The musculoskeletal system in horses encompasses the bones, muscles, tendons, ligaments, and joints that facilitate movement and provide structural support. This system is essential for locomotion, athletic performance, and overall health in equine species. The equine skeleton consists of approximately 205 bones, which are connected by joints and supported by a network of muscles and connective tissues. Tendons connect muscles to bones, while ligaments link bones to other bones, contributing to joint stability. The musculoskeletal system is subject to various conditions, including injuries, degenerative diseases, and developmental disorders, which can impact a horse's mobility and performance. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, physiology, pathology, and treatment of musculoskeletal conditions in horses.
Breen LJ, Stack JD, Gillen AM, Baldwin CM.(1) To evaluate the feasibility of needle tenoscopy of the digital flexor tendon sheath (DFTS) using basisesamoid (BS) and proximolateral (PL) approaches in a standing equine cadaver model. (2) To report visualization of intrathecal DFTS anatomy via both approaches. (3) To determine the efficacy of needle scope-guided palmar/plantar annular ligament (PAL) desmotomy. (4) To report any iatrogenic damage associated with the procedure. Methods: Ex vivo experimental. Methods: Ten equine cadaver limbs. Methods: Limbs were placed in a Kimzey leg-saver splint and needle tenoscopy was performed using t...
Orozco Lopez D, Garcia-Lopez JM, Carpenter R, Bras JJ, Richardson DW, Ortved KF.To describe the outcome of metacarpophalangeal (MCPJ) and proximal interphalangeal joint (PIPJ) arthrodesis using a locking compression-distal femur plate (LCP-DFP) in Thoroughbred racehorses with traumatic disruption of the suspensory apparatus (TDSA) at risk of PIPJ subluxation. Methods: Multicenter retrospective study. Methods: Twenty-six Thoroughbred racehorses. Methods: Records of Thoroughbred racehorses with TDSA that had undergone MCPJ and PIPJ arthrodesis using an LCP-DFP at three referral hospitals between 2020 and 2024 were reviewed for inclusion. The preoperative data collected incl...
Harbowy RM, Nielsen BD, Colbath AC, Robison CI, Buskirk DD, Logan AA.Though circular exercise is commonly used in equestrian disciplines, it may be at the detriment of horses' musculoskeletal system. To investigate the effects of circular exercise on bone and joint health, 42 lambs were randomly assigned to a non-exercised control, straight-line, small circle, or large circle exercise regime at a slow (1.3 m/s) or fast (2.0 m/s) speed for 12 wk. Blood samples were taken biweekly. Animals were humanely euthanized upon study completion, and the fused third and fourth metacarpals were collected for biomechanical testing and bone density analysis. Fast groups were ...
Colla S, Johnson JW, McGilvray KC, Zanotto GM, Seabaugh KA.Therapeutic shoeing for horses is used to affect the palmar angle (PA) of the distal phalanx. These changes may influence the strain on the distal interphalangeal joint collateral ligaments (DIJCLs). This cadaveric study aimed to assess DIJCL strain under varying loads and PA adjustments. Using 26 cadaver forelimbs, eight optical markers were placed on one DIJCL for strain measurement under five different loads (1000-5000 newtons) at a neutral PA, followed by PA increases of 2°, 4°, and 6° and decreases of -2° and -4°. The results indicate that increases in PA corresponded to significantl...
Valberg SJ.Although horses most commonly develop exertional rhabdomyolysis, there are numerous causes for nonexertional rhabdomyolysis (nonER) that pose a serious health threat to horses. Their etiologies can be broadly categorized as toxic, genetic, inflammatory/infectious, nutritional, and traumatic and a variety of diagnostic tests are available to discern among them. This study discusses causes of nonER as well as diagnostics and treatments that are specific to each etiology. General treatment of acute rhabdomyolysis is covered in detail in the study in this issue on sporadic and recurrent exertional...
King MR, Colla S.Successful rehabilitation of muscle injury requires a comprehensive understanding of the injury process, healing phases, and resources to be employed. The initial phase is characterized by acute inflammatory signs, followed by the regenerative and remodeling phases. Therapeutic exercises can be utilized in all 3 phases, progressing from isometric exercises to aquatic therapies. The classification and phase of injury and the individual response to the applied therapies will guide the progression of the therapeutic exercises through the rehabilitation program.
Finno CJ, McKenzie E.Nutritional deficiencies of vitamin E and selenium can occur alone or concurrently. Prolonged and sustained deficiency of either or both nutrients can lead to profound clinical disease. Selenium deficiency can also result in signs of cardiac disease, upper gastrointestinal dysfunction, and abortion or the birth of weak foals. Deficiencies can usually be readily established by evaluating the dietary intake of individuals and by measurement of blood concentrations of these nutrients. Treatment of clinical disease is not always successful and prolonged morbidity and mortality can be encountered; ...
McKenzie E.The equine muscle system is complex and prone to a large range of hereditary and acquired diseases that often have overlapping clinical signs with orthopedic, neurologic, and other disorders. Obtaining a clinical history that fully outlines the client concerns and any known information about the disorder and following with a comprehensive physical examination and screening clinical pathology tests are fundamental to achieve definitive diagnosis. A methodical and comprehensive approach aids accurate diagnosis and development of an optimal treatment and management plan. This article describes th...
McGowan C.Traumatic muscle injuries are likely to be frequent in athletic horses yet are often overlooked. These injuries usually involve internal (intrinsic) trauma, and particularly occur in athletic horses exercising at higher intensities, at unaccustomed workloads, or performing work requiring sudden acceleration, deceleration, and/or direction changes. These injuries can present with signs ranging from acute pain and lameness in a localized region to unexplained elevations of muscle enzymes on routine blood tests with or without poor performance. They include exercise-induced muscle damage such as ...
Finno CJ.In the field of equine muscle disorders, many conditions have a genetic basis. Therefore, genetic testing is an important part of the diagnostic evaluation. Validated genetic tests are currently available for 5 equine muscle disorders: hyperkalemic periodic paralysis, malignant hyperthermia, glycogen branching enzyme disease, type 1 polysaccharide storage myopathy, and myosin heavy chain myopathy. These diseases should be tested for in the appropriate breeds with clinical signs of disease or as part of breeding management. Genetic testing in veterinary medicine is not regulated, and therefore,...
Durward-Akhurst SA, Valberg SJ.Several inflammatory myopathies have an infectious or immune-mediated basis in the horse. Myosin heavy chain myopathy is caused by a codominant missense variant in MYH1 and has 3 clinical presentations: immune-mediated myositis, calciphylaxis, and nonexertional rhabdomyolysis in Quarter Horse-related breeds. An infarctive form of purpura hemorrhagica affects numerous breeds, presenting with focal firm, painful muscle swelling, and subsequent infarction of multiple tissues. While Streptococcus equi equi is often the inciting cause, anaplasmosis, sarcocystis, piroplasmosis, viruses, and vaccines...
Aleman M.Muscle disease has various clinical manifestations that range from exertional and non-exertional rhabdomyolysis, fasciculations, weakness, rigidity, stiffness, gait abnormalities, poor performance, and alterations in muscle mass and tone. Neurogenic disorders and non-neurogenic disorders such as primary muscle disease can cause muscle atrophy and changes in muscle tone. Myotonic disorders can have a genetic (eg, inherited channelopathies) or acquired (eg, electrolyte derangements) origin. Normal muscle enzyme activities do not rule out a myopathic disorder as the underlying cause of muscle atr...
Clayton HM, Hobbs SJ, Rhodin M, Hernlund E, Peterson M, Bos R, Bragança FS.Prior to international competitions, dressage horses are evaluated for fitness to compete while trotting in hand on a firm surface. This study compares the kinematics of experienced dressage horses trotting under fitness-to-compete conditions vs. performing collected and extended trot when ridden on a sand-fiber arena surface. The hypotheses are that the vertical range of motion (ROM) and left-right asymmetries in minimal and maximal heights of axial body segments at ridden trot exceed those when trotting in hand. Inertial measurement units (IMUs) attached mid-dorsally to the head, withers, an...
Laffi L, Bigand F, Peham C, Novembre G, Gamba M, Ravignani A.Anecdotally, horses' gaits sound rhythmic. Are they really? In this study, we quantified the motor rhythmicity of horses across three different gaits (walk, trot, and canter). For the first time, we adopted quantitative tools from bioacoustics and music cognition to quantify locomotor rhythmicity. Specifically, we tested whether kinematics data contained rhythmic categories; these occur when adjacent temporal intervals are categorically, rather than randomly, distributed. We extracted the motion cycle duration (t) of two ipsilateral hooves from motion data of 13 ridden horses and calculated th...
Seery S, Gardiner J, Bates KT, Pinchbeck G, Clegg P, Ireland JL, Milner PI.Trimming is critical for a functioning equine hoof. Pressure distribution provides information on loading; however, information on the effects of trimming on pressure distribution is lacking. Objective: To describe the pressure changes of equine fore feet following trimming. Methods: Cross-sectional cohort study. Methods: Fifty sound horses were recruited. Eighteen external hoof measures of the dorsal, lateral, medial and solar aspects were obtained before and after trimming from 94 fore feet. Horses were walked over a pressure mat before and after trimming and pressure maps of the solar surfa...
Fikri F, Purnomo A, Maslamama ST, Purnama MTE.In the past 20 years, acupuncture has been utilized as an alternative therapy for equine laminitis despite a lack of clinical evidence to support its effectiveness. Information from previous studies needs to be evaluated holistically to verify the effectiveness of acupuncture. This meta-analysis aimed to comprehensively investigate the effectiveness of acupuncture as a treatment for laminitis in horses. Unassigned: A total of 7 studies out of 145 were selected in the PubMed, Scopus, Cochrane Library, and ProQuest databases using the keywords "equine laminitis," "acupuncture," "horses," and "la...
Yildirim İG, Karaarslan S, Erkan A.Musculoskeletal injuries (MSI) are a major concern in the horse racing industry, often leading to career-ending outcomes. Contributing factors include conformation, limb and joint defects, hoof structure, age, and hard track surfaces. Objective: This study aimed to evaluate the distribution of MSI in Thoroughbred and Arabian racehorses during racing and training, categorised by breed and track surface. Methods: Retrospective cohort study. Methods: The data from 2018 to 2023 were collected at the Turkish Jockey Club's Şirinyer Hippodrome (38°23'03.7″ N 27°09'01.0″ E), covering 553 MSI ca...
Castro D, Clark-Price S.Pre-existing muscle disorders in horses can often be subtle and may only become evident during or after anesthesia. Advancements in veterinary medicine, along with increased knowledge and research in this field, help minimize anesthesia-related problems. Adequate preanesthesia assessment, early disease diagnosis, and proper management are crucial in minimizing risks to the neuromuscular system during general anesthesia.
Schaus K, Wacker J, Jandowsky A, Büttner K, Röcken M, Bartmann CP.Morphometric measurements of the toe serve as a reference for the objective assessment of the presence of a pathological condition and as a guide for the correct trimming of the hooves. Therefore, the anatomical differences between horses and donkeys oblige an autonomous database with reference values for the donkey. The aim of this study was therefore to provide readings of the distal hind limb on radiographs of donkeys. Radiographs of the distal hind limb in two projections of 41 generally sound donkeys without lameness in walk were taken after previous hoof trimming and preparation accordin...
Ferreira CMC, Simões BD, Marques EAS, Carbas RJC, da Silva LFM.Despite technological advancements in various industries, the equine sector still relies on old methods like horseshoeing. Although traditional, the industry is dynamic and well-funded. Therefore, there is a need to modernize these methods with more reliable and less invasive solutions for attaching horseshoes to horse hooves. There are currently several commercial adhesive solutions in the market specifically tailored to this application. In this work, the mechanical properties of two acrylic adhesives were characterized under quasi-static conditions. In the characterization process, tensile,...
Dörner CA, Vargas V, Castellón CH.The aim of this prospective case-control study was to describe and implement a reliable, accurate, and straightforward ultrasound-guided proximo-medial approach technique for injecting the carpal flexor tendon sheath in horses. The proximo-medial ultrasound-guided approach for intrathecal access to the carpal canal, as described in this study, was firstly developed on ten cadaveric limbs using an undiluted ionic iodinated contrast medium. Landmarks were identified, and the access point was established. Subsequently, the technique was validated in ten horses, and its efficacy was compared with ...
Bussiman F, Richter J, Hidalgo J, Silva FFE, Ventura RV, Carvalho RSB, Mattos EC, Ferraz JBS, Eler JP, de Carvalho Balieiro JC.Gait visual scores are widely applied to horse breeding because they are a fast and easy phenotyping strategy, allowing the numeric interpretation of a complex biological process such as gait quality. However, they may suffer from subjectivity or high environmental influence. We aimed to investigate potential causal relationships among six visual gait scores in Campolina horses. The data included 5475 horses with records for at least one of the following traits: Dissociation (Di), Comfort (C), Style (S), Regularity (R), Development (De), and Gait total Scores (GtS). The pedigree comprised thre...
Duarte CR, Raimundo A, Sousa JP, Fernandes O, Santos R.This systematic review aimed to determine the prevalence of lower back pain (LBP) in equestrian athletes (EAs) and identify associated risk factors. Following the PRISMA guidelines, observational studies published between 2004 and 2024 in English, Portuguese, Spanish, and German were included. The review identified relevant studies through the Web of Science, EBSCO, MEDLINE, and SCOPUS (last search performed on 30 October 2024), yielding 14 studies with a total of 4527 participants. The question format for the included studies specified the population as equestrian athletes, the exposure as eq...
Buyck C, Zani DD, Robert M, Gustafsson K.Computed tomography (CT) is increasingly recognized as superior to conventional imaging methods for diagnosing osteomyelitis in foals. However, comprehensive studies in this area are limited. This study aims to report on clinical cases of osteomyelitis in foals, establishing a relationship between CT findings and survival outcomes. Additionally, it compares CT imaging with conventional methods such as radiography and ultrasound. We hypothesized that CT variables would more accurately predict survival than other clinical factors and provide more detailed information about osteomyelitis lesions....
Buyck C, Zani DD, Robert M, Gustafsson K.Computed tomography (CT) is increasingly recognized as superior to conventional imaging methods for diagnosing osteomyelitis in foals. However, comprehensive studies in this area are limited. This study aims to report on clinical cases of osteomyelitis in foals, establishing a relationship between CT findings and survival outcomes. Additionally, it compares CT imaging with conventional methods such as radiography and ultrasound. We hypothesized that CT variables would more accurately predict survival than other clinical factors and provide more detailed information about osteomyelitis lesions....
Costa GL, Tabbì M, Bruschetta G, Spadola F, Leonardi F, Bruno F, Iannelli NM, Licata P, Macrì F, Passino ES, Macrì D, Interlandi C.The study aimed to evaluate the analgesic efficacy of tapentadol in horses, by determining plasma serotonin concentration and adrenocortical response, as biomarkers of pain stress in chronic joint disorders. Thirty-six horses (20 females and 16 males) were divided into three groups of 12 subjects each: group A, osteoarthritis (OA), grade 3-4 lameness; group B, OA, grade 5 lameness; and group C, no OA, no lameness, were enrolled. The orthopedic examination included flexion tests, and radiological and ultrasound examinations. The degree of lameness has been estimated from 0 to 5 according to the...
Cervantes-Sevilla JR, Ramírez-Cervera M, Guzman-Ruvalcaba MJ.Traumatic hemothorax is a serious condition requiring immediate intervention. We present a case of a 48-year-old male professional jockey who suffered traumatic hemothorax, bilateral pulmonary contusions, and multiple rib fractures after being stomped by a horse. Management included intercostal drainage placement, costal fixation from the 5th to the 10th rib, and intensive care unit admission. Postoperative complications included, acute kidney injury, rhabdomyolysis, and severe acute respiratory distress syndrome. This case highlights the importance of a multidisciplinary approach in managing ...
DeBoer M, Rieck T, Johnson L, Redenius H, Martinson K.Horses have become more intensively managed, including the use of hay nets to increase intake time and reduce hay waste, but their impact on health is not well known. The objectives were to compare changes in subluxations, range of motion, and the pain-pressure threshold in the axial skeleton of horses fed hay with (NET) or without (CON) hay nets. In September 2021, 13 adult horses were blocked by bodyweight (BW) and randomly assigned to the NET or CON treatments for one year. After one year, horses switched treatments and the trial concluded in September 2023. Horses were housed in dry lots w...
Blatter M, Chapman HS, Heinzel-Gutenbrunner M, von Plato G, Rijkenhuizen A.Desmotomy of the accessory ligament of the superficial digital flexor tendon (AL-SDFT) has been described for the treatment of superficial digital flexor tendon (SDFT) tendinopathy in Thoroughbred and Standardbred racehorses, and in event horses. To our knowledge, the outcome of this procedure has not been described in a population of warmblood horses. Objective: To report on the outcome of treatment of SDFT tendinopathy in warmblood horses using tenoscopic desmotomy of the main part of the AL-SDFT. Methods: Prospective observational case series. Methods: All 62 horses included in the case ser...
Kneipp MLA, Sousa LN, Cota LO, Malacarne BD, Winter IC, Santana CH, Santos RL, Xavier ABS, Faleiros RR, Carvalho AM.Coxofemoral dysplasia is a condition characterized by the abnormal development and flattening of the femoral head and deformities in the acetabulum, leading to joint instability. Although described in various animal species, it is uncommon and rarely reported in horses. This article presents a case of incapacitating coxofemoral dysplasia diagnosed in a four-month-old foal Mangalarga Marchador, which exhibited lameness in the hind limbs, thoracolumbar kyphosis, gluteal muscle atrophy, and pronounced sensitivity during pelvic limb flexion. The clinical diagnosis indicative of bilateral coxofemor...
Eivers SS, McGivney BA, Gu J, MacHugh DE, Katz LM, Hill EW.Peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) has emerged as a critical control factor in skeletal muscle adaptation to exercise, acting via transcriptional control of genes responsible for angiogenesis, fatty acid oxidation, oxidative phosphorylation, mitochondrial biogenesis and muscle fibre type composition. In a previous study, we demonstrated a significant increase in mRNA expression for the gene encoding PGC-1α (PPARGC1A) in Thoroughbred horse skeletal muscle following a single bout of endurance exercise. In this study, we investigated mRNA expression changes i...
Estberg L, Stover SM, Gardner IA, Johnson BJ, Case JT, Ardans A, Read DH, Anderson ML, Barr BC, Daft BM, Kinde H, Moore J, Stoltz J, Woods LW.To characterize and contrast data from Thoroughbreds that incurred a fatal musculoskeletal injury (FMI; injury resulting in death or euthanasia) during racing or training and data from all California race entrants during a 9-month period in 1991. Methods: Case-control study. Methods: Thoroughbreds that incurred a FMI during racing or training at a California race-meet and all California race entrants from January through June and October through December 1991. Methods: Age and sex were compared with chi 2 and Fisher's exact tests among horses fatally injured while racing and training. A log-li...
Egenvall A, Tranquille CA, Lönnell AC, Bitschnau C, Oomen A, Hernlund E, Montavon S, Franko MA, Murray RC, Weishaupt MA, Weeren vR, Roepstorff L.Orthopaedic, or other, injuries in sports medicine can be quantified using the 'days-lost to training' concept. Both the training regimen and the surface used in training and racing can affect the health of racehorses. Our aim was to associate 'days-lost to training' in elite-level show-jumpers to horse characteristics, training and management strategies, and the time spent working on various training and competition surfaces. We designed a longitudinal study of professional riders in four European countries. Data were recorded using training diaries. Reasons for days-lost were classified into...
Patterson-Kane JC, Firth EC.Despite the high incidence of superficial digital flexor tendon (SDFT) injury in racehorses, the pathobiology of the condition is not clearly defined. The SDFT improves locomotor efficiency by storing elastic energy, but as a result it has low mechanical safety margins. As with the Achilles tendon in humans, rupture during athletic activity often follows accumulation of exercise and age-induced degenerative change that is not repaired by tenocytes. There is limited understanding of tenocyte biology and pathology, including responses to high mechanical strains and core temperatures during exerc...
Sun TC, Riggs CM, Cogger N, Wright J, Al-Alawneh JI.Reports of fractures in racehorses have predominantly focused on catastrophic injuries, and there are limited data identifying the location and incidence of fractures that did not result in a fatal outcome. Objective: To describe the nature and the incidence of noncatastrophic and catastrophic fractures in Thoroughbreds racing at the Hong Kong Jockey Club (HKJC) over seven racing seasons. Methods: Retrospective cohort study. Methods: Data of fractures sustained in horses while racing and of race characteristics were extracted from the HKJC Veterinary Management Information System (VMIS) and Ra...
Barr ED, Pinchbeck GL, Clegg PD, Boyde A, Riggs CM.Thoroughbred racehorses are commonly affected by subchondral bone injury, but the exact prevalence and the distribution of palmar/plantar osteochondral disease (POD) lesions are unknown. The relationship between pathologies has not been elucidated, although it is widely accepted that POD is a manifestation of traumatic overload arthrosis. Objective: There is an association between grade of POD and other pathologies affecting the third metacarpal and metatarsal (MC/MTIII) condyles (wear lines, cartilage loss, marginal remodelling, dorsal impact injuries and linear fissures). Objective: To evalu...
Rivero JL, Serrano AL, Barrey E, Valette JP, Jouglin M.Combined methodologies of enzyme-linked immunosorbent assay (ELISA), sodium dodecyl sulphate polyacrilamide gel electrophoresis (SDS-PAGE), immunoblotting, traditional myofibrillar ATPase (mATPase) histochemistry and immunocytochemistry of whole biopsied samples were used to study myosin heavy chain (MHC) isoforms in the equine gluteus medius muscle. The ELISA technique allowed the quantification of the three MHC isoforms known to be present in different horse muscles: slow (MHC-I) and two fast (termed MHC-IIA and MCH-IIX). The SDS-PAGE method resolved MHCs in three bands: MHC-I, MHC-IIX and M...
Simon EL, Gaughan EM, Epp T, Spire M.To determine the amount of time required for surface temperatures of thoracic and pelvic limbs in horses to return to pre-exercise temperatures after high-speed treadmill exercise, as detected via infrared thermographic imaging. Methods: Prospective study. Methods: 6 Thoroughbreds. Methods: All horses had been trained on and conditioned to use of a high-speed treadmill. Baseline thermographic images were obtained 3 days prior to exercise (baseline). Horses were exercised on a treadmill at a walk for 5 minutes, a slow trot (3 m/s) for 5 minutes, a trot (5 to 6 m/s) for 5 minutes, and a slow gal...
Townsend HG, Leach DH.The anatomical features of 21 equine thoracolumbar spines, obtained from horses with clinically normal backs, were examined and the results compared with recent data on the mobility of the joint complexes of the horse's spine. The thoracolumbar spine can be divided into four regions based upon the morphology of the joint complexes: the first thoracic intervertebral joint (T1-2), the cranial and mid thoracic region (T2-T16), the caudal thoracic and lumbar region (T16-L6) and the lumbosacral joint. The mobility of the intervertebral joints in each of these regions can be related to their morphol...
Martin RB, Lau ST, Mathews PV, Gibson VA, Stover SM.We studied birefringence as an indicator of collagen fiber orientation in the diaphysis of the equine third metacarpal bone. We had previously shown that tissue from the lateral cortex of this bone is stronger monotonically, but less fatigue resistant, than tissue from the medial and dorsal regions. To learn whether collagen fiber orientation might play a role in this regional specialization, we tested three hypotheses using the same specimens: (1) collagen fiber orientation is regionally dependent; (2) remodeling changes collagen fiber orientation; (3) longitudinal collagen fibers correlate p...
Wennerstrand J, Johnston C, Roethlisberger-Holm K, Erichsen C, Eksell P, Drevemo S.Earlier studies have developed a clinical tool to evaluate objectively the function of the equine back. The ability to differentiate horses with back pain from asymptomatic, fully functioning horses using kinematic measures from this tool has not been evaluated. Objective: To compare the kinematics of the back at walk and trot in riding horses with back dysfunction to the same parameters in asymptomatic sport horses. Methods: The kinematics of the back in 12 horses with impaired performance and back pain were studied at walk and trot on a treadmill. Data were captured for 10 sees at 240 Hz. Ra...
Birn-Jeffery AV, Higham TE.Animals must continually respond dynamically as they move through complex environments, and slopes are a common terrain on which legged animals must move. Despite this, non-level locomotion remains poorly understood. In this study, we first review the literature on locomotor mechanics, metabolic cost, and kinematic strategies on slopes. Using existing literature we then performed scaling analyses of kinematic variables, including speed, duty factor, and stride-length across a range of body sizes from ants to horses. The studies that examined locomotion on inclines vastly outnumbered those focu...
Blumer R, Maurer-Gesek B, Gesslbauer B, Blumer M, Pechriggl E, Davis-López de Carrizosa MA, Horn AK, May PJ, Streicher J, de la Cruz RR, Pastor ÁM.To test whether palisade endings are a general feature of mammalian extraocular muscles (EOMs). Methods: Thirteen species, some frontal-eyed (human, monkey, cat, and ferret), and others lateral-eyed (pig, sheep, calf, horse, rabbit, rat, mouse, gerbil, and guinea pig) were analyzed. Palisade endings were labeled by using different combinations of immunofluorescence techniques. Three-dimensional reconstructions of immunolabeled palisade endings were done. Results: In all frontal-eyed species, palisade endings were a consistent feature in the rectus EOMs. Their total number was high and they exh...
Riemersa DJ, Schamhardt HC.A clamp designed for holding tendons in force/elongation studies is described. No slippage occurred when tensile forces up to 13,800 N were applied to horses digital flexor tendons fixed in this clamp.
Clegg PD.Tendon and ligament injuries continue to be one of the most frequent causes of orthopaedic injury and early retirement in the Thoroughbred racehorse. In the UK, the Horserace Betting Levy Board has invested considerable research funding in the last decade in order to investigate aspects of tendon epidemiology, biology and therapy, in order to decrease both the welfare and economic consequence of such injuries. This review summarises key aspects of this research effort and identifies specific research directions for the future.
Klein DJ, McKeever KH, Mirek ET, Anthony TG.The athletic horse, despite being over 50% muscle mass, remains understudied with regard to the effects of exercise and training on skeletal muscle metabolism. To begin to address this knowledge gap, we employed an untargeted metabolomics approach to characterize the exercise-induced and fitness-related changes in the skeletal muscle of eight unconditioned Standardbred horses (four male, four female) before and after a 12-week training period. Before training, unconditioned horses showed a high degree of individual variation in the skeletal muscle metabolome, resulting in very few differences ...
Innes JF, Clegg P.Examples of naturally occurring musculoskeletal disorders are extremely common in veterinary species and provide a valuable comparative research resource, which can provide compelling comparative data on the aetiopathogenesis and treatment of many common human musculoskeletal diseases. In particular, orthopaedic diseases are a common morbidity in both dogs and horses. In this review, we give an overview of the common musculoskeletal diseases encountered in these species: for instance, tendon and ligament injuries, arthropathies and stress fractures, as well as an insight into the basic biology...
Maliye S, Voute LC, Marshall JF.This study aimed to quantify the compensatory response to naturally-occurring forelimb lameness on load redistribution. Data from lameness investigations using an inertial sensor based system to monitor the response to forelimb diagnostic anaesthesia were reviewed. Horses with primary forelimb lameness were grouped for analysis as (1) all horses combined (n= 28), (2) forelimb-only lameness (n= 8/28), (3) forelimb-contralateral hindlimb lameness (n= 14/28), (4) forelimb-ipsilateral hindlimb lameness (n= 6/28). The effect of diagnostic anaesthesia on measures of head and pelvic movement ...
Anderson JR, Phelan MM, Foddy L, Clegg PD, Peffers MJ.Osteoarthritis is an age-related degenerative musculoskeletal disease characterized by loss of articular cartilage, synovitis, and subchondral bone sclerosis. Osteoarthritis pathogenesis is yet to be fully elucidated with no osteoarthritis-specific biomarkers in clinical use. equine cartilage explants ( = 5) were incubated in tumor necrosis factor-α (TNF-α)/interleukin-1β (IL-1β)-supplemented culture media for 8 days, with the media removed and replaced at 2, 5, and 8 days. Acetonitrile metabolite extractions of 8 day cartilage explants and media samples at all time points underwent one-d...
White A, Estrada M, Walker K, Wisnia P, Filgueira G, Valdés F, Araneda O, Behn C, Martínez R.During exercise, the oxygen consumption and the production of free radicals increase and can lead to oxidative stress with a deleterious effect on cellular structures involved in physical activity. To evaluate the oxidative stress produced by exercise and the role of ascorbate as an antioxidant, venous blood samples were obtained from 44 thoroughbred racehorses, before and after a 1000+/-200-m race at maximum velocity. Fourteen of these horses were treated intravenously with 5 g of ascorbate before running. Antioxidant capacity (PAOC), endogenous and exogenous ascorbate concentration, total an...
Schuurman SO, Kersten W, Weijs WA.Horses spend much of their life standing, and they are believed to be able to keep their limbs straight without muscular effort. We tested the hypothesis that the stifle (knee) and hock (tarsal) joints could be stabilized merely with the help of a passive lock mechanism whereby the patella is secured behind a hook, formed by the medial femoral trochlea. In anaesthetized animals and isolated limbs the stifle and hock flex readily under compression. In isolated limbs this collapse was prevented by a small force applied to the patella, mimicking the action of the vastus medialis muscle. In vivo, ...
Hobbs SJ, Clayton HM.The aims of this study were to measure ground reaction forces (GRFs) of concurrently loaded limbs and to evaluate spatial relationships between the centre of pressure (COP) and centre of mass (COM) in trotting horses. Kinematic (120Hz) and GRF data were collected at trot from three trials of eight horses using four force plates (960 Hz). Forelimb and hind limb GRFs were measured, COP was calculated from the resultant vertical GRF vector and COM was calculated by summation of weighted segmental COMs. Peak total vertical force (19.3 ± 1.3N/kg at 45.1 ± 2.3% diagonal stance) coincided with zero...
O'Brien C, Marr N, Thorpe C.The forelimb superficial digital flexor tendon (SDFT) is an energy-storing tendon that is highly susceptible to injury during activities such as galloping and jumping, such that it is one of the most commonly reported causes of lameness in the performance horse. This review outlines the biomechanical and biothermal effects of strain on the SDFT and how these contribute to the accumulation of microdamage. The effect of age-related alterations on strain response and subsequent injury risk is also considered. Given that tendon is a slowly healing and poorly regenerative tissue, prompt detection o...
Lyle CH, Blissitt KJ, Kennedy RN, Mc Gorum BC, Newton JR, Parkin TD, Stirk A, Boden LA.Sudden death adversely affects racehorse welfare, jockey safety and the public perception of horseracing. Objective: To describe the risk of racing-associated sudden death in Thoroughbred racehorses in the UK from 2000 to 2007, to identify whether there were risk factors uniquely associated with sudden death and to improve the understanding of the pathogenesis of racing-associated sudden death by identification of risk factors for such cases. Methods: A sudden death was defined as an acute collapse and death, in an apparently healthy Thoroughbred racehorse, during or immediately after racing, ...
Chiaradia E, Avellini L, Rueca F, Spaterna A, Porciello F, Antonioni MT, Gaiti A.Since it has been suggested that lipid peroxidation following free radical overproduction may be one of the causes of physical exercise-induced myopathies and hemolysis in horses, we looked for the possible relationships between these phenomena and muscle fiber damage. We use a homogeneous group of Maremmana stallions which, after a 3-month training period, underwent a series of physical exercises of increasing intensity. We determined the contents of malondialdehyde (MDA), one of the main lipid peroxidation end-products, and glutathione the substrate of one of the most important free radical ...
Sullivan KA, Hill AE, Haussler KK.Common methods used to treat back problems in horses need to be assessed objectively. Objective: To measure spinal mechanical nociceptive thresholds (MNTs) and evaluate the effects of chiropractic, massage and phenylbutazone, compared with active and inactive control groups. Methods: Baseline MNTs at 7 sites within the thoracolumbar and sacral regions were measured in 38 healthy mature horses exhibiting no clinical signs of lumbar pain. Horses were assigned to one of 3 treatment groups: instrument-assisted chiropractic treatment, therapeutic massage and phenylbutazone; or 2 control groups: rid...
Dutto DJ, Hoyt DF, Clayton HM, Cogger EA, Wickler SJ.The net work of the limbs during constant speed over level ground should be zero. However, the partitioning of negative and positive work between the fore- and hindlimbs of a quadruped is not likely to be equal because the forelimb produces a net braking force while the hindlimb produces a net propulsive force. It was hypothesized that the forelimb would do net negative work while the hindlimb did net positive work during trotting in the horse. Because vertical and horizontal impulses remain unchanged across speeds it was hypothesized that net work of both limbs would be independent of speed. ...
Canè V, Botti P, Soana S.The influence of pulsed low-frequency electromagnetic fields (PEMFs) on bone formation was investigated in studies of the healing process of transcortical holes, bored at the diaphyseal region of metacarpal bones of six adult horses, exposed for 30 days to PEMFs (28 G peak amplitude, 1.3 ms rise time, and 75 Hz repetition rate). A pair of Helmholtz coils, continuously powered by a pulse generator, was applied for 30 days to the left metacarpal bone, through which two holes, of equal diameter and depth, had been bored at the diaphyseal region. Two equal holes, bored at the same level in the rig...
Peham C, Kotschwar AB, Borkenhagen B, Kuhnke S, Molsner J, Baltacis A.The aim of the study was to compare the stability of the rider as well as the forces acting on a horse's back with different seating positions at the trot (sitting trot, rising trot and two-point seat). The same experienced rider was mounted on 10 sound horses trotting on a treadmill. The kinetic data were recorded with an electronic pressure mat, placed under a well-fitting dressage saddle with no saddle pad. The rider used three different seating positions, each for 20 s. Right forelimb motion was used to synchronise the pressure data with the stride cycles. To determine the rider's stabilit...
Côté GP, Smillie LB.Whereas skeletal muscle tropomyosin binds strongly to muscle F-actin in a buffer containing 30 mM KCl and 1-2 mM free Mg2+, equine platelet tropomyosin only binds stoichiometrically (1 tropomyosin molecule per 6 actin monomers) at higher Mg2+ concentrations (7-8 mM free Mg2+). At low free Mg2+ concentrations (1.5 mM) the binding of the platelet protein is only marginally increased by raising the KCl concentration to an optimal value (0.10-0.20 M). This weaker binding can be attributed to the relatively poor head-to-tail polymerization of platelet tropomyosin and its fewer actin-binding sites. ...
