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.
Werner LC, de Oliveira GM, Daros RR, Costa ED, Michelotto PV.The use of grimace scales enables the clinical identification of changes in the facial expressions of animals caused by pain. The Horse Grimace Scale (HGS) is one such tool, comprising a pain coding system based on facial expressions and assessing six Facial Action Units (FAUs). Each FAU is accompanied by descriptions and anatomical details to assist the evaluator. However, the morphological descriptions for certain FAUs in the HGS are not sufficiently detailed, potentially hindering accurate interpretation. This study is an analytical investigation aimed at enhancing the morphoanatomical deta...
Takahashi K, Mukai K, Ebisuda Y, Sugiyama F, Yoshida T, Hatta H, Kitaoka Y.Evidence suggests that positive pacing strategy improves exercise performance and fatigue tolerance in athletic events lasting 1-5 min. This study investigated muscle metabolic responses to positive and negative pacing strategies in Thoroughbred horses. Eight Thoroughbred horses performed 2 min treadmill running using positive (1 min at 110% maximal O uptake [V̇Omax], followed by 1 min at 90% V̇Omax) and negative (1 min at 90% V̇Omax, followed by 1 min at 110% V̇Omax) pacing strategies. The arterial-mixed venous O difference did not significantly differ between the two strategies. Pl...
Bermukhametov Z, Suleimanova K, Tomaruk O, Baimenov B, Shevchenko P, Batyrbekov A, Mikniene Z, Onur Girişgin A, Rychshanova R.A total of 396 samples were taken from the hearts, oesophagi, and diaphragms of 132 horses slaughtered at slaughterhouses in 2023 for subsequent examination. Methods: The histological method revealed pathomorphological changes in the muscle tissue. The molecular method identified the pathogen species. Results: Histological examination revealed thick-walled cysts with internal septa and numerous bradyzoites, and mononuclear inflammatory cells with pericyst infiltrates. Microcyst samples were amplified by polymerase chain reaction. Molecular genetic analysis allowed for the identification of 18 ...
Wolschrijn CF, Smit IH, Schouten J, Moller Te NCR.Facial expressions are important in pain recognition in horses, but current observation-based pain scales remain subjective. A promising technique to quantitatively measure subtle changes in expression patterns, including changes invisible to the human eye, is surface electromyography (sEMG). To achieve high-quality and reliable sEMG signals, unilateral placement of bipolar electrodes is required in relation to the motor endplates (MEP). We aimed to localize the nerve entry points (NEPs; where the nerve branch first pierced the muscle belly) and the direction of the terminal nerve endings to e...
Puccetti M, Pilati N, Beccati F, Denoix JM.To describe the clinical diagnosis, ultrasound findings, and outcome of 11 endurance horses with injuries to the serratus ventralis thoracis (SVT) or serratus ventralis cervicis (SVC) muscle. Methods: 11 endurance horses competing in medium- to high-level competitions and presenting with lameness caused by injuries to the SVT or SVC muscle, as confirmed by ultrasonography. Methods: Physical examinations revealed swelling caudal to the shoulder region associated with dorsocranial displacement of the scapula and edema of the ventral thorax for horses with SVT injuries. Swelling cranial to the sc...
Duysens J, Graide H, Niesten A, Mouithys-Mickalad A, Deby-Dupont G, Franck T, Ceusters J, Serteyn D.Muscle-derived mesenchymal stromal cells (mdMSCs) hold great promise in regenerative medicine due to their immunomodulatory properties, multipotent differentiation capacity and ease of collection. However, traditional in vitro expansion methods use fetal bovine serum (FBS) and have numerous limitations including ethical concerns, batch-to-batch variability, immunogenicity, xenogenic contamination and regulatory compliance issues. This study investigates the use of 10% equine platelet lysate (ePL) obtained by plasmapheresis as a substitute for FBS in the culture of mdMSCs in innovative 2D and 3...
Renaud B, Kruse CJ, François AC, Cesarini C, van Loon G, Palmers K, Boemer F, Luis G, Gustin P, Votion DM.Equine atypical myopathy (AM) is a severe rhabdomyolysis syndrome primarily caused by hypoglycin A (HGA) and methylenecyclopropylglycine protoxins. This study aimed to refine diagnostic and prognostic criteria for AM while exploring apparently healthy cograzers. Blood samples from 263 horses, including AM cases (n= 95), cograzers (n= 73), colic horses (n= 19), and controls (n= 76), were analyzed for HGA, its toxic metabolite, and acylcarnitines profile. Diseased horses exhibited alterations in acylcarnitines that strongly distinguished them from controls and colic horses. Regression analyses i...
Ding W, Gong W, Liu H, Hu H, Shi L, Ren X, Cao Y, Zhang A, Shi X, Li Z, Bou T, Dugarjaviin M, Bai D.The growth and development of myofibers, as the fundamental units comprising muscle tissue, and their composition type are indeed among the most crucial factors influencing skeletal muscle types. Muscle fiber adaptation is closely associated with alterations in physiological conditions. Muscle fiber types undergo dynamic changes in fetus and adult horses. Our aim is to investigate the mechanisms influencing the differences in muscle fiber types between fetal and adult stages of Mongolian horses. The study investigated the distribution of muscle fiber types within longissimus dorsi muscle of fe...
van Bijlert PA, Geijtenbeek T, Smit IH, Schulp AS, Bates KT.Musculoskeletal simulations can provide insights into the underlying mechanisms that govern animal locomotion. In this study, we describe the development of a new musculoskeletal model of the horse, and to our knowledge present the first fully muscle-driven, predictive simulations of equine locomotion. Our goal was to simulate a model that captures only the gross musculoskeletal structure of a horse, without specialized morphological features. We mostly present simulations acquired using feedforward control, without state feedback ("top-down control"). Without using kinematics or motion captur...
Lindsay-McGee V, Massey C, Li YT, Clark EL, Psifidi A, Piercy RJ.Equine exercise-associated myopathies are prevalent, clinically heterogeneous, generally idiopathic disorders characterised by episodes of myofibre damage that occur in association with exercise. Episodes are intermittent and vary within and between affected horses and across breeds. The aetiopathogenesis is often unclear; there might be multiple causes. Poor phenotypic characterisation hinders genetic and other disease analyses. Objective: The aim of this study was to characterise phenotypic patterns across exercise-associated myopathies in horses. Methods: Historical cross-sectional study, w...
Graham-Thiers P, Bowen K.Eight geldings weighing 544 ± 16 kg were used to evaluate feeding a postexercise protein meal on plasma amino acids during recovery. Horses were fed sweet feed, corn, grass hay and equal amounts of a protein pellet (32% CP) with meals (MP group) or postexercise (EP group). Horses exercised 1-2 h/day, 5 days/week, for 12 weeks. A pre and poststudy 4 days total urine and feces collection was conducted. Urine and fecal samples were analyzed for nitrogen (N) to calculate N balance. Blood samples were drawn immediately after and at 1 and 3 h postexercise at the start and end of the stud...
Stellmack JM, Logan AA, Higgins AH, Hoffman RM.Periods of limited activity during semester break may reduce performance during return to ridden work. This study evaluated fitness and muscling of horses when returning to work, following a 12-week period during which horses either continued (conditioned) or discontinued (non-conditioned) ridden work. It was hypothesized that non-conditioned horses would have a lower level of fitness, resulting in higher resting and peak heart rates and lower levels of muscling. Twelve mature, stock type horses aged 16 ± 5 years were assigned to either a conditioned group that maintained light-to-moderate ri...
Baudisch N, Singer E, Jensen KC, Eichler F, Meyer HJ, Lischer C, Ehrle A.Surgical treatment options for horses with overriding dorsal spinous processes include interspinous ligament desmotomy and partial spinous process ostectomy. The impact of spinal surgery on the three-dimensional biomechanics of the equine thoracolumbar spine and the epaxial musculature is unclear. Objective: To investigate the influence of interspinous ligament desmotomy and cranial wedge ostectomy on the biomechanics of the equine thoracolumbar spine and the paraspinal Musculi multifidi. Methods: Ex-vivo experiments. Methods: Twelve equine thoracolumbar spine specimens were mounted in a custo...
Wang J, Ren W, Sun Z, Han Z, Zeng Y, Meng J, Yao X.This study conducted a thorough analysis of the myofiber type composition in the extensor digitorum longus muscle (EDL) and soleus muscle (SOL) of Kazakh horses, across different genders (male and female). The results showed significant differences in myofiber type composition between EDL and SOL, with a higher proportion of Type I fibers in SOL muscles and a greater prevalence of Type II fibers in EDL muscles. Additionally, the myofiber diameter in Kazakh horses was relatively small, potentially related to the tenderness and edible quality of their muscles. Using high-throughput sequencing te...
Fresa K, Catandi GD, Whitcomb L, Gonzalez-Castro RA, Chicco AJ, Carnevale EM.Obesity is a complex disease associated with augmented risk of metabolic disorder development and cellular dysfunction in various species. The goal of the present study was to investigate the impacts of obesity on the metabolic health of old mares as well as test the ability of diet supplementation with either a complex blend of nutrients designed to improve equine metabolism and gastrointestinal health or L-carnitine alone to mitigate negative effects of obesity. Mares (n = 19, 17.9 ± 3.7 years) were placed into one of three group: normal-weight (NW, n = 6), obese (OB, n = 7...
Takahashi Y, Takahashi T, Mukai K, Ebisuda Y, Ohmura H.Understanding how muscle activity changes with different surface grades during canter is essential for developing training protocols in Thoroughbreds because canter is their primary gait in training and races. We measured the spatiotemporal parameters and the activation of 12 surface muscles in the leading limb side of 7 Thoroughbreds. Horses were equipped with hoof strain gauges and cantered at 10 m/s on a treadmill set to grades of -4%, 0%, 4%, and 8%, randomly, for 30 seconds each without a lead change. Integrated electromyography (iEMG) values during stance and swing phases were calculated...
Aleman M.Inflammatory myopathies or myositis encompass diseases characterized by the presence of inflammatory cellular infiltrates, mainly polymorphonuclear cells and/or lymphocytes, in muscle. This is in contrast to most forms of muscle disease characterized by myodegeneration that results in macrophage infiltration. Inflammatory myopathies could have infectious or noninfectious causes. Noninfectious causes consist of primary (genetic, autoimmune) or acquired immune-mediated disease. Focal, multifocal or diffuse, acute or recurrent forms of disease can occur. This article will mainly review immune-med...
Dyson S, Zheng S, Aleman M.Detailed descriptions of clinical signs associated with radiological findings of the caudal cervical vertebral column are not available. Objective: Describe the clinical features associated with neck pain or stiffness, neck-related thoracic limb lameness, proprioceptive ataxia consistent with a cervicothoracic spinal cord or nerve lesion, and their frequency of occurrence compared with control horses. Methods: A total of 223 Warmblood horses. Methods: Case-control study. Controls and cases were recruited prospectively. All horses underwent predetermined lameness and neurologic examinations. Th...
Ramos GV, Santos MM, Gava FN, de Lacerda-Neto JC.The effects of conditioning on cardiac function in young horses is still unknown. For this reason, this study evaluated the left ventricular (LV) function of young horses by echocardiography after six weeks of conditioning. Fourteen untrained young purebred Arabian horses were evaluated at rest and after a stress test (ST) before and after a six-week conditioning program. There was an increase in V4 (p < 0.001) after conditioning, as well as a reduction in both heart rate (HR) at rest and peak HR during the ST (p < 0.001). There was also a reduction in internal diameter, along with an in...
Ebisuda Y, Mukai K, Takahashi Y, Yoshida T, Matsuhashi T, Kawano A, Miyata H, Kuwahara M, Ohmura H.This study aimed to determine whether heat acclimation could induce adaptations in exercise performance, thermoregulation, and the expression of proteins associated with heat stress in the skeletal muscles of Thoroughbreds. Thirteen trained Thoroughbreds performed 3 weeks of training protocols, consisting of cantering at 90% maximal oxygen consumption (VO2max) for 2 min 2 days/week and cantering at 7 m/s for 3 min 1 day/week, followed by a 20-min walk in either a control group (CON; Wet Bulb Globe Temperature [WBGT] 12-13°C; n = 6) or a heat acclimation group (HA; WBGT 29-30°...
Argüelles D, Saitua A, Miraz R, Calle-González N, Requena F, Nocera I, Vitale V, Sgorbini M, Muñoz A.It has been reported that capacitive resistive electric transfer (CRET) increases blood circulation, hemoglobin oxygenation and temperature in muscles. The attributed benefits of these changes have been linked to improved athletic performance, enhanced muscle flexibility and fastening recovery from exercise-induced fatigue. For all of this, the present research aims to investigate whether the application of CRET 24 h before exercise affects the accelerometric pattern in horses during exercise. Six sound Standardbred trotters were subjected to a CRET session of 40 min of duration, applied on ...
Oliveira BE, Canola PA.Ultrasonographic imaging of the diaphragm is a non-invasive alternative for respiratory function evaluation in horses. This study aimed to measure diaphragm thickness, thickening (change in thickness with contraction) and thickening fraction in healthy adult horses during tidal breathing and forced vital capacity. Correlation between body weight (≤400 kg and >400 kg) and diaphragm thickness was investigated. To that purpose, 20 adult horses, weight 409±50 kg, height 1.47±0.05 m, and age 16±6 years were included in the study. Diaphragm thickness was measured at end-inspiration and end-e...
Reis IL, Lopes B, Sousa P, Sousa AC, Caseiro AR, Mendonça CM, Santos JM, Atayde LM, Alvites RD, Maurício AC.Musculoskeletal injuries such as equine osteoarthritis, osteoarticular defects, tendonitis/desmitis, and muscular disorders are prevalent among sport horses, with a fair prognosis for returning to exercise or previous performance levels. The field of equine medicine has witnessed rapid and fruitful development, resulting in a diverse range of therapeutic options for musculoskeletal problems. Staying abreast of these advancements can be challenging, prompting the need for a comprehensive review of commonly used and recent treatments. The aim is to compile current therapeutic options for managin...
Ren W, Wang J, Zeng Y, Wang T, Sun Z, Meng J, Yao X.This study conducted transcriptome sequencing on the skeletal muscles of three different anatomical locations across various growth stages to investigate the impact of ages on crucial candidate genes and molecular mechanisms associated with muscle development in Kazakh horses. Sixteen Kazakh horses were selected, and they were divided into four age groups, each with four biological replicates. Tissue samples from the longest dorsal muscle, abdominal muscle, and diaphragm muscle were collected for analysis. The results revealed differential mRNA expression in the longest dorsal muscle between t...
Artman JL, Wesolowski LT, Semanchik PL, Isles JK, Norton SA, White-Springer SH.We aimed to test the hypothesis that repeated muscle collections would impact mitochondrial function, antioxidant status, and markers of inflammation and muscle damage. Twenty-six horses (8 geldings, 18 mares; mean±SD 9.5±3.5 y) had gluteus medius muscle biopsy samples collected at: 0 and 24h (n=7); 0 and 6h (n=6); 0, 6, and 12h (n=7); or 0, 6, 12, and 24h (n=6). Blood was collected from all horses every 6h for 72h, starting 24h prior to the 0h muscle collection. Data were analyzed using mixed linear models. Muscle integrative (per mg tissue) electron transfer capacity of complex II decrease...
Zhang X, Geng A, Cao D, Dugarjaviin M. Horses are susceptible to oxidative stress during strenuous endurance exercise, leading to muscle fatigue and damage. Mulberry leaf flavonoids (MLFs) possess significant antioxidant properties. However, the antioxidant efficacy of MLFs can be influenced by the extraction process, and their impact on HO-induced oxidative stress in equine skeletal muscle satellite cells (ESMCs) remains unexplored. Our study employed three extraction methods to obtain MLFs: ultrasound-assisted extraction (CEP), purification with AB-8 macroporous resin (RP), and n-butanol extraction (NB-EP). We assessed the prot...
Romero Corrêa R, Peres Mendes R, Darley Velasquez Piñeros D, De Lima AE, do Valle De Zoppa AL, Lopes Correia da Silva LC, de Francisco Strefezzi R....Preservation of biological tissues has been used since ancient times. Regardless of the method employed, tissue preservation is thought to be a vital step in veterinary surgery teaching and learning. Objective: This study was designed to determine the usability of chemically preserved cadaveric equine heads for surgical teaching in veterinary medicine. Methods: Six cadaveric equine heads were collected immediately after death or euthanasia and frozen until fixation. Fixation was achieved by using a hypertonic solution consisting of sodium chloride, sodium nitrite and sodium nitrate, and an alc...
St George LB, Spoormakers TJP, Hobbs SJ, Clayton HM, Roy SH, Richards J, Serra Bragança FM.Despite its proven research applications, it remains unknown whether surface electromyography (sEMG) can be used clinically to discriminate non-lame from lame conditions in horses. This study compared the classification performance of sEMG absolute value (sEMGabs) and asymmetry (sEMGasym) parameters, alongside validated kinematic upper-body asymmetry parameters, for distinguishing non-lame from induced fore- (iFL) and hindlimb (iHL) lameness. Bilateral sEMG and 3D-kinematic data were collected from clinically non-lame horses ( = 8) during in-hand trot. iFL and iHL (2-3/5 AAEP) were induced...
Duysens J, Graide H, Niesten A, Mouithys-Mickalad A, Ceusters J, Serteyn D.The main causes of mortality in horses are the gastrointestinal pathologies associated with septic shock. Stem cells have shown, through systemic injection, a capacity to decrease inflammation and to regenerate injured tissue faster. Nevertheless, to achieve this rapid and total regeneration, systemic injections of 1 to 2 million cells per kilogram of body weight must be considered. Here, we demonstrate for the first time the feasibility and expansion capacity of equine muscle-derived mesenchymal stromal cells (mdMSCs) in a functionally closed, automated, perfusion-based, hollow-fiber bioreact...
Stewart AA, Barrett JG, Byron CR, Yates AC, Durgam SS, Evans RB, Stewart MC.To compare viability and biosynthetic capacities of cells isolated from equine tendon, muscle, and bone marrow grown on autogenous tendon matrix. Methods: Cells from 4 young adult horses. Methods: Cells were isolated, expanded, and cultured on autogenous cell-free tendon matrix for 7 days. Samples were analyzed for cell viability, proteoglycan synthesis, collagen synthesis, and mRNA expression of collagen type I, collagen type III, and cartilage oligomeric matrix protein (COMP). Results: Tendon- and muscle-derived cells required less time to reach confluence (approx 2 weeks) than did bone marr...
Debuse D, Gibb C, Chandler C.Although there is now some evidence for specific effects of hippotherapy on people with cerebral palsy, these studies fail to provide a comprehensive picture of the effects of hippotherapy. This was the first qualitative study to explore the hippotherapy experience of people with cerebral palsy from a user perspective. The effects of hippotherapy and their context were of particular interest. Seventeen users aged from 4 to 63, with or without their parents, participated in focus groups or individual interviews in six centres in Britain and in Germany. The main effects of hippotherapy, as ident...
Kearns CF, McKeever KH, Kumagai K, Abe T.This study examined whether body composition was predictive of competitive success in elite standardbreds (STB). Rump fat and muscle thickness (MTH) (vastus lateralis/intermedius [VL], extensor carpi radialis [ECR]) were measured in vivo in male n=6; female n=8 by B-mode ultrasound. Percentage body fat (%fat) was calculated from rump fat. There were no gender differences for age, body mass (males 432+/-11 kg; females 443+/-13 kg), fat-free mass (FFM) (males 400+/-12 kg; females 400+/-11 kg), ECR MTH (males 61+/-2 cm; females 60+/-2 cm) or race time (RT) (males 113+/-3 s; females 114+/-2 s). Ma...
Bao T, Han H, Li B, Zhao Y, Bou G, Zhang X, Du M, Zhao R, Mongke T, Laxima , Ding W, Jia Z, Dugarjaviin M, Bai D.Skeletal muscle is the largest organ system in the mammalian body and plays a key role in locomotion of horses. Fast and slow muscle fibers have different abilities and functions to adapt to exercises. To investigate the RNA and miRNA expression profiles in the muscles with different muscle fiber compositions on Mongolian horses. We examined the muscle fiber type population and produced deep RNA sequencing for different parts of skeletal muscles. And chose two of them with the highest difference in fast and slow muscle fiber population (splenius and gluteus medius) for comparing the gene expre...
Hilliere C, Collado-Mateo D, Villafaina S, Duque-Fonseca P, Parraça JA.To provide an up-to-date research analysis on equine-assisted therapies and horse riding simulation exercise in older adults, and to suggest future directions in clinical practice and research. TYPE: Systematic review. A comprehensive search of studies was performed in 4 electronic databases (Cochrane, PubMed, PEDro, and Web of Science) regarding the effects of equine-assisted therapies and horse riding simulation exercise in older adults. Eight articles were selected, 5 of them focused on hippotherapy, 2 on horse riding simulation, and a single article that used the 2 types of therapy. PRISMA...
Essén-Gustavsson B, Lindholm A.Muscle biopsies were taken from the middle gluteus muscle of 36 Standardbred horses. Twelve of the horses were inactive, while 24 were actively trained and raced. Twelve of the trained horses were moderate performers, with a mean racing time of 1 min 21 secs per km (741 m/min) and the other 12 were excellent performers, with a mean racing time of 1 min 16 secs per km (789 m/min). The percentage and mean area of Type I fibres were similar in all three groups of horses. Marked differences were found among the subgroups of Type II fibres. The well-trained horses had a higher proportion of Type II...
McCutcheon LJ, Byrd SK, Hodgson DR.Thoroughbred horses were exercised to fatigue at 40, 85, and 100% of their maximal oxygen consumption (VO2max) on a treadmill and completed a 1,600-m gallop on a track to identify the effect of exercise of various durations and intensities on the ultrastructure of mitochondria and sarcoplasmic reticulum (SR) from the middle gluteal muscle. The percentage of the total area occupied by mitochondria and SR increased in electron micrographs of muscle samples collected at the termination of exercise and at 30 and 60 min of recovery compared with those collected before exercise. Mitochondrial area i...
Payne RC, Veenman P, Wilson AM.Muscles have two major roles in locomotion: to generate force and to absorb/generate power (do work). Economical force generation is achieved by short-fibred pennate muscle while the maximum power output of a muscle is architecture independent. In this study we tested the hypothesis that there is an anatomical and structural separation between the force-generating anti-gravity muscles and the propulsive (limb/trunk moving) muscles of the equine forelimb. Muscle mass and fascicle length measurements were made on the thoracic limb extrinsic muscles of six fresh horse cadavers. Physiological cros...
Finno CJ, Valberg SJ, Wünschmann A, Murphy MJ.To determine clinical signs, diagnostic findings, tissue tremetone concentrations, and clinical outcome or postmortem findings in horses evaluated for acute severe nonexertional rhabdomyolysis initially attributed to white snakeroot toxicosis. Methods: Retrospective case series. Methods: 14 horses. Methods: Records of the University of Minnesota Veterinary Medical Center or Diagnostic Laboratory were searched from 1998 to 2005. Inclusion criteria included serum creatine kinase (CK) activity > 45,000 U/L, severe nonexertional myonecrosis of proximal postural muscles at necropsy, or signs of wea...
Guy PS, Snow DH.1. Percutaneous needle biopsies were obtained from six limb muscles in six horses before and during a training programme of 10 or 15 weeks designed to involve both aerobic and anaerobic work. In a subsequent detraining period, biopsies were also taken after 5 and 10 weeks. 2. Samples were analysed biochemically for enzyme activity of lactic dehydrogenase (LDH), creatine phosphokinase (CPK), aldolase (ALD), citrate synthase (CS), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) and for glycogen content. Fibre typing was carried out histochemically before and 10 weeks after c...
Prieto D, Simonsen U, Hernández M, García-Sacristán A.1. Penile small arteries (effective internal lumen diameter of 300 600 microm) were isolated from the horse corpus cavernosum and mounted in microvascular myographs in order to investigate the mechanisms underlying the endothelium-dependent relaxations to acetylcholine (ACh) and bradykinin (BK). 2. In arteries preconstricted with the thromboxane analogue U46619 (3-30 nM), ACh and BK elicited concentration-dependent relaxations, pD2 and maximal responses being 7.71+/-0.09 and 91+/-1 % (n=23), and 8.80+/-0.07 and 89+/-2% (n=24) for ACh and BK, respectively. These relaxations were abolished by me...
Quattrocelli M, Giacomazzi G, Broeckx SY, Ceelen L, Bolca S, Spaas JH, Sampaolesi M.Induced pluripotent stem cells (iPSCs) hold great potential not only for human but also for veterinary purposes. The equine industry must often deal with health issues concerning muscle and cartilage, where comprehensive regenerative strategies are still missing. In this regard, a still open question is whether equine iPSCs differentiate toward muscle and cartilage, and whether donor cell type influences their differentiation potential. We addressed these questions through an isogenic system of equine iPSCs obtained from myogenic mesoangioblasts (MAB-iPSCs) and chondrogenic mesenchymal stem ce...
Matusovsky OS, Kachmar L, Ijpma G, Bates G, Zitouni N, Benedetti A, Lavoie JP, Lauzon AM.Heaves is a naturally occurring equine disease that shares many similarities with human asthma, including reversible antigen-induced bronchoconstriction, airway inflammation, and remodeling. The purpose of this study was to determine whether the trachealis muscle is mechanically representative of the peripheral airway smooth muscle (ASM) in an equine model of asthma. Tracheal and peripheral ASM of heaves-affected horses under exacerbation, or under clinical remission of the disease, and control horses were dissected and freed of epithelium to measure unloaded shortening velocity (Vmax), stress...
Aranda-García S, Iricibar A, Planas A, Prat-Subiran JA, Angulo-Barroso RM.This study evaluates the separate effect and retention of 12-week traditional (TE) and horse (HE) exercise programs on physical function in healthy older participants (61 to 87 years old). Thirty-eight participants were randomly assigned to three groups: TE (n = 17), HE (n = 10), and control group (n = 11). TE and HE underwent a supervised exercise program (3 day/week). Maximal gait speed, muscle strength, and body balance were assessed at weeks 0, 12, and 16. Only TE and HE displayed significant improvements (P < .05) in knee extensor strength, and only HE had faster gait speed. Marginal b...
Grandy JL, Steffey EP, Hodgson DS, Woliner MJ.The effect of halothane-induced hypotension on the development of postanesthetic myopathy was studied, using 6 healthy adult horses. Horses were anesthetized with halothane in oxygen for 3.5 hours on each of 2 occasions. Intermittent positive-pressure ventilation was used to maintain PaCO2 of 45 to 55 mm of Hg throughout both anesthetic exposures. By regulating the inspired halothane concentration, a mean arterial blood pressure of 85 to 95 mm of Hg (normotension) was maintained throughout the 1st anesthetic exposure, and a mean arterial blood pressure of 55 to 65 mm of Hg (hypotension) was ma...
St George L, Clayton HM, Sinclair J, Richards J, Roy SH, Hobbs SJ.Selection and training practices for jumping horses have not yet been validated using objective performance analyses. This study aimed to quantify the differences and relationships between movement and muscle activation strategies in horses with varying jump technique to identify objective jumping performance indicators. Surface electromyography (sEMG) and three-dimensional kinematic data were collected from horses executing a submaximal jump. Kinematic variables were calculated based on equestrian-derived performance indicators relating to impulsion, engagement and joint articulation. Horses ...
Valberg SJ, Cardinet GH, Carlson GP, DiMauro S.A polysaccharide storage myopathy is described in nine Quarterhorses, Quarterhorse crossbreds, American Paints and Appaloosa horses which had a history of recurrent exertional rhabdomyolysis. Muscle biopsies were characterized by high muscle glycogen concentrations with up to 5% of type 2 muscle fibers containing inclusions which stained positively with the periodic acid Schiff (PAS) stain. The inclusions were classified as an acid mucopolysaccharide, based on their histochemical staining characteristics. Ultrastructural studies revealed that the inclusions were composed of beta glycogen parti...
Siger L, Bowen R, Karaca K, Murray M, Jagannatha S, Echols B, Nordgren R, Minke JM.Efficacy of the Recombitek Equine West Nile Virus (WNV) vaccine was evaluated against a WNV intrathecal challenge model that results in WNV-induced clinical disease. Ten vaccinated (twice at days 0 and 35) and 10 control horses were challenged 2 weeks after administration of the second vaccine with a virulent WNV by intrathecal administration. After the challenge, eight of 10 controls developed clinical signs of encephalomyelitis whereas one vaccinate exhibited muscle fasciculation only once. Nine controls and one vaccinate developed a fever. Histopathology revealed mild to moderate nonsuppura...
Beldarrain LR, Morán L, Sentandreu MÁ, Insausti K, R Barron LJ, Aldai N.A full-randomized block design was used for the study of the FA composition and meat quality parameters, considering ageing time as a split-plot factor. Chemical and fatty acid composition of steaks (longissimus thoracis and lumborum muscle) from 15 month old semiextensively reared Hispano-Bretón horses were characterized (day 0), and the effect of vacuum ageing (0, 7, 14 and 21 days) on several meat quality parameters (pH, instrumental color and texture and cook loss) was determined. The average fat content of horse loin was 3.31%, and the n-3 polyunsaturated fatty acid content, although hig...
Yarnell K, Fleming J, Stratton TD, Brassington R.Infrared thermography (IRT) was used to assess surface temperature change as an indirect measure of muscle activity and exercise associated changes in blood flow in the working hind limb muscles of horses (n=7) undergoing water treadmill exercise. Three treatments were investigated including the treadmill ran dry (TD), water at the height of the proximal interphalangeal joint (PIP) and water at the height of the carpus (CP). Maximum skin surface temperature was recorded from the region of the semitendinosus muscle during exercise at each water height. There was a significant difference in surf...
Finno CJ, Gianino G, Perumbakkam S, Williams ZJ, Bordbari MH, Gardner KL, Burns E, Peng S, Durward-Akhurst SA, Valberg SJ.The cause of immune-mediated myositis (IMM), characterized by recurrent, rapid-onset muscle atrophy in Quarter Horses (QH), is unknown. The histopathologic hallmark of IMM is lymphocytic infiltration of myofibers. The purpose of this study was to identify putative functional variants associated with equine IMM. A genome-wide association (GWA) study was performed on 36 IMM QHs and 54 breed matched unaffected QHs from the same environment using the Equine SNP50 and SNP70 genotyping arrays. A mixed model analysis identified nine SNPs within a ~ 2.87 Mb region on chr11 that were significantly (...
Rivero JL, Talmadge RJ, Edgerton VR.The aim of this study was to characterize the myosin heavy chain (MyHC) isoforms present in equine skeletal muscle. Methods: Muscle biopsies were removed from the superficial region of the gluteus medius muscle of five mature horses and analyzed by immunohistochemistry (using a battery of monoclonal antibodies specific for rat MyHC isoforms) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Results: Immunohistochemistry allowed subdivision of three different muscle fiber populations containing a single MyHC, one slow and two fast, and two hybrid populations, one containing slow an...
White SH, Johnson SE, Bobel JM, Warren LK.Untrained Thoroughbred horses (6 mares and 6 geldings; 11 yr [SE 1] and 565 kg [SE 11]) were used to evaluate antioxidant gene expression and enzyme activity in blood and skeletal muscle in response to prolonged exercise after receiving 2 levels of dietary selenium for 36 d: 0.1 (CON; = 6) or 0.3 mg/kg DM (SEL; = 6). Horses were individually fed 1.6% BW coastal bermudagrass hay, 0.4% BW whole oats, and a mineral/vitamin premix containing no Se. Sodium selenite was added to achieve either 0.1 or 0.3 mg Se/kg DM in the total diet. On d 35, horses underwent 2 h of submaximal exercise in a free-st...
Scheidegger MD, Gerber V, Dolf G, Burger D, Flammer SA, Ramseyer A.Early recognition of lameness is crucial for injury prevention. Quantitative gait analysis systems can detect low-grade asymmetries better than the human eye and may be useful in early lameness recognition. The aims of this study were (1) to investigate the frequency of gait asymmetries based on head and pelvic movement in elite eventing horses using inertial mounted measurement units and (2) to assess the association between asymmetries and muscle enzymes and blood lactate (LA) levelspost-exercise. Movement asymmetry of the head, wither, and pelvis were quantified in 33 elite eventing horses ...
White SH, Warren LK.Exercise is associated with increased production of reactive oxygen species (ROS) as metabolism is upregulated to fuel muscle activity. If antioxidant systems become overwhelmed, ROS can negatively affect health and performance. Adaptation to exercise through regular training has been shown to improve defense against oxidative insult. Given selenium's role as an antioxidant, we hypothesized that increased Se intake would further enhance skeletal muscle adaptations to training. Quarter Horse yearlings (18 ± 0.2 mo; 402 ± 10 kg) were randomly assigned to receive either 0.1 or 0.3 mg Se/kg DM a...
Valberg S, Jönsson L, Lindholm A, Holmgren N.Six horses with a history of recurrent exertional rhabdomyolysis (RER) (Horses A-F) and 7 control horses performed a submaximal and later a near-maximal treadmill exercise test. Blood samples were obtained before, during and after exercise and muscle biopsies were taken before and after exercise. At rest, plasma aspartate aminotransferase (AST) activities in horses with RER were above 95% confidence intervals for control horses. During submaximal exercise, 3 horses with RER (A, B and C) had much greater increases in plasma AST, creatine kinase (CK) and myoglobin concentrations than did Horses ...
Spier SJ, Carlson GP, Holliday TA, Cardinet GH, Pickar JG.Eleven horses (3 mares, 7 stallions, 1 gelding) with clinical and biochemical evidence of hyperkalemic periodic paralysis were studied. Each horse had history of episodic weakness, muscular tremors, or collapse, which lasted for periods of a few minutes to hours. Diagnosis was based on hyperkalemia in association with a spontaneous episode of paralysis or by precipitation of an episode by oral administration of potassium chloride. Clinical and biochemical events were documented during spontaneous and induced episodes of muscular weakness. During episodes, electrocardiographic findings were con...
Crook TC, Cruickshank SE, McGowan CM, Stubbs N, Wakeling JM, Wilson AM, Payne RC.The Quarter Horse (bred for acceleration) and the Arab (bred for endurance) are situated at either end of the equine athletic spectrum. Studies into the form and function of the leg muscles in human sprint and endurance runners have demonstrated that differences exist in their muscle architecture. It is not known whether similar differences exist in the horse. Six Quarter Horse and six Arab fresh hind limb cadavers were dissected to gain information on the muscle mass and architecture of the following muscles: gluteus medius; biceps femoris; semitendinosus; vastus lateralis; gastrocnemius; tib...
Lui TH.Flexor hallucis longus muscle can adhere to the distal tibia after tibial fracture. The patient may complain of deep posteromedial ankle pain, checkrein deformity of the hallux, hallux flexus or development of hallux rigidus. Surgical treatment of release of the FHL muscle or lengthening of the FHL tendon has been proposed. We described an endoscopic approach of release of the FHL muscle from the distal tibia with the advantage of minimal soft tissue dissection. Methods: Therapeutic Level V: Expert Opinion/Technique.
Foster CV, Harris RC.To study the changes in carnitine in muscle with spring exercise, two Thoroughbred horses performed two treadmill exercise tests. Biopsies of the middle gluteal were taken before, after exercise and after 12 min recovery. Resting mean muscle total carnitine content was 29.5 mmol.kg-1 dry muscle (d.m.). Approximately 88% was free carnitine, 7% acetylcarnitine and acylcarnitine was estimated at 5%. Exercise did not affect total carnitine, but resulted in a marked fall in free carnitine and almost equivalent rise in acetylcarnitine. The results are consistent with a role for carnitine in the regu...
