The topic of muscle in horses encompasses the study of equine muscle structure, function, and physiology. Muscles in horses are responsible for movement, posture, and various metabolic processes. They are composed of muscle fibers that contract and relax to produce motion and generate force. Research in this area often focuses on muscle development, adaptation to exercise, and the impact of nutrition and training on muscle performance. Conditions such as muscle fatigue, injury, and disorders like equine exertional rhabdomyolysis are also explored. This page compiles peer-reviewed research studies and scholarly articles that investigate the anatomy, physiology, and clinical aspects of muscle in equine species.
Berti A, Liguri G, Stefani M, Nassi P, Ramponi G.Horse muscle acylphosphatase antibodies were obtained by immunizing rabbits with the highly purified antigen cross-linked with glutaraldehyde. Specific antibodies were purified from the immunoglobulin fraction by affinity chromatography using a matrix coupled with the pure antigen as immunoadsorbent. The purified antibodies were partially characterized by immunodiffusion and immunoprecipitin techniques. These antibodies could be used to study aspects of the muscle acylphosphatase structure, localization and other biological properties.
Ford EJ, Adam SE.In the horse, 5'-nucleotidase (5'-NT) activity is found mainly in homogenates of lung, kidney, small intestine, mammary gland, liver and pancreas. Lower activities are present in brain and muscle. Activity can be demonstrated histochemically in the glomeruli and tubules of the kidney, in the sinusoidal borders of the hepatocytes and the bile duct epithelium as well as in the blood vessels of all organs. There is no significant difference between the 5'-NT activity in serum and plasma of normal horses and of horses suffering from a range of orthopaedic conditions. Previous findings that gamma g...
Waldron-Mease E, Klein LV, Rosenberg H, Leitch M.Malignant hyperthermia developed in a 4-year-old Thoroughbred horse following 3 hours and 15 minutes of halothane anesthesia, with supplementary succinylcholine. Clinical signs included fever, sweating, hyperventilation, tachycardia, and decreased blood pressure followed by a rapid increase in blood pressure. Biochemical aberrations included hypocalcemia, hyperkalemia, hyperphosphatemia, myoglobinuria, and high creatine phosphokinase and ornithine carbamyl transferase activities. Treatment consisted initially of surface cooling with cold water, alcohol and ice, IV administration of cooled bala...
Hardy GW, Darbre A, Merrett M.3-Phosphoglycerate kinase was isolated from horse muscle and subjected to the action of cyanogen bromide. The resulting peptides were separated using gel filtration combined with either ion exchange chromatography on phosphocellulose in 6 M urea or high voltage paper electrophoresis. The sequence of the largest peptide, CB5, has been determined by a combination of automated and manual Edman degradation carried out on the intact peptide and derivatives obtained by proteolytic digestion. The isolation of two peptides derived from CB5 by cleavage of the bond between Asp109 and Pro110 facilitated ...
Klein L, Hopkins J.4-Aminopyridine was administered in incremental IV doses to healthy horses to evaluate cardiorespiratory and behavioral effects. Doses of 100 micrograms/kg produced apparent sensory discomfort, manifested by wiggling or curling of the lips and tongue, arching or stretching the neck, snorting, squealing, and coughing. At cumulative dosages of 300 to 500 micrograms/kg, muscle tremors, a stilted gait, and signs of excitement occurred. Once signs of excitement occurred, additional administration of 4-aminopyridine resulted in prolonged excitement consisting of severe muscle tremors and exaggerated...
Weaver BM, Webb AI.The halothane muscle/gas partition coefficients at 37 degrees C for 26 samples of eight different muscles from four horses were found to depend significantly on the fat content of the muscle sample with a regression coefficient of 1.913 (SEM 0.109) per per cent ether-extractable fat content. The blood/gas partition coefficients in 24 horses showed a significant dependence on plasma triglyceride concentration (regression coefficient 0.00084 (SEM 0.00033) per mg dl-1), an insignificant positive dependence on plasma free and total cholesterol concentration and, in a multiple regression analysis, ...
Snow DH, Baxter P, Rose RJ.An investigation into fibre composition and glycogen depletion pattern within the middle gluteal of 16 horses participating in an 80 km endurance ride was carried out. Although the proportion of slow twitch high oxidative (ST) fibres in the horses varied between 7 and 38 per cent, it was found that the horses with the highest proportion of these fibres usually had the best performance records. The cross-sectional area of the fast twitch low oxidative (FT) fibres was greatest, with the ST and fast twitch high oxidative (FTH) being similar in size. Most marked histological evidence of glycogen d...
Camici G, Manao G, Cappugi G, Ramponi G.We have predicted the secondary structure of horse muscle acylphosphatase by the statistical method of Chou and Fasman. In addition, we have studied the circular dichroism spectra of the enzyme, obtaining values for comparison to the predicted results. Discrepancies were found for the alpha-helix content estimated by the two methods.
Erber M, Geisel O.The prevalence of Sarcocystis spp. in horses was investigated in a survey at the Munich abattoir during 1978/79. Muscle specimens (oesophagus, diaphragm, sublingual muscle, myocardium) were examined using tryptic digestion. Out of 200 horses 31 (15.5%) were found to be carriers of sarcocysts. No parasites were found in the myocardium. In three animals sarcocysts could be isolated and differentiated in fresh preparations. Cysts with 5 to 11 microns by less than 0.5 microns hairlike, unstable protrusions were classified as Sarcocystis equicanis, whereas those with 2.5 to 4.5 microns by 0.8 to 1....
Hambleton PL, Slade LM, Hamar DW, Kienholz EW, Lewis LD.Four isocaloric diets containing 4, 8, 12 and 16% dietary fat (as soybean oil) were fed to four horses at four intervals according to a Latin square design. After 3 weeks of conditioning at each interval, diet effects were evaluated by trotting all horses at 3.2 m/sec for 6 hours. Pre- and posttrotting responses were measured in muscle and liver glycogen, serum long-chain fatty acids, serum electrolytes, serum enzymes, serum cholesterol, plasma glucose, packed cell volume and hemoglobin. Dietary fat was highly correlated with exercise-induced plasma glucose changes and with cholesterol concent...
Lindsay WA, McDonell W, Bignell W.Intracompartmental muscle pressures were recorded from the right and left forelimbs (extensor carpi radialis, triceps brachii) of healthy horses maintained in left lateral recumbency while under deep halothane anesthesia for 180 to 240 minutes. Cardiac output, blood pressure, blood gases, and acid-base status were monitored throughout the anesthesia, and electrolyte levels (Ca2+, P+, K+, Cl-, Na+) and enzyme activities (aspartate aminotransferase (AST), creatine phosphokinase (CPK), and blood lactate) were monitored for 7 days. Postanesthetic forelimb lameness was produced in 5 of the 6 horses...
Chacon-Arellano JT, Woolley DM.Smooth muscle cells are present in the tunica albuginea testis of the horse, pig and sheep. typical fusiform muscle cells constitute a distinct layer up to 0.3 micrometer thick in the horse; there are fewer muscle cells, mainly of the branched form, in the pig; whereas in the sheep the muscle component is least well developed, with some cells intermediate in form between smooth muscle cells and fibroblasts (myofibroblasts). Attention is drawn to the continuity of this capsular muscle with the smooth muscle associated with the vasculature of the spermatic cord in the horse. This association sug...
Stull CL, Albert WW.The percentages of three muscle fiber types in the biceps femoris and triceps brachii were determined in five breeds of horses: Belgians, Standardbreds, Thoroughbreds, Quarter Horses and Welsh ponies. Biopsies were taken from the two muscles from each of four 2-year-old untrained fillies of each breed. Percentages of red, white and intermediate fiber types were determined from tissues stained for succinic dehydrogenase activity. Intermediate fibers were the most numerous for all breeds. The difference between red and white fibers varied significantly with breed. Thoroughbreds had the highest p...
Benson GJ, Hartsfield SM, Manning JP, Thurmon JC.Succinylcholine chloride administered to horses anesthetized with halothane in oxygen and mechanically ventilated, caused slight but statistically insignificant (P less than 0.01) increases in creatine phosphokinase, lactic dehydrogenase, and aspartate aminotransferase activity. The increases in these enzymes have been explained on the basis of muscle damage resulting from succinylcholine chloride induced muscle fasciculations and by hypoperfusion of tissues due to depression of the cardiovascular system caused by general anesthesia. These changes were not clinically apparent based upon the ab...
Snow DH, Guy PS.Skeletal muscle of the equine was differentiated into three fibre types according to myosin ATPase (pH 9.4) and succinic dehydrogenase activity. The percentage of these types was determined in the musculus deltoideus, m triceps brachii caput longum, m gluteus medius, m semitendinosis, m biceps femoris and m vastus lateralis of the thoroughbred, Shetland pony, pony, heavy hunter and donkey. In addition the m gluteus medius was examined in the arab and American racing quarterhorse. High myosin ATPase activity fibres varied from a mean of 93.2 per cent in the m gluteus medius of the quarterhorse ...
Hanna CJ, Eyre P.Trimetaquinol [TMQ: 1-(3’,4‘,5’-trimethoxybenzyl)6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline hydrochloride] a potential p-sympathomimetic bronchodilator (Iwasawa & Kiyomoto 1967), has been shown to be an effective tracheal smooth muscle relaxant in guineapigs (Iwasawa & Kiyomoto 1967; Brittain 1972; Brittain et a1 1970, 1976) and an inhibitor of experimental bronchospasm in guinea-pigs and cats (Brittain et a1 1970; Brittain 1972). In addition, clinical studies with TMQ indicated that the drug was an effective bronchodilator in mild to moderate asthma (Yamamura & Kishimoto 1968). It may...
Snow DH.In the horse the effect of the adrenergenic agonists adrenaline, phenylephrine and salbutamol on haematocrit, plasma free fatty acid, glycerol and lactate levels were investigated. Effects on heart rate, sweating and muscle tremor were also studied. The effects of administration of the adrenoceptor antagonists propranolol, metoprolol, H35/25 and acepromazine on adrenaline-induced changes were examined. The results obtained with these agonists and antagonists suggest that the lipolysis and hyperglycaemia are mediated via beta-adrenoceptors. It appears that both beta1 and beta2 subtypes are invo...
Thornton JR, Lohni MD.Lactic dehydrogenase, although widely distributed in most tissues, was more highly concentrated in skeletal muscle, cardiac muscle, kidney and liver. Isoenzyme patterns showed a selective concentration of LDH5 in skeletal muscle while in the heart LDH 1 and 2 were predominant. In contrast, creatine kinase was only present in substantial concentration in skeletal and cardiac muscle. The serum concentrationof both enzymes showed a wide range of activity.
Henry RW, Diesem CD, Wiechers DO.Eleven ponies and 13 horses were used to develop a technique for determining conduction velocity for the radial and median nerves and establishing normal limits for these values. One pony was euthanatized to determine the course of the radial and the median nerves. From this dissection, both proximal and distal stimulation sites for the radial and the median nerves were selected, as well as areas for recording muscle evoked responses from the abductor digiti I longus (extensor carpi obliquus) and the radial head of the deep digital flexor muscles. The other ten ponies and the horses were used ...
Snow DH, Guy PS.Training and detraining had little effect on the activity of glycogen synthase, hexokinase, glycerol 3-phosphate dehydrogenase or total protein. The activity of 3-hydroxyacyl-CoA dehydrogenase increased markedly during training. After 5 weeks of detraining, the activity of 3-hydroxyacyl-CoA dehydrogenase was returning to pre-training values, whilst by 10-week detraining, the levels were increasing again.
Dodman NH, Waterman AE.The rapid intravenous administration of the butyrophenone tranquilliser, azaperone, at a dose rate of 0.29-0.57 mg/kg body weight resulted in the immediate onset of excitement and ataxia of varying degree in over half the animals. The severity of the reaction appeared to be related to the size of the animal. Other side effects such as salivation, sweating, muscle tremor and vocalisation were also observed. The possible causes of this paradoxical reaction to the tranquilliser are discussed.
Stefani M, Berti A, Camici G, Manao G, Cappugi G, Ramponi G.The use of sodium selenite as a catalyst in the presence of oxygen was a suitable technique to obtain in good yield an interchain S-S dimeric form of horse muscle acylphosphatase. The dimer so obtained possesses kinetic properties very similar to those of the native enzyme. On the other hand the dimer has shown a generally lower stability in respect of the thermal inactivation, particularly in the acidic environment, to the lyophilization and to the proteolytic attack. As regards the 8 M urea inactivation, the dimer is not able to completely regain its activity by dilution, showing a behaviour...
Quist EE, Hokin LE.A potent inhibitor of (Na+ + K+)-ATPase activity was purified from Sigma equine muscle ATP by cation- and anion-exchange chromatography. The isolated inhibitor was identified by atomic absorption spectroscopy and proton resonance spectroscopy to be an inorganic vanadate. The isolated vanadate and a solution of V2O5 inhibit sarcolemma (Na+ + K+)-ATPase with an I50 of 1 micrometer in the presence of 1 mM ethyleneglycol-bis-(beta-aminoethylether)-N,N'-tetraacetic acid (EGTA), 145 mM NaCl, 6mM MgCl2, 15 mM KCl and 2 mM synthetic ATP. The potency of the isolated vanadate is increased by free Mg2+. ...
Johnson JH, Amend JF, Franklin D, Garner HE.Ultrasonic dimension gauges were implanted in the crico-arytenoideus dorsalis muscle in a mature horse. Resting and contracted muscle length and average contraction rate were measured serially in the conscious state over a period of 25 days. Results suggest that specific laryngeal muscle function in the horse may be defined with this approach. Since man and horse are both known to suffer from laryngeal hemiplegia, this experimental preparation may help provide information of benefit to both species.
Aleman M, McCue M, Bellone RR.Fatal anesthesia-induced malignant hyperthermia (MH) and rhabdomyolysis with hyperthermia documented in Quarter Horses (QH) breeds are caused by a missense variant in the ryanodine receptor 1 gene (RYR1: XP_023505430.1.:p.(R2454G), designated as MH). The reported cases to date have all been heterozygous, and the allele frequency is suspected to be low. Objective: To determine an accurate estimate of MH allele frequency in multiple horse breeds and investigate whether homozygous animals exist in the population. Methods: In total, 159 227 horses from 16 breeds who were either submitted for cli...
Connysson M, Jansson A.It is generally accepted that plasma muscle enzyme activity of creatine kinase (CK) and aspartate aminotransferase (AST) may increase in racehorses after exercise and racing, indicating muscle fibre damage and/or increased leakage from muscle fibres. However, other studies suggest that starch intake might influence plasma muscle enzyme activity reported postexercise. This study aimed to evaluate the effect of different starch allowances on plasma muscle enzyme activity in Standardbred trotters in professional training. Seventy-six horses from five professional trainers were sampled pre- and po...
Ding W, Gong W, Bou T, Shi L, Lin Y, Shi X, Li Z, Wu H, Dugarjaviin M, Bai D.Copy number variation (CNV) is an important source of genetic variation. However, studies utilizing whole-genome sequencing to investigate CNVs in horse populations and their effects on traits remain relatively limited. This study aims to address the lack of research on the impact of copy number variation (CNV) on racing performance in horse populations, providing new insights for locally bred racing breeds. We analyzed 60 offspring derived from the crossbreeding of Thoroughbred horses and Xilingol horses. These horses were temporarily named "Grassland-Thoroughbred" and were divided into two g...
Domino M, Borowska M, Stefanik E, Domańska-Kruppa N, Skibniewski M, Turek B.In equine surface electromyography (sEMG), challenges related to the reliability and interpretability of data arise, among other factors, from methodological differences, including signal processing and analysis. The aim of this study is to demonstrate the filtering-induced changes in basic signal features in relation to the balance between signal loss and noise attenuation. Raw sEMG signals were collected from the quadriceps muscle of six horses during walk, trot, and canter and then filtered using eight filtering methods with varying cut-off frequencies (low-pass at 10 Hz, high-pass at 20 Hz...
Avison A, Physick-Sheard PW, Pyle WG.This paper reviews the myocardial substrate of horses relative to that of humans and discusses the utility of performance horses as a model of exercise-associated cardiac arrhythmias and sudden cardiac death in athletes. The coronary circulation is similar between the species while coronary artery anomalies and myocardial bridging appear to only be associated with athletic mortality in human athletes and not in performance horses. There are subtle differences in the histology of the sinus and atrioventricular nodes, of unknown clinical significance, while the His bundle is more highly innervat...
Bauquier J, Takahashi C, Rosales C, Pitt J.There is limited published information on Malva parviflora toxicosis in horses. Four previously reported cases all resulted in death or euthanasia. The aim of this cluster investigation was to describe historical, clinical and clinicopathological findings of four ponies with suspected M. parviflora toxicosis and compare these to previously reported cases. Historical, clinical and clinicopathological findings were collated. Ponies were grazing pasture of approximately >90% M. parviflora. Pony 1 died rapidly without veterinary examination. Pony 2 was examined for prolonged recumbency attribut...
Simões J, Santos AM, Santos C, Silva AS, Vintém C, Fonseca J, Coelho C.Show jumping is a popular and complex equestrian modality practiced by a athletes of different levels. However, most studies focus on elite athletes. Objective: The aim of this work was to assess the effect of a show jumping test (SJT), designed for novice athletes, on the physiological biomarkers and energy indexes of a group of horses, bred and trained in Portugal. Methods: In this prospective cross-sectional study, thirteen horses and their riders performed a SJT with obstacles set at 80 cm height using a heart rate monitor (M430 with H10 sensor). Physical examination and blood samples, for...
Liu Y, Liu Y, Bai D, Dugarjaviin M, Zhang X.Skeletal muscle satellite cells are muscle stem cells that play an important role in the growth, development, and repair of skeletal muscle as well as in the locomotor performance of the animal body. Lysine is the first limiting amino acid and is involved in multiple metabolic pathways in the organism to maintain overall physiological requirements. In this study, Mongolian horse satellite cells were cultured using lysine culture solution at different concentrations, and the proliferative capacity of satellite cells was detected by the cck-8 assay, and the optimal culture concentration was sele...
Zhang X, Liu Y, Ma W, Li L, Bai D, Dugarjaviin M.Mongolian horses are renowned for their remarkable endurance and ability to adapt to harsh environments. To delve deeper into the molecular mechanisms that underlie these traits, researchers conducted a comprehensive analysis of transcriptomic and proteomic changes in Mongolian horses at three distinct time points: before, immediately after, and 24 h following a 20 km run. The transcriptomic analysis uncovered significant variations in gene expression patterns across these time points. Specifically, 291 differentially expressed genes (DEGs) were identified when comparing pre-exercise to post-e...
Gong W, Ding W, Bou T, Shi L, Lin Y, Shi X, Wu H, Li Z, Dugarjaviin M, Bai D.Ferulic acid (FA), a natural antioxidant and major active component in Angelica sinensis, has beneficial effects on skeletal muscle health; however, its role in modulating muscle fiber type composition Mongolian horse remains unclear. In this study, we found that FA promotes the proliferation of Mongolian horse skeletal muscle satellite cell (MuSCs), upregulates the expression of fast-twitch muscle marker genes (e.g., MYH2), and downregulates the expression of slow-twitch markers (e.g., MYH7). RNA-seq revealed that FA activates the HIF-1 signaling pathway, significantly increasing PDK1 express...
Ding W, Gong W, Bou T, Shi L, Lin Y, Shi X, Li Z, Wu H, Dugarjaviin M, Bai D.The core objective of racehorse breeding is to enhance the speed and endurance of the horses. The Grassland-Thoroughbred is an emerging horse breed developed in northern China in recent years, characterized by excellent speed performance, enduring stamina, and strong environmental adaptability. However, research on the genetic characteristics within this breed and the genes associated with athletic performance remains relatively limited. We conducted whole-genome resequencing of Grassland-Thoroughbred F1, F2, F3, and the crossbred population (CY) and obtained a total of 4056.23 Gb of high-qual...
Frontiers in geneticsJuly 18, 2025
Volume 16 1630614 doi: 10.3389/fgene.2025.1630614
Gong W, Ding W, Bou T, Shi L, Lin Y, Shi X, Li Z, Wu H, Dugarjaviin M, Bai D.Ferulic acid (FA), a natural antioxidant, has attracted considerable attention for its regulatory potential in skeletal muscle development, energy metabolism, and muscle fiber type transformation. Unassigned: This study established a research system based on Mongolian horse skeletal muscle satellite cells to elucidate the molecular basis by which ferulic acid regulates muscle fiber type transformation through a non-coding RNA interaction network. Unassigned: A total of 18 differentially expressed miRNAs (DEMIRs) and 128 differentially expressed lncRNAs (DELs) were identified through transcript...
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...
Calatayud-Bonilla M, Carmona JU, Prades M.Myofascial pain syndrome (MPS) is caused by trigger points (TrPs): hypersensitive spots in taut muscle bands that impair function and cause pain. Dry needling (DN) is a common treatment in humans, but evidence in horses is limited. This prospective, controlled study evaluated the effectiveness of DN in reducing TrP-related pain in the brachiocephalic muscle of horses. Of the 98 horses enrolled, 66 were allocated to a treatment group receiving weekly DN sessions for three weeks, while 32 were assigned to a control group with no intervention. Pain and function were assessed using pressure algome...
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,...
Jastrzębska E, Dobbek D, Pawłowska A.Back pain in horses is a frequent musculoskeletal issue that affects performance and welfare. Magnetotherapy has been proposed as a complementary, non-invasive treatment to reduce pain and support soft tissue recovery, but studies in horses remain limited. This pilot study aimed to evaluate the effects of low-frequency pulsed magnetic field therapy on horses with hypersensitivity to palpation along the longissimus dorsi muscle. Four recreational horses participated in a 10-session magnetotherapy program, with changes assessed using palpation, neck flexibility tests, heart rate measurements and...
Libak Haugaard S, Schneider MJ, Nissen SD, Saljic A, Fruergaard Andersen P, Carstensen H, Hopster-Iversen C, Jespersen T, Larsen S, Buhl R.Mitochondrial respiration sustains the high energy demands of endurance exercise, yet the extent to which atrial, ventricular, and skeletal muscle mitochondria adapt remains uncertain. At the same time, endurance athletes face an increased risk of atrial fibrillation (AF), but the role of cardiac metabolism in arrhythmia susceptibility is poorly understood. Here, we compared mitochondrial respiration in skeletal muscle and across all four cardiac chambers between trained and untrained racehorses ( = 34) to investigate adaptations associated with long-term endurance exercise. We further examine...
Yuan X, Yao X, Zeng Y, Wang J, Ren W, Wang T, Li X, Yang L, Yang X, Meng J.The effects of physical exercise on protein expression and metabolites in the plasma exosomes of horses are not yet clear. This study aims to elucidate the effects of exercise training on the expression of plasma extracellular vesicle proteins and metabolites in horses through multi-omics analysis, providing reference indicators for the training and performance evaluation of horses. Methods: Eight healthy 3-year-old horses were selected for the study, with four untrained horses as the control group and four trained horses as the training group. After conducting proteomic and metabolomic an...
Shan D, Yao X, Ren W, Huang Q, Su Y, Li Z, Li L, Wang R, Ma S, Wang J.Whole-genome bisulfite sequencing (WGBS) was employed in this article to map blood DNA methylation profiles at single-base resolution in Yili horses before a 5000 m speed race, with comparative analysis of epigenetic differences between the 'elite group' and 'ordinary group' across six four-year-old stallions. The overall methylation level in the elite group was generally higher than that in the ordinary groups, with a minority of regions showing hypomethylation. For instance, the promoter regions of key metabolic and neuro-related genes exhibited significant hypomethylation. The article ident...
Shahid MA, Guitart AS, Bertin FR, Simon O, Ceusters J, Serteyn D, Whitworth DJ.A minimally invasive microbiopsy-based method for the isolation of mesenchymal stem cells (MSCs) from equine skeletal muscle (M-MSCs) provides a readily accessible source of MSCs for clinical applications. We examined the expression of genes associated with immunomodulation and anti-inflammatory pathways, in addition to those of growth factors and the major histocompatibility complex (MHC) molecules I and II, at constitutive levels and after priming with inflammatory cytokines, an immunostimulant, and heat-shocking. While there was notable variation between the M-MSCs from each of the horses i...
Boger B, Naraian M, Hernandez E, Eaton A, Rockburn R, Tillman I, Payne S, Yob C, Panek C, Manfredi JM.Resistance bands used while horses are exercised with their handlers have shown benefits, but it is unknown if whole-body resistance bands used independently have therapeutic benefits. This study hypothesized that horses with varying gait asymmetries would experience improvements in lameness, muscular function, range of motion, posture, and cortisol following short-term use of a whole-body resistance band wrap (RBW). In this study, nine lame adult horses were evaluated with and without the RBW. The assessment included: objective gait analysis, acoustic myography, postural analysis, gait kinema...
Mukai K, Takahashi Y, Ebisuda Y, Sugiyama F, Yoshida T, Miyata H.This study tested the hypothesis that 6 weeks of high-intensity interval training (HIIT) would induce greater physiological adaptations than moderate-intensity continuous training (MICT) in Thoroughbred horses. Seven untrained horses completed two distance-matched treadmill training protocols (three sessions per week) in a randomized crossover design, separated by a three-month washout: MICT (6 min at 70% ) and HIIT (6 × [30 s at 100% with 30 s at 30% ]). Incremental exercise tests were conducted at weeks 0, 3, and 6 to assess exercise performance and physiological responses. M...
Campos Schweitzer A, Mespoulhes-Rivière C, Perkins JD, Ducharme NG, Piercy RJ, Lynch N, Rossignol F.To evaluate functional and histopathologic outcomes of standing selective laryngeal reinnervation using the spinal accessory nerve (SAN) in horses with experimentally induced recurrent laryngeal neuropathy (RLN). Methods: Five Thoroughbred mares. Methods: Prospective cohort study. Methods: The horses underwent left recurrent laryngeal neurectomy followed 8 weeks later by selective laryngeal reinnervation using the SAN. Follow-up evaluations at 4.5, 6, 8, and 12 months included treadmill exercising endoscopy, ultrasonography of intrinsic laryngeal muscles, and percutaneous electrical stimul...
Lenarz J, Smit IH, Rhodin M, Lischer C, Fugazzola MC.Intramuscular vaccination is a routine component of equine medicine, but local muscle soreness may transiently affect gait symmetry. Objective data on vaccination-associated gait changes in horses are lacking. Objective: To investigate whether intramuscular vaccination induces measurable gait asymmetries depending on injection site, to inform recommendations on vaccination site selection and short-term exercise management. Methods: In this prospective, randomised, blinded, placebo-controlled study, eighteen clinically sound Warmblood horses were enrolled and received an intramuscular vaccinati...
Billmann P, Durham A, Christen G, Savioli G, Gross JJ, Gerber V, Fouché NE.Limited published data are available regarding the relationships among clinical signs associated with pituitary pars intermedia dysfunction (PPID), age, and concentrations of proopiomelanocortin-derived peptides and cortisol. Objective: Identify clinical signs associated with age, beta-endorphin (β-END), adrenocorticotropic hormone (ACTH), and cortisol concentrations and compare β-END and cortisol concentrations between horses with PPID and geriatric controls. Methods: A total of 113 horses aged 18-32 years. Methods: Cross-sectional study. Clinical signs were scored, plasma β-END, ACTH, an...
Slavik K, Underwood C, Lowndes C, Skelton G, van Eps A.To examine the effects of botulinum toxin inoculation into the deep digital flexor (DDF) muscle on foot biomechanics. Unassigned: 6 healthy horses were injected with botulinum toxin in the DDF of 1 forelimb. The opposite forelimb was untreated. Ground reaction forces (GRF) were measured using a pressure sensor in regions of interest, including the dorsal hoof wall (toe). The location of the center of pressure (COP) was measured relative to the dorsal hoof wall during static standing and at peak stance during walking. Repeat measurements 3, 7, 14, 28, and 42 days after injection were compared t...
Li X, Qian S, Yang L, Yang X, Chang X, Zeng Y, Meng J.This study aimed to investigate the relationship between genes and metabolites involved in glycogen metabolism across different tissues of Yili mares using joint transcriptomic and metabolomic analyses. Glycogen content was measured in various tissues (pincer, trapezius, latissimus dorsi, gluteus medius, semitendinosus, external abdominal obliques, liver, and heart) from seven Yili mares. The liver, as the visceral tissue with the highest glycogen content, and the gluteus medius, as the muscle with the highest glycogen content, were selected for transcriptomic sequencing and metabolomic analys...
Nascimento C, Braz AL, Barbosa I, Freire G, Nicolau M, Silvestre F, Filho HM, Simões J, Estepa JC, Clayton H, Coelho C.This study aimed to investigate cardiac adaptations and energy expenditure of jumping horses after water treadmill (WT) training. Six trained horses were evaluated before (PRETR) and after (TR) a WT training (20 min, twice/week, water at carpus height) for 10 weeks. Transthoracic echocardiography was performed at PRETR and TR with phased array transducer (1.9-4 MHz) to obtain interventricular septal thickness (IVS), LV internal diameter (LVID), and posterior wall thickness (LVPW) at end-diastole (d) and systole (s) and heart rate (HR). Left ventricule end diastolic volume (Vd) and end syst...
Freitag GP, de Lima LGF, Kozicki LE, Souza FA, Nogueira E, Ribeiro LB.This study investigated the influence of morphometric characteristics on performance in Quarter Horses competing in barrel racing. Methods: A total of 125 horses were assessed using 28 linear and angular body measurements derived from standardized left-side photographs captured via smartphone and analyzed with open-source software. Results: Measurements were subjected to exploratory factor analysis, extracting six principal components (forequarters, hindquarters, midsection, posterior angles, scapular traits, age and weight), which together explained 83.0 % of the morphological variance. Foreq...
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...
