerling K, Kell T, Leguillette R, Bayly WM.To compare maximal lactate steady-state (MLSS) speeds determined using a treadmill-dependent invasive reference method (RM) with 2 noninvasive methods based on heart rate variability-focused analysis of exercise ECGs. Unassigned: This was a randomized, blinded study using 7 fit Thoroughbreds. A standardized incremental exercise treadmill test (SET) where blood lactate concentration ([La]) was measured after every step facilitated calculation of speeds at which [La] was 1.5, 2.0, and 2.5 mmol/L. The RM required steady-state exercise (SS) at each of these speeds for 25 minutes or until [La] incr...
Wonghanchao T, Sanigavatee K, Pongnarudech P, Suchairat T, Jitsopin S, Wanichayanon B, Rattanakarn D, Jantakanangkoon P, Jaraswutiwong T, Kalanuson N....Horses competing in eventing competitions encounter significant challenges that increase their risk of severe injuries and metabolic disorders. Numerous studies have focused on the risk of such injuries and disorders during the cross-country segment. While one study has examined autonomic responses during this segment, research on these responses across all three phases of competition, particularly during one-day events, is still limited. The objective of this study was to analyse the autonomic responses of horses by measuring heart rate (HR) and heart rate variability (HRV) during three exerc...
Garland A, van Doorn DA, van den Boom R, Roelfsema E, Jung L, Boast M, Papadakis K, Margiotta M, Wafelbakker S, Briggs M, McCrae P, Pearson W.Up to 70% of horses in domestic equine populations are overweight. Promotion of weight loss is an important component of limiting the detrimental co-morbidities associated with excess adipose tissue. The use of a body condition score (BCS) can help equine caregivers track their horse's weight-status. However, this single score doesn't reflect changes in individual adipose depots. The purpose of this study was to characterize morphometric changes (including 8 anatomic BCS measurements that make up the whole-BCS) in horses during 3 different weight-loss programs over 10 weeks. Methods: Thirty-tw...
Jeong S, Bond S, Bayly W, Sole-Guitart A.To quantify the impact of experimentally induced dorsal nasopharyngeal collapse (NPC) on respiratory performance parameters and assess the efficacy of laser fenestration of the dorsal pharyngeal recess as a treatment option for experimentally induced NPC. Methods: Experimental interventional study. Methods: Six adult Standardbreds (one with naturally occurring disease). Methods: After an 8 week conditioning program, baseline parameters (V̇Omax, pharyngeal pressure, peak airflows, upper airway resistance) and dynamic endoscopy videos were collected in a high-speed treadmill test (T1). Dorsal N...
Saitua A, Pérez-Umbría J, García-Álamo K, Muñoz A.Dynamic mobilization exercises (DME) are an effective strategy to prevent musculoskeletal injuries and promote back health in sport horses. Previous studies focused mainly on multifidus muscle cross-sectional area, with limited data on locomotion and adaptation timing. This study evaluated locomotor changes using accelerometry, over 8 weeks of DME application in 14 sedentary horses: a DME group ( = 8) performing 10 different DME (3 neck flexions, 1 neck extension and 3 lateral bending exercises to each side), 5 repetitions of each DME per session, 3 sessions/week, and a control group ( = 6), t...
Söderroos D, Stefánsdóttir GJ, Ragnarsson S, Gunnarsson V, Jansson A.Weight-carrying capacity is important in riding horses both for performance and welfare, yet there is no standardized method to estimate individual horses' weight-carrying capacity. This study investigated the correlation between the physiological response during a (i) standardized incremental exercise test (SET) on a treadmill and a (ii) ridden incremental weight-carrying exercise test (WET). Sixteen horses (15 ± 3 years) performed both tests, including four steps with increased speed or weight load, respectively. Body weight ratio (BWR) in the WET was 20%, 25%, 30%, and 35% in each st...
Pan M, Malekipour F, Pivonka P, Morrice-West AV, Flegg JA, Whitton RC, Hitchens PL.Fractures of the distal limb in Thoroughbred racehorses primarily occur because of accumulation of bone microdamage from high-intensity training. Mathematical models of subchondral bone adaptation of the third metacarpal lateral condyles are capable of approximating existing data for Thoroughbred racehorses in training or at rest. To improve upon previous models, we added a dynamic resorption rate and microdamage accumulation and repair processes. Our ordinary differential equation model simulates the coupled processes of bone adaptation and microdamage accumulation, and is calibrated to data ...
Frontiers in geneticsOctober 1, 2025
Volume 16 1676558 doi: 10.3389/fgene.2025.1676558
Ma S, Ren W, Li Z, Li L, Wang R, Su Y, Huang Q, Dehaxi S, Wang J.Equine athletic performance is modulated by both genetic and epigenetic mechanisms. As dynamic regulators of gene expression, MicroRNAs (miRNAs) play a central role in the physiological response to exercise-induced stress18. This study focused on the top three elite Yili horses from a 5000-m race, collecting peripheral blood samples pre-race (group B) and post-race (group A). A longitudinal comparative analysis integrating miRNA omics profiling and target gene functional enrichment was performed. Nineteen miRNAs exhibited significant differential expression (10 upregulated, 9 downregulated), w...
Ergin HK, Bekdik İK, van den Hoven R, Onmaz AC.Dimethylglycine (DMG) may help delay muscle fatigue and prevent exercise-induced muscle damage in athletic animals. This study investigated the effects of intravenous and oral DMG on physiological, hematological, biochemical, blood gas, and oxidative stress parameters in exercising horses. In this study, 30 Turkish Arab saddle horses were randomly divided into three groups. Group A horses were injected intravenously with 15 mL (1500 mg) of a 10 % DMG twice daily for three days. Group B horses received 1500 mg DMG powder orally twice daily for three days, and group C (control) horses we...
Hartl B, Strohmayer C, Vali Y, Lyrakis M, Kneissl SM.Horses with hyoid bone disease may present with clinical symptoms such as exercise intolerance, resistance to ridden work, anorexia, or headshaking. This study aims to describe the computed tomographic (CT) signs and prevalence of hyoid disease and to evaluate their association with other CT changes of the head. Unassigned: In this study, four investigators conducted a retrospective analysis of their findings after reviewing the medical records of 200 horses that had undergone CT scans between 2009 and 2019. A total of 32 parameters were analyzed, and associations were evaluated between those ...
Avison A, Goderre BG, Pyle WG, Physick-Sheard PW.Sudden cardiac death is common in racehorses. Factors associated with the QT interval that could predispose to fatal cardiac arrhythmias are unknown. Cardiac restitution, expressed as a ratio of QT/TQ, has been used in humans to assess arrhythmia risk but has not been described in horses during maximal intensity exercise. Objective: Describe factors associated with the QT interval and cardiac restitution ratio (CRR) in clinically normal Standardbred racehorses under race-day conditions. Methods: Archival electrocardiograms from 42 Standardbred horses during live racing in Ontario. Methods: Obs...
Aragona F, Rizzo M, Arfuso F, Arrigo F, Fazio F, Giudice E, Faggio C, Piccione G, Giannetto C.Homeostasis and inflammation are two opposing physiological processes that are driven by the circadian clock. Objective: The study aim was to investigate the biological rhythm of the C-reactive protein (CRP) and Interleukin-6 (IL-6) in horses. Methods: Eight clinically healthy Italian saddle gelding horses, housed in individual boxes and subjected to a natural 12/12 L/D cycle, were enrolled. Blood samples were performed every 4 hours over a 48-hour period. Results: A positive correlation was found between CRP and IL-6 on both days of monitoring. Both parameters showed a daily rhythm; CRP acrop...
Aarts RM, Siegers EW, Serra Braganca FM, van Weeren PR.The need for comprehensive equine welfare assessments has become particularly evident amid ongoing debates about the social licence to operate in equestrian sports. During exercise, multiple physiological systems, principally the cardiovascular, respiratory, muscular, thermoregulatory, endocrine, and locomotory systems, undergo complex adaptations. To monitor and determine equine welfare, an approach that focuses on the quantitative monitoring of both physiological and psychological parameters to determine and understand the impact of equestrian sports on horses is essential. Existing and emer...
Bozzola C, Sala G, Stancari G, Ferrucci F, Zucca E.Exercise-Induced Pulmonary Hemorrhage (EIPH) results from alveolar capillary stress failure after strenuous exercise, leading to bleeding and pulmonary inflammation. Bronchoalveolar lavage fluid (BALF) cytology is considered the gold standard for the assessment of airway inflammation; however, it is often considered more invasive compared to tracheal wash (TW). It has been demonstrated that TW is a reliable diagnostic tool that may substitute BALF to diagnose and grade the severity of EIPH in racehorses; however, no information about airway inflammation in EIPH-affected horses has been reporte...
Dos Santos Gomes V, Dos Santos Marques JV, da Silva GN, Marmett B, Dallegrave E.The inhalation of pollutants from fossil fuel combustion increases oxidative stress and may cause genotoxic damage, a risk heightened during physical exercise due to increased respiratory rates. This concern extends to equines engaged in intense activities like show jumping. Antioxidant supplementation with vitamin E and selenium may mitigate oxidative stress induced by exercise in polluted environments. This study evaluated the effects of oral supplementation on show jumping horses subjected to physical exertion in urban (n = 10) and peri-urban (n = 10) areas with varying pollution le...
Frontiers in geneticsAugust 29, 2025
Volume 16 1651628 doi: 10.3389/fgene.2025.1651628
Su Y, Ren W, Ma S, Meng J, Yao X, Zeng Y, Li Z, Li L, Wang R, Wang J.This study employed Yili horses participating in a 5000-meter race as a model to investigate exercise-induced gene expression alterations in peripheral blood using whole transcriptome sequencing. Jugular vein blood samples from the three leading horses were collected pre- and immediately post-race, yielding 2,171 differentially expressed mRNAs (2,080 upregulated, 91 downregulated), 4,375 differentially expressed LncRNAs (4,354 upregulated), and 68 differentially expressed circRNAs (64 upregulated). GO/KEGG analyses demonstrated significant enrichment of differential mRNAs in transmembrane tran...
Alves-Junior CDB, Ferreira TC, Nunes-Pinheiro DCS.This study evaluated the dynamics of blood immune-inflammatory biomarkers in response to exercise-induced changes in jumping horses. Methods: For this purpose, adult Brazilian Sport Horses (n = 9), aged 10.1 years, both sexes, underwent a specific training test consisting of warm-up, flatwork, and jumping exercises, and recovery on a 900 m sand track over 40 min. Clinical examinations and blood collections were performed at three time points: before (T0), immediately after (T1), and 1 h after (T2) the final exercise. Hematologic and biochemical parameters, such as total protein, gl...
Čebulj-Kadunc N, Frangež R, Kruljc P.The aim of the study was to determine the fluctuations of selected physiological parameters in young Lipizzan stallions ( = 10) during the initial phase of their training as indicators of adaptation to a graded exercise load and stress exposure. For this purpose, four exercise tests (ExT) with lunging were carried out over a period of one year. Physiological parameters (gait speed, heart and respiratory rate (HR and RR), rectal and body surface temperature (RT and BST), and cortisol and lactate concentration (CORT and LAC)) were measured before and after training. In all ExT, gait speeds incre...
Wang T, Meng J, Yang X, Zeng Y, Yao X, Ren W.This study aimed to investigate the effects of training on cardiac structure and function, as well as plasma metabolite profiles in horses, in order to uncover the molecular regulatory mechanisms and cardiac remodeling under long-term exercise. We hypothesize that long-term standardized training induces physiological cardiac remodeling and differential metabolomic changes in Yili horses, which correlate with improved athletic performance. The study focuses on physiological exercise-induced cardiac remodeling, characterized by increased left ventricular wall thickness and chamber size. A total ...
Pfau T, Forbes B, Sepulveda-Caviedes F, Chan Z, Weller R.Based on fundamental mechanics, movement and force associate head and pelvic movement asymmetry with asymmetry of force production. We investigate, how often racehorses undergoing strenuous training regimens show evidence of switching between "preferred" limbs, i.e. one limb producing increased force, when assessed at monthly intervals? We hypothesize that clinical asymmetry thresholds designed for "detecting lameness" are frequently exceeded and that when applying previously established Thoroughbred-specific repeatability values, horses rarely switch between showing left- and right-sided asym...
Tranquille C, Nankervis K, Tacey J, Hopkins E, Deckers I, Walker V, MacKechnie-Guire R, Newton R, Murray R.Water treadmill (WT) exercise has become a popular tool for equine training and rehabilitation. However, few studies describe the long-term effects of WT exercise in low water on muscle development (MD). This study's objectives were to compare MD changes over a 40-week period in sport horses that regularly used WT in low water within training (Group WTH, = 55) and a control group that did not (control, = 28). Subjective MD assessments were undertaken using an adaptation of a previously published method at weeks 0, 20 and 40. For Group WTH, MD significantly increased in the neck, pelvis and h...
Lendl L, Wirth C, Merle R, Barton AK.Mild-moderate equine asthma (MEA) is a very common but underdiagnosed pulmonary disease in horses, with mild cases not showing clinical respiratory signs. This study evaluates the influence of a standardized lunging exercise test (SLET) on bronchoalveolar lavage fluid (BALF) cytology in MEA horses. We hypothesized that SLET would increase the total nucleated cell count (TNCC) and/or percentages of inflammatory cells associated with EA. In a prospective, randomized, non-blinded, between-subjects study design of two independent groups, 39 horses (17 mild and 22 moderate) were included. They were...
Sohn Y, An SJ, Forbes E, Yoon J, Kim BS, Kim JG, Ryu SH.To model lactate recovery kinetics in relation to sex, age, running speed, and racing experience, and to estimate blood lactate clearance time under passive recovery conditions that reflect current management practices in Jeju horses, a less well-characterized pony-sized indigenous breed. Unassigned: From October through December 2022, BLC was measured at baseline, 10 minutes after 800-m barrier trials (time [T]-1), and 50 minutes (T2) after 800-m barrier trials in 40 race-trained Jeju horses (2 to 4 years old). Lactate clearance was modeled using nonlinear regression with an exponential decay...
Sikorska U, Maśko M, Rey B, Domino M.Water treadmill (WT) exercise is used for horses' rehabilitation and training. Given that each training needs to be individualized for each horse, the goal is to assess whether infrared thermography (IRT) can serve as a non-invasive tool for daily monitoring of individual training and rehabilitation progress in horses undergoing WT exercise. Fifteen Polish Warmblood school horses were subjected to five WT sessions: dry treadmill, fetlock-depth water, fetlock-depth water with artificial river (AR), carpal-depth water, and carpal-depth water with AR. IRT images, collected pre- and post-exercise,...
Fiedler JM, Rosanowski S, Ayre ML, Slater JD.Participation in horse-related activities frequently involves relocating horses from the home stable to an activity venue, which might require local, regional, or international travel. In these circumstances, horses are exposed to unfamiliar surroundings and experience changes to their daily routines, which could have negative welfare impacts. An online survey was conducted in 2021 to ask experienced horse sector participants about the horse management practices that they perceived worked well and provided for positive horse welfare when undertaken at venues. Qualitative analysis identified fo...
Wilson AM, Goodship AE.Mathematical modelling of tendon thermodynamics predicted that the temperature of the central core of the equine superficial digital flexor tendon would plateau at 11 degrees C above the tendon surface temperature during a sustained gallop. A mean temperature differential (between tendon core and surface) of 5.4 (S.E. +/- 1.0) degrees C was demonstrated in vivo in four horses. Peak intra-tendinous temperatures in the range 43-45 degrees C were recorded. Temperatures above 42.5 degrees C are known to result in fibroblast death in vitro [Hall (1988) Radiobiology for the Radiologist, 3rd Edn., pp...
Irvine CH, Alexander SL.In horses, a circadian rhythm in plasma cortisol concentrations has been reported in some but not all studies. When a rhythm occurred, horses were accustomed to a management routine, comprising stabling, feeding and sometimes exercise, which may entrain a circadian pattern. In this work, we monitored plasma cortisol by collecting jugular blood through indwelling cannulae from four groups: 1): 10 untrained, unperturbed mares grazing excess pasture, bled hourly for 26 hr; 2) 4 mares housed in a barn for 48 hr before sampling every 15 min for 20-24 hr; 3) 5 mares placed in an outdoor yard for sam...
Harris RC, Marlin DJ, Dunnett M, Snow DH, Hultman E.1. Muscle buffering capacity (beta m) and dipeptide content were measured in locomotory muscles of the Thoroughbred horse, Greyhound dog and Man. 2. Beta m and carnosine contents were highest in the horse. Anserine was only found in dog muscle. 3. The higher beta m in horse and dog muscle, compared with man, appears to be predominantly due to higher muscle contents of histidine containing dipeptides in these species.
Lyle CH, Uzal FA, McGorum BC, Aida H, Blissitt KJ, Case JT, Charles JT, Gardner I, Horadagoda N, Kusano K, Lam K, Pack JD, Parkin TD, Slocombe RF....To improve the understanding of exercise related sudden death in Thoroughbred racehorses. Objective: To describe the post mortem findings in cases of sudden death associated with exercise in 268 Thoroughbred racehorses. Methods: Gross and histological post mortem findings of 268 cases of sudden death were collated and reviewed. Cases originated from 6 racing jurisdictions around the world. Sudden death was defined as acute collapse and death in a closely observed and previously apparently healthy Thoroughbred racehorse, during, or within one hour after, exercise. Cause of death as determined b...
Frisbie DD, Kawcak CE, Trotter GW, Powers BE, Walton RM, McIlwraith CW.The objective of this study was to determine the effects of intra-articularly administered triamcinolone acetonide (TA) in exercised equine athletes with carpal osteochondral fragmentation. Eighteen horses were randomly assigned to each of 3 groups. An osteochondral chip fragment was created in one randomly chosen intercarpal joint of each horse. Both intercarpal joints in the placebo control group (CNT) horses were injected with intra-articular administration (IA) of polyionic fluid. Both joints in the TA control group (TA CNT) horses were treated with 12 mg of TA in the intercarpal joint wit...
Verheyen K, Price J, Lanyon L, Wood J.In order to gain insight into those training regimens that can minimise the risk of fracture in athletic populations, we conducted a large epidemiological study in racehorses. Thoroughbred racehorses provide a suitable model for studying fracture development and exercise-related risk factors in physically active populations. They represent a homogeneous population, undertaking intensive exercise programmes that are sufficiently heterogeneous to determine those factors that influence injury risk. Daily exercise information was recorded for a cohort of 1178 thoroughbreds that were monitored for ...
Witte TH, Hirst CV, Wilson AM.Stride duration, stance duration and protraction duration are key variables when describing the gaits of terrestrial animals. Together, they determine the duty factor (the fraction of the stride for which the limb maintains contact with the ground surface), from which the peak vertical force can be estimated. When an animal changes speed, these variables change at different proportions. Limited measurements of these variables and predictions of peak limb force have been undertaken for large mammals performing high-speed over-ground exercise. This study set out to make such measurements, employ...
Minetti AE.By refining a previously published model, a simple equation for the estimation of the mechanical internal work during locomotion is presented. The only input variables are the progression speed, the stride frequency and the duty factor, i.e. the fraction of the stride duration at which a foot is in contact with the ground. The inclusion of this last variable, easily measurable, allows to obtain a single equation for both walking and running. The model predictions have been compared with the mechanical internal work experimentally obtained on humans in several conditions: speeds (range 0.8-3.3 ...
Hardeman AM, Serra Bragança FM, Swagemakers JH, van Weeren PR, Roepstorff L.Objective lameness assessment is gaining more importance in a clinical setting, necessitating availability of reference values. Objective: To investigate the between -path, -trial and -day variation, between and within horses, in the locomotion symmetry of horses in regular use that are perceived sound. Methods: Observational study with replicated measurement sessions. Methods: Twelve owner-sound horses were trotted on the straight line and on the lunge. Kinematic data were collected from these horses using 3D optical motion capture. Examinations were repeated on 12 occasions over the study wh...
Waselau M, Sutter WW, Genovese RL, Bertone AL.To determine outcome of Standardbred racehorses with moderate to severe midbody suspensory ligament desmitis (MSD) treated by means of ultrasound-guided intralesional injection of a single dose of platelet-rich plasma (PRP) followed by a program of gradually increased exercise. Methods: Nonrandomized clinical trial. Methods: 9 Standardbred racehorses. Methods: Following injection of PRP, horses were allowed a controlled, gradual return to exercise. Race records for the year prior to injury and for 3 consecutive years after horses returned to racing were reviewed. For comparison purposes, race ...
Buchner HH, Savelberg HH, Schamhardt HC, Merkens HW, Barneveld A.A kinematic analysis was carried out to compare treadmill and overground locomotion in horses at the trot. Stride variables and limb and trunk movements of 10 Dutch Warmblood horses were measured using the CODA-3 gait analysis system. Overground recordings were made on a rubber ground surface and on an asphalt track. Treadmill recordings were taken after a controlled habituation programme and at the same velocities as measured overground. On asphalt, a shorthened stride duration and a decreased vertical displacement of the withers were found compared with those on rubber ground. On the treadmi...
Johnson PJ.Certain management practices tend to promote the development of obesity (metabolic syndrome) in mature horses as they enter their teenage years. These management practices include the provision of starch-rich (high glycemic index) and fat-supplemented rations to healthy horses that are relatively inactive. Some horse breeds and ponies appear to be genetically predisposed to metabolic syndrome. The accretion of intra-abdominal adiposity by equids is associated with the development of insulin insensitivity (hyperinsulinemia), glucose intolerance, dyslipidemia, hypertension, and insidious-onset l...
Capomaccio S, Vitulo N, Verini-Supplizi A, Barcaccia G, Albiero A, D'Angelo M, Campagna D, Valle G, Felicetti M, Silvestrelli M, Cappelli K.The horse is an optimal model organism for studying the genomic response to exercise-induced stress, due to its natural aptitude for athletic performance and the relative homogeneity of its genetic and environmental backgrounds. Here, we applied RNA-sequencing analysis through the use of SOLiD technology in an experimental framework centered on exercise-induced stress during endurance races in equine athletes. We monitored the transcriptional landscape by comparing gene expression levels between animals at rest and after competition. Overall, we observed a shift from coding to non-coding regio...
Eivers SS, McGivney BA, Fonseca RG, MacHugh DE, Menson K, Park SD, Rivero JL, Taylor CT, Katz LM, Hill EW.Intense selection for elite racing performance in the Thoroughbred horse (Equus caballus) has resulted in a number of adaptive physiological phenotypes relevant to exercise; however, the underlying molecular mechanisms responsible for these characteristics are not well understood. Adaptive changes in mRNA expression in equine skeletal muscle were investigated by real-time qRT-PCR for a panel of candidate exercise-response genes following a standardized incremental-step treadmill exercise test in eight untrained Thoroughbred horses. Biopsy samples were obtained from the gluteus medius before, i...
Nunamaker DM, Butterweck DM, Provost MT.The North American Thoroughbred racehorse was chosen as a model to study the pathogenesis of fatigue failure of bone. This species has a high incidence of spontaneous fatigue failure of bone (bucked shins) during its early training. In vivo strain gauge studies of the third metacarpal bone of four young racehorses running at racing speeds showed high principal compressive strains [-4,841 +/- 572 (SD) microstrain] while two older horses had lower principal compressive strains (-3,317 microstrain measured at racing speed, -3,250 microstrain extrapolated from a slower speed run). Previously repor...
Wagner PD, Gillespie JR, Landgren GL, Fedde MR, Jones BW, DeBowes RM, Pieschl RL, Erickson HH.Arterial hypoxemia has been reported in horses during heavy exercise, but its mechanism has not been determined. With the use of the multiple inert gas elimination technique, we studied five horses, each on two separate occasions, to determine the physiological basis of the hypoxemia that developed during horizontal treadmill exercise at speeds of 4, 10, 12, and 13-14 m/s. Mean, blood temperature-corrected, arterial PO2 fell from 89.4 Torr at rest to 80.7 and 72.1 Torr at 12 and 13-14 m/s, respectively, whereas corresponding PaCO2 values were 40.3, 40.3, and 39.2 Torr. Alveolar-arterial PO2 di...
Smith RK, Birch H, Patterson-Kane J, Firth EC, Williams L, Cherdchutham W, van Weeren WR, Goodship AE.In human athletes, conditioning, training and competition are commenced before skeletal maturity. Yet in equine athletics, racing of young (age 2 years) horses remains contentious. Tendon injury persists as major causes of wastage in equine athletes. Minimising injury and associated welfare issues could involve a radical approach to the timing and implementation of conditioning and training. Tendons were examined from Thoroughbreds, Dutch Warmblood foals, working horses and also a group of wild horses to evaluate effects of age, function and exercise. Gross mechanical properties did not differ...
Mach N, Ruet A, Clark A, Bars-Cortina D, Ramayo-Caldas Y, Crisci E, Pennarun S, Dhorne-Pollet S, Foury A, Moisan MP, Lansade L.We simultaneously measured the fecal microbiota and multiple environmental and host-related variables in a cohort of 185 healthy horses reared in similar conditions during a period of eight months. The pattern of rare bacteria varied from host to host and was largely different between two time points. Among a suite of variables examined, equitation factors were highly associated with the gut microbiota variability, evoking a relationship between gut microbiota and high levels of physical and mental stressors. Behavioral indicators that pointed toward a compromised welfare state (e.g. stereotyp...
Pfau T, Stubbs NC, Kaiser LJ, Brown LE, Clayton HM.To determine whether body lean angle could be predicted from circle radius and speed in horses during lunging and whether an increase in that angle would decrease the degree of movement symmetry (MS). Methods: 11 medium- to high-level dressage horses in competition training. Methods: Body lean angle, head MS, and trunk MS were quantified during trotting while horses were instrumented with a 5-sensor global positioning system-enhanced inertial sensor system and lunged on a soft surface. Speed and circle radius were varied and used to calculate predicted body lean angle. Agreement between observ...
Hillyer MH, Taylor FG, Proudman CJ, Edwards GB, Smith JE, French NP.A case control study was performed to identify risk factors for colic caused by simple colonic obstruction and distension (SCOD) in the horse. Case horses were recruited from 2 veterinary school clinics. Control horses were population based and matched by time of year. A number of risk factors were considered in the following areas: general carer and premises information; exercise information; husbandry information (housing- and pasture-related); feeding information; breeding information; behavioural information; travel information; preventive medicine information and previous medical informat...
Geburek F, Gaus M, van Schie HT, Rohn K, Stadler PM.Regenerative and anti-inflammatory effects on tendinopathies have been attributed to blood-derived biologicals. To date the evidence for the efficacy of autologous platelet-rich plasma (PRP) treatment of naturally occurring equine tendinopathies is limited. The purpose of this placebo-controlled clinical trial was to describe the effect of a single treatment of equine superficial digital flexor tendon (SDFT) disease with PRP on clinical and ultrasonographic parameters. Twenty horses with naturally occurring tendinopathies of forelimb SDFTs were randomly assigned to the PRP-treated group (n =...
Whitton RC, Trope GD, Ghasem-Zadeh A, Anderson GA, Parkin TD, Mackie EJ, Seeman E.Bone modelling and remodelling reduce the risk of fatigue fractures; the former by adapting bone to its loading circumstances, the latter by replacing fatigued bone. Remodelling transiently increases porosity because of the normal delay in onset of the formation phase of the remodelling sequence. Protracted intense loading suppresses remodelling leaving modelling as the only means of maintaining bone strength. We therefore hypothesized that race horses with fatigue fractures of the distal third metacarpal bone (MC3) will have reduced porosity associated with suppressed remodelling while contin...
Sykes BW, Bowen M, Habershon-Butcher JL, Green M, Hallowell GD.To date, risk factors for equine glandular gastric disease (EGGD) have not been described in Thoroughbred racehorses. Objective: To determine management factors associated with EGGD, identify clinical signs in affected horses, and compare these to equine squamous gastric disease (ESGD). Methods: The study was carried out on 109 Thoroughbred racehorses from 8 training yards (3 in the United Kingdom and 5 in Australia). Methods: Gastroscopic examination alongside a questionnaire regarding management, feeding, exercise, and health. Results: Management factors and clinical signs were different for...
Rhodin M, Pfau T, Roepstorff L, Egenvall A.Lungeing is an important part of lameness examinations, since the circular path enforced during lungeing is thought to accentuate low grade lameness. However, during lungeing the movement of sound horses becomes naturally asymmetric, which may mimic lameness. Also, compensatory movements in the opposite half of the body may mimic lameness. The aim of this study was to objectively study the presence of circle-dependent and compensatory movement asymmetries in horses with induced lameness. Ten horses were trotted in a straight line and lunged in both directions on a hard surface. Lameness was in...
Stanley RL, Fleck RA, Becker DL, Goodship AE, Ralphs JR, Patterson-Kane JC.Injury to the energy-storing superficial digital flexor tendon is common in equine athletes and is age-related. Tenocytes in the superficial digital flexor tendon of adult horses appear to have limited ability to respond adaptively to exercise or prevent the accumulation of strain-induced microdamage. It has been suggested that conditioning exercise should be introduced during the growth period, when tenocytes may be more responsive to increased quantities or intensities of mechanical strain. Tenocytes are linked into networks by gap junctions that allow coordination of synthetic activity and ...
Boyde A, Firth EC.To characterise and explain the increase in density evident by computerised tomography (CT) and radiography in companion studies as a response to training, in bone in the palmar and dorsal regions of the condyles of the third metacarpal bone (Mc3) of 2-year-old Thoroughbred horses. Methods: Compositional back-scattered electron (BSE) imaging in scanning electron microscopy (SEM) and confocal scanning laser microscopy (CSLM) were conducted on polymethyl methacrylate (PMMA)-embedded mediolateral slices of the right distal Mc3 from seven 2-year-old Thoroughbred horses trained on a racetrack and s...
Witkowska-Piłaszewicz O, Maśko M, Domino M, Winnicka A.In horse racing the most acceptable way to objectively evaluate adaptation to increased exertion is to measure lactate blood concentration. However, this may be stressful for the horse, therefore, a simple, noninvasive procedure to monitor race progress is desirable. Forty Thoroughbreds attended race training, with blood samples collected at rest, immediately after, and 30 min after exercise. The lactate concentration was determined 60 s after blood collection using an Accusport. Thermal imaging of the neck and trunk areas was performed following international veterinary standards from a dista...
Rhodin M, Roepstorff L, French A, Keegan KG, Pfau T, Egenvall A.Lungeing is commonly used as part of standard lameness examinations in horses. Knowledge of how lungeing influences motion symmetry in sound horses is needed. Objective: The aim of this study was to objectively evaluate the symmetry of vertical head and pelvic motion during lungeing in a large number of horses with symmetric motion during straight line evaluation. Methods: Cross-sectional prospective study. Methods: A pool of 201 riding horses, all functioning well and considered sound by their owners, were evaluated in trot on a straight line and during lungeing to the left and right. From th...
Jones JH, Longworth KE, Lindholm A, Conley KE, Karas RH, Kayar SR, Taylor CR.This study investigated mechanisms used by horses and steers to increase O2 uptake and delivery (VO2) from resting to maximal rates and identified the mechanisms that enable horses to achieve higher maximal rates of O2 consumption (VO2max) than steers. VO2 and circulatory variables were measured while Standardbred trotting horses and steers (450-kg body mass) stood quietly and ran on a treadmill at speeds up to those eliciting VO2max. As VO2 increased in both species, heart rate and circulating hemoglobin (Hb) concentration increased, thereby increasing O2 delivery by the circulation, while ca...
Keegan KG, Yonezawa Y, Pai PF, Wilson DA, Kramer J.To compare a sensor-based accelerometer-gyroscopic (A-G) system with a video-based motion analysis system (VMAS) technique for detection and quantification of lameness in horses. Methods: 8 adult horses. Methods: 2 horses were evaluated once, 2 had navicular disease and were evaluated before and after nerve blocks, and 4 had 2 levels of shoe-induced lameness, alternatively, in each of 4 limbs. Horses were instrumented with an accelerometer transducer on the head and pelvis, a gyroscopic transducer on the right forelimb and hind feet, and a receiver-transmitter. Signals from the A-G system were...
