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.
Lindholm A, Piehl K.LINDHOLM, ARNE and KARIN PIEHL: Acta vet. scand. 1974, , 287–309. — Measurements of metabolites, electrolytes, water, RNA and protein concentrations, the activity of certain muscle enzymes (SDH and PFK) and muscle fibre composition were made on biopsy specimens from the gluteus medius muscle of 68 standardbred horses, ½ to 8 years old. The muscle fibres were classified in 3 major categories, slow twitch (ST), fast twitch and high oxidative (FTH) and fast twitch (FT) fibres. The percentage of FTH fibres was higher after the age of 4 years, averaging 54 %. ST fibres comprised 24 % and this...
Lindholm A, Saltin B.LINDHOLM, ARNE and BENGT SALTIN: The physiological and biochemical response of standardbred horses to exercise of varying speed and duration. Acta vet. scand. 1974, 15, 310–324. — Welltrained standardbred horses were studied to examine the metabolic response to excercise of various speeds and duration. Comparisons between interval (400, 700, 1,000 and 2,000 m) and continuous trotting (1 hr., 2 hrs.) and racing were made. Muscle and rectal temperatures were recorded before and immediately after each work bout. Heart rate was linearly related to trotting speed, and maximal heart rate (240 be...
Gunn HM.The research article is a study about neurogenic atrophy in the dorsal cricoarytenoid muscle of horses. It examines whether this condition is present prenatally in horses and studies the patterns [...]
Yamaguchi M, Miyazawa Y, Sekine T.Myosin was prepared from smooth muscle of horse esophagus in good yield
(about 15 ° mg/Ioo g tissue) and was designated myosin S. Its properties were compared
with those of myosin A from skeletal muscle.
The ratio of the absorption of myosin S at 280 nm to that at 26o nm was about
1.8, and the amount of contaminating phosphorus was only o.91 g/io 5 g of myosin S,
indicating that the latter is free of nucleic acid. The purity of this protein was examined
by ultracentrifugation, gel filtration in the presence of 0.5 M KC1 and 6 M urea and
chromatography on DEAE-cellulose columns. These e...
Van den Oord AH, Wesdorp JJ, Van Dam AF, Verheij JA.In commercial samples of equine myoglobin and samples of equine and bovine myoglobin prepared in the laboratory, a small amount of the protein was present as an aggregate. The presence of the myoglobin aggregate could be demonstrated by gel filtration on Sephadex G-100 Superfine, which also provided a means of isolating it. Gel filtration on Sephadex G-100 showed the molecular weights of the equine and bovine moyglobin aggregates to be about 35000 and 34000 respectively, thus supporting the hypothesis that they are dimers. This was confirmed for the equine myoglobin by ultracentrifugation meas...
AZZONE GF.In a series of model reactions, it is shown that residues
of ~-aminoacids may be inserted by a particular rearrangement into certain carboxyl or carbonylamido
groups. Repeated insertion results in the formation of
a peptide derivative. It is concluded that natural peptides or proteins must not necessarily be formed by head
to tail combination of aminoacids, Other implications of
the new principle are discussed.
The study investigates the case of an Australian Quarter Horse suffering from Polysaccharide Storage Myopathy (PSSM), a muscular disease commonly seen in Quarter Horse breeds, Warmbloods, and draft horses. This [...]
To evaluate the effect of hippotherapy (physical therapy utilizing the movement of a horse) on muscle activity in children with spastic cerebral palsy. Methods: Pretest/post-test control group. Methods: Therapeutic Riding of Tucson (TROT), Tucson, AZ. Methods: Fifteen (15) children ranging from 4 to 12 years of age diagnosed with spastic cerebral palsy. Methods: Children meeting inclusion criteria were randomized to either 8 minutes of hippotherapy or 8 minutes astride a stationary barrel. Methods: Remote surface electromyography (EMG) was used to measure muscle activity of the trunk and upper...
Many colic horses are compromised due to the disease state and from hours of starvation and sometimes long trailer rides. This could influence their muscle energy reserves and affect the horses' ability to recover. The principal aim was to follow metabolic parameter before, during, and up to 7 days after anaesthesia in healthy horses and in horses undergoing abdominal surgery due to colic. Methods: 20 healthy horses given anaesthesia alone and 20 colic horses subjected to emergency abdominal surgery were anaesthetised for a mean of 228 minutes and 183 minutes respectively. Blood for analysis o...
López-Císcar C, Ibáñez-López A, Rivero JLL, Harris P.This report describes the nutritional management of an 18-year-old, 553 kg gelding warmblood used for dressage lessons that presented with severe weight loss, marked muscle atrophy, poor dentition, sabulous urolithiasis, gastric ulcers, and later small colon impaction. On admission, the diet consisted of ad libitum wheat straw and mixed cereals (73:27 forage:concentrate), providing 2% of body weight as dry matter without vitamin-mineral supplementation. Marked deficiencies were identified in digestible energy (38%), crude protein (20%), lysine, threonine, vitamins, and minerals, while sugar an...
Harrison LM, St George LB, Goff LM, Nardese G, Barnes T, Ahern B, Sole-Guitart A.Equine back rehabilitation commonly integrates dynamic mobilization exercises (DME), including DME to the chest (DMEChest) and DME to the hip (DMEHip), and therapeutic trunk (TTE) exercises, including pelvic rounding (Rounding), and lateral tail pulls (LatTail). However, limited evidence supports their use for selectively activating trunk muscles. Objective: To quantify and compare superficial epaxial and hypaxial muscle activity during selected DMEs and TTEs using surface electromyography (sEMG). Increased muscle activity was hypothesized across exercises, specifically in external abdominal o...
Geng A, Wang X, Li L, Cowie S, Bai D, Dugarjaviin M, Zhang X.The scientific evidence regarding the use of plant-derived extracts to alleviate exercise-induced muscle damage in horses remains limited. Mulberry leaf flavonoids (MLFs) are the primary bioactive constituents of a traditional medicinal plant and are potent antioxidants. The aim of this study was to investigate the protective effects of MLFs against exercise-induced muscle damage. In this study, twelve Mongolian horses were used in a 3 × 3 Latin square design to investigate the protective effects of MLFs. Our results showed that high-intensity exercise negatively impacted the immune status, m...
Serteyn D, Graide H, Ceusters J, Vandersmissen M, Salciccia A, Sandersen C, Lejeune JP.Mesenchymal stromal/stem cells (MSCs) are increasingly investigated as intra-articular therapies for equine osteoarthritis (OA), although most studies have focused on allogeneic or combination-based approaches. Evidence supporting the use of autologous MSCs as a stand-alone treatment remains limited. The present study evaluated the safety and clinical evolution following intra-articular administration of autologous muscle-derived MSCs (mdMSCs) in horses with naturally occurring chronic OA. Thirteen horses with confirmed clinical disease were included. Each affected joint received a single inje...
Ribeiro G, Agrícola R, Sanchez MMF, Ramos FR, Borges J, Abrantes J, Prazeres J.To evaluate the feasibility of a hand-held myotometry device for measuring the biomechanical parameters (frequency, stiffness, and decrement) of the longissimus dorsi muscle in the thoracolumbar region of healthy horses. Unassigned: Data were obtained from 50 adult horses. The biomechanical parameters were measured using a MyotonPRO device in triple-scan mode. Measurements were recorded on both sides, with the horses standing square. The analysis focused on whether there were differences between the sides and correlations between the variables. Unassigned: The mean muscle frequency (hertz) was...
Scheibenpflug M, Haussler KK.Equine lameness diagnosis is dominated by a joint- and tendon-centric paradigm. The standard diagnostic algorithm relies on gait observation, perineural and intrasynovial anesthesia, and cross-sectional imaging. It is directed almost exclusively at skeletal and articular structures. Myofascial trigger points (MTrPs) are hypersensitive, hyperirritable loci within taut bands of skeletal muscle. They produce local and referred pain on compression or contraction. In horses, MTrPs are a clinically relevant but systematically overlooked source of primary lameness. This review synthesises evidence fr...
Kósa CA, Szenci O, Lénárt L, Biksi I, Szép R, Keresztesi Á, Mircean M, Taulescu M, Kutasi O.To investigate the pathophysiology, prevalence and severity of equine exertional rhabdomyolysis in a mountainous region of Transylvania, Romania, this study considered genetic and histological factors. We determined the occurrence and frequency of a mutation in the glycogen synthase gene 1 (GYS1), associated with equine polysaccharide storage myopathy type 1 (PSSM1), in two adjacent populations, one with a significantly high prevalence of the disease (high altitude villages, HV) and the other with a rare prevalence (valley villages, VV). We genotyped GYS1 in 41 animals (HV = 31, VV = 10) and f...
Nascimento C, Santos C, Walton M, Gonçalves T, Freire G, Nicolau M, Silvestre F, Simões J, Borges J, Pires N, Filho HM, Clayton H, Coelho C.The correct prescription of aquatic treadmill training for equine athletes depends on understanding the muscular changes generated by working in the water. Objective: The aim of this study was to test the hypothesis that the inclusion of a water treadmill in a routine training protocol would alter muscle mass of show jumping horses. Methods: Six fit-to-compete horses were trained for 10 weeks with a water treadmill (twice a week, 20 minutes, water level at the carpus), in addition to regular physical exercise. Body composition, infrared thermography (IRT) of propulsive muscles (m. brachiocepha...
Liu Y, Wang X, Gong S, Dugarjaviina M, Zhang X.This study aims to conduct a comparative analysis of the quality and flavor of meat from four categories of Mongolian horses (Wushen, Baicha, Barhu, and Ujimqin). Physicochemical indicators, electronic nose, electronic tongue, and lipidomics were used to characterize meat quality and flavor and to screen for differential markers. Results showed that Wushen Horses had the highest pH, serine, glutamic acid, total free amino acids (∑FAA), total non-essential amino acids (∑NEAA), total amino acids (∑TAA), NEAA/TAA, W2S sensor response, umami and richness values, and had the lowest cooking lo...
Sun W, Shen Z, Cairen D, Luo P, Yao X, Meng J, Zeng Y.Body measurement traits are a direct production indicator reflecting growth status and guiding genetic selection. Identifying molecular markers associated with body measurement traits could accelerate animal breeding programs. The Yanqi horse, an important indigenous breed in Xinjiang, is primarily distributed in the Bayingolin Mongol Autonomous Prefecture. However, molecular markers linked to body measurement traits in Yanqi horses remain uncharacterized. In the present study, whole-genome resequencing was performed on 183 Yanqi horses, yielding 13,366,672 single-nucleotide polymorphisms (SNP...
Dockalová H, Zalesakova D, Batik DB, Batik A, Kacetlova D, Horky P.Physiological adaptation to training in young sport horses remains incompletely characterized, particularly during standardized preparation for breeding licensing. Objective: The aim of this study was to evaluate cardiovascular and plasma biochemical responses to acute exercise and long-term training in three-year-old Czech Warmblood stallions during standardized free jumping exercise. Methods: Thirteen Czech Warmblood stallions were monitored over a 112-day training period. Heart rate parameters (minimum, maximum, and mean) were recorded during standardized free jumping tests. Plasma biochemi...
Liu Y, Wang X, Tan G, Dugarjaviina M, Zhang X.Horse meat is a high-quality protein source. A total of 50 two-year-old male horses with similar body weights (300 ± 50 kg) were used: 30 for regional comparison (10 each from Bulgan province region of Mongolia (BPM), Tuv province region of Mongolia (TPM), and Inner Mongolia region of China (IMC)) and an additional 20 from the IMC region for muscle-site analysis. To elucidate the molecular mechanisms underlying regional and muscle-site differences in the meat quality of Mongolian horses, with particular emphasis on tenderness, this study analyzed chemical composition, minerals, fatty acids, a...
Nascimento RCMD, Guedes EAB, Silva RBD, Cerqueira ITI, Freire CCDS, Câmara DR, Moura FA, Escodro PB, Goulart MOF.Vaquejada (VQ) is a traditional Brazilian sport demanding high performance from Quarter Horse (QH) athletes. This study aimed to identify modifications in hematological, biochemical, inflammatory, and oxidative stress biomarkers associated with VQ training, comparing conditioned and non-conditioned horses. Blood samples were collected at rest from 70 healthy QH horses: 60 athletes (VQ-conditioned athlete group-AG) and 10 sedentary controls (breeding horses-CG). Using Linear Mixed Models alongside comprehensive hematological and biochemical analyses, the study found that AG horses exhibited an ...
Li Z, Ren W, Wang R, Li L, Ma S, Su Y, Shan D, Huang Q, Wang J.Although the Kazakh horse is a dual-purpose breed renowned for both milk and meat production, the extent to which surgical castration alters gene expression in its muscles has not yet been fully elucidated. In this study, left longissimus dorsi muscle (LDM) samples were obtained from six Kazakh stallions (W group) and six Kazakh geldings (S group) to comparatively evaluate meat quality parameters, examine histological characteristics in tissue sections, and apply transcriptomic profiling to comprehensively explore the principal regulatory pathways and candidate genes through which surgical cas...
Bou T, Ding W, Gong W, Li Z, Shi X, Dugarjaviin M, Bai D, Yang L.The Grassland Xichun horse is an emerging crossbred population developed from Xilingol mares and Thoroughbred stallions in Inner Mongolia, China, yet its blood physiological profile has not been systematically characterized. In this study, we compared 32 hematological and serum biochemical parameters between 177 Grassland Xichun horses and 35 Xilingol horses maintained under the same extensive grazing conditions. Following Benjamini-Hochberg FDR correction, 17 of 32 parameters differed significantly between breeds. Grassland Xichun horses showed markedly higher RBC count (9.145 vs 7.905 × 10...
Wesolowski LT, Artman JL, Semanchik PL, Carson CP, Fenger CK, Pagan JD, Valberg SJ, White-Springer SH.Recurrent Exertional Rhabdomyolysis (RER) is a skeletal muscle disease that can intermittently impede careers of equine athletes. Manifesting as episodes of muscular stiffness and degeneration, RER causes lost training and competition days. RER is associated with abnormal intracellular calcium (Ca) regulation. Calcium released from the sarcoplasmic reticulum to initiate contraction may also be transported into mitochondria, which impacts energy production. RER-susceptible horses exhibit down-regulated mitochondrial proteins but upregulated mitochondrial genes. Thus, mitochondrial function may ...
Takahashi K, Mukai K, Shirai T, Ebisuda Y, Sugiyama F, Yoshida T, Hatta H, Kitaoka Y.This study investigated whether different pacing patterns during high-intensity exercise elicit distinct transcriptional responses in equine skeletal muscle. Eight Thoroughbred horses completed two treadmill exercise sessions in a randomized crossover design. In the positive-pacing condition, horses exercised at 110% maximal O₂ uptake (V˙O₂max) for 1 min followed by 90% V˙O₂max for 1 min, whereas in the negative-pacing condition, the order was reversed. At 4 h after exercise, the positive-pacing protocol resulted in upregulation of 1,989 genes and downregulation of 840 genes, whereas t...
Tomaini MC, Heck DPO, Moreira BC, Lima LR, Marson RA, Almeida FQ.This study aimed to evaluate electromyographic and kinematic parameters of the thoracic and pelvic limbs of horses at a walk and trot on a treadmill. Eleven Brazilian Sport Horses trained for Eventing were assessed in a completely randomized design under two conditions: walk (1.8 m/s) and trot (3.6 m/s). Horses were evaluated on a high-speed treadmill using surface electromyography (sEMG) and kinematic analysis. sEMG was performed bilaterally on the mm. extensor carpi radialis and mm. flexor carpi ulnaris; bilateral muscles of the pelvic limb: mm. tensor fascia latae and mm. biceps femoris u...
Xue Y, Luo P, Shen Z, Meng C, Yao X, Meng J, Ren W, Wang T, Zeng Y.Training induces sweat morphology changes in horses from muddy sweat (MS) to foamy sweat (FS) and clear sweat (CS), reflecting physiological adaptation. However, the metabolic mechanisms linking sweat phenotypes to systemic amino acid dynamics remain unclear. This study integrated sweat untargeted metabolomics and plasma amino acid targeted metabolomics to reveal coordinated metabolic remodeling. Six 2-year-old horse stallions underwent 10-week training. Plasma and sweat were sampled pre- and post-race at each stage. LC-MS/MS and UHPLC-MS/MS were used for sweat metabolome and plasma amino aci...
Scheibenpflug M.In-hand training of piaffe and passage via tactile leg stimulation (Handarbeit mit Touchieren) is widely practised in dressage, yet consistently produces horses that elevate their legs without achieving collection - a pattern termed Schenkelgänger (leg-movers) in classical German equitation. Based on published kinetic, kinematic, and electromyographic literature, this review argues that tactile leg stimulation activates the spinal nociceptive withdrawal reflex, an unloading movement mechanistically opposed to the elastic tendon rebound and ventral muscular chain activation that define true co...
Dubey JP, Gupta A, Rosenthal BM.Uncertainty shrouds the number and identity of the species of Sarcocystis infecting horses in the United States. Horses are intermediate hosts for Sarcocystis fayeri, for which the domestic dog is the definitive host. Clinical signs and lesions associated with S. fayeri are not defined. Granulomatous myositis, especially involving the chest and dysphagia, is one of the clinical presentations associated with S. fayeri infections. Whether S. fayeri is the sole species that forms sarcocysts in equine muscles in the United States is not clear. Little is known of the molecular diagnosis of Sarcocys...
Watson SL, Davis ZG, Koch DW, Connard SS, Brown AC, Schnabel LV, Fisher MB.To examine regional mechanical and biochemical differences across the length of the equine superficial digital flexor tendon (SDFT). Unassigned: Equine SDFTs were collected postmortem from 9 donors and divided into proximal, middle, and distal regions based on the location of the musculotendinous and osteotendinous junctions. Tensile testing was performed on samples to obtain macroscale mechanical properties, and atomic force microscopy was done to obtain microscale mechanical properties. Biochemical assays and histological staining were done to assess glycosaminoglycan (GAG), collagen, and DN...
Meyer HL, Tang Y, Wang Y, Kingston JK, Brown JA, Sides RH, Bayly WM.To document changes in acid-base and ion balance during exercise following furosemide administration and to relate them to performance. Unassigned: 6 fit Thoroughbred horses received 0.5 mg/kg IV furosemide (F) or a placebo (C) in randomized crossover order 4 hours before galloping to fatigue on a treadmill at the speed equated with an oxygen demand of 1.15 X maximum oxygen consumption (V˙o2max). Arterial and mixed venous blood was sampled before treatment, preexercise, after 2-minute warm-up, at fatigue, and 1 minute postexercise. The pH, temperature-corrected Pco2, total CO2, and sodium, po...
Beaussart M, Perrin R, Marunova E, Moraine F, Fourteau D, Blake R.We aimed to investigate the effects of an 8-week 448 kHz radiofrequency (RF) on multifidus cross-sectional area (CSA) and thoracolumbar differential range of motion (ROM). Eight Thoroughbred horseball horses received four RF treatments (T9-L6) at 2-week intervals. Multifidus CSA (T10-L5) and differential spinal ROM between the withers (W), T13, T18, L3 and sacrum (S) were measured before treatment, immediately after the first session, 24 h after the first session, and at 8 weeks (15 days after the last session). Linear mixed models with Tukey post hoc comparisons were used. Significant effects...
Grzegorczyk W, Soroko-Dubrovina M, Dobrowolski M, Grabska D, Dudek KD.Capacitive and resistive electric transfer (TECAR) therapy is increasingly used in equine physiotherapy; however, objective evidence regarding its immediate effects on equine back muscles remains limited. This pilot study aimed to evaluate the effects of TECAR therapy on body surface temperature and muscle tone of the longissimus dorsi muscle in Thoroughbred racehorses. A randomized, single-blinded experimental study was conducted in 20 clinically healthy Thoroughbred racehorses aged 2-3 years. Horses were randomly assigned to either a TECAR treatment group ( = 10) or a sham-treatment control ...
Su Y, Ren W, Zeng Y, Meng J, Yao X, Wang J.Skeletal muscle serves as the direct executor of movement, and the proliferation and migration capacities of its constituent cells represent the key physiological foundation determining equine endurance and speed. Previous whole-transcriptome analysis has shown that Insulin-like Growth Factor 1 () is significantly upregulated in following racing and is involved in the PI3K-Akt signaling pathway; however, its specific regulatory mechanism in equine skeletal muscle cells remains unclear. This study utilized primary equine skeletal muscle cells as a model. By constructing an overexpression plas...
Schütz D, Shield S, Patel A.Cursorial quadrupeds employ distinct mechanical strategies for high-speed locomotion, with felids relying more strongly on axial motion than equids. The biomechanical role of spinal stiffness, however, is difficult to isolate experimentally because it is coupled to limb mechanics, morphology, and coordination. Here, we used comparative three-dimensional trajectory optimization to test how spinal stiffness influences gait mechanics and actuation-demand proxies in simulated cheetah-like and horse-like galloping. Homologous cheetah and horse models were evaluated across spinal-stiffness values, p...
Kallmyr-Mack A, Hellings IR, Press CM, Ibrahim L, van Loon G, Fintl C.Myocardial sleeves (MSs) are thin layers of cardiac muscle that extend from the atria into the caval and pulmonary veins. They are recognised as important structures in both initiating and maintaining atrial tachycardia, and especially atrial fibrillation (AF), which is the most clinically important cardiac arrhythmia in horses with a reported prevalence of 1.3-2% in Standardbred racehorses. In contrast, the Norwegian-Swedish Coldblooded Trotter (NSCT) has a much lower prevalence of AF despite experiencing similar physical demands. The purpose of this study was to describe the macro-, and micr...
Harness racing performance in horses is a complex polygenic trait influenced by genetic background, breeding history, training, and environment. Understanding genomic patterns shaped by long-term artificial selection provides insights into performance-related traits and breed-specific genomic variation. Objective: This study aimed to characterize genomic differentiation, population structure, and candidate genomic regions potentially influenced by historical selection in Standardbred horses using comparative whole-genome sequencing involving diverse horse breeds. Methods: Whole-genome sequenci...
Physical exercise induces physiological adaptations associated with increased muscular activity, metabolic heat production, and changes in body surface temperature. Infrared thermography has emerged as a non-invasive technique for assessing these thermal responses in horses. The present study aimed to evaluate the ability of infrared thermography to detect changes in mean local surface temperature and to qualitatively assess alterations in thermal distribution patterns following treadmill exercise. Methods: Three clinically healthy Warmblood horses were monitored over 10 consecutive training s...
