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.
Taylor SE, Vaughan-Thomas A, Clements DN, Pinchbeck G, Macrory LC, Smith RK, Clegg PD.There is a paucity of data regarding molecular markers that identify the phenotype of the tendon cell. This study aims to quantify gene expression markers that distinguish between tendon fibroblasts and other mesenchymal cells which may be used to investigate tenogenesis. Methods: Expression levels for 12 genes representative of musculoskeletal tissues, including the proposed tendon progenitor marker scleraxis, relative to validated reference genes, were evaluated in matched samples of equine tendon (harvested from the superficial digital flexor tendon), cartilage and bone using quantitative P...
Goodrich LR, McIlwraith CW.Arthroscopic complications are infrequent but when they occur can cause significant morbidity in the equine patient. This article reviews intraoperative and postoperative complications along with ways to avoid them. Additionally, therapeutic methods of managing these complications also are discussed.
Goodrich LR.Equine orthopedic pain management has become a growing area of interest. Its importance has been emphasized in many studies showing that better pain management results in decreased postoperative complications such as chronic pain, support-limb laminitis, gastric ulceration, and gastrointestinal disease. This review is meant for the surgeon managing orthopedic pain pre-, peri-, and postoperatively.
Baxter GM, Morrison S.The most common and significant complication of excessive unilateral weight bearing in adult horses is support limb laminitis. Young horses with unilateral lameness problems develop support limb laminitis infrequently compared with adult horses.
van Grevenhof EM, Schurink A, Ducro BJ, van Weeren PR, van Tartwijk JM, Bijma P, van Arendonk JA.Osteochondrosis (OC) is an important orthopedic developmental disorder in many horse populations. A review of the literature revealed widely variable heritability estimates for the disorder. We estimated the genetic variables (heritabilities and genetic correlations) of various manifestations of OC. Femoropatellar, tarsocrural, and metacarpophalangeal and metatarsophalangeal joints of 811 randomly selected yearlings from the Royal Warmblood Studbook of The Netherlands, descending from 32 representative stallions, were scored for OC at 28 predilection sites. At each site, OC was scored in 5 cat...
Aleman M, Nieto JE, Magdesian KG.Anesthetic-induced malignant hyperthermia (MH) has been documented in Quarter Horses with a single point mutation in the ryanodine receptor 1 gene (RyR1) at nucleotide C7360G, generating a R2454G amino acid substitution. However, there have been no reports of nonanesthetic manifestations of MH in horses with the C7360G mutation. Objective: To describe clinical manifestations of Quarter Horses with the C7360G mutation. Methods: Eleven Quarter Horses with the RyR1 C7360G mutation. Methods: This prospective study included horses with suspected MH, undetermined etiology of sudden death, death with...
Dyson PK, Jackson BF, Pfeiffer DU, Price JS.The first major epidemiological study of injury incidence in the UK flat racing Thoroughbred (TB), published in 1985, found lameness to be the single largest reason for days when horses failed to train. It was considered advisable to ascertain if progress has been made in reducing the problem of musculoskeletal injuries in the intervening period. Objective: To quantify injury incidence and days lost from training by 2- and 3-year-old TBs in UK training yards during 2002 and 2003. Methods: One-hundred-and-eighty-two yearling TBs were recruited at the end of 2001 and daily training and injury re...
Moger CJ, Arkill KP, Barrett R, Bleuet P, Ellis RE, Green EM, Winlove CP.An investigation of collagen fiber reorientation, as well as fluid and matrix movement of equine articular cartilage and subchondral bone under compressive mechanical loads, was undertaken using small angle X-ray scattering measurements and optical microscopy. Small angle X-ray scattering measurements were made on healthy and diseased samples of equine articular cartilage and subchondral bone mounted in a mechanical testing apparatus on station ID18F of ESRF, Grenoble, together with fiber orientation analysis using polarized light and displacement measurements of the cartilage matrix and fluid...
Oki H, Miyake T, Kasashima Y, Sasaki Y.The superficial digital flexor tendon (SDFT) injury causes considerable wastage of racing Thoroughbreds. In this study, the heritability of SDFT injury of the forelimbs was estimated in the Thoroughbred racehorses based on the Bayesian analysis with Gibbs sampling using threshold animal models. New horse patients of SDFT injury at the age of 2-5 years accommodated in the training centers in 2005 were used for the analyses. Based on clinical data of 8198 horses, heritability of SDFT was estimated to be the order of 0.17 (posterior mode) to 0.19 +/- 0.05 (posterior mean +/- posterior SD).
Kelly JR, Carmalt J, Hendrick S, Wilson DG, Shoemaker R.To compare biomechanical properties of 6 suture configurations using a large diameter polyester prosthesis in the muscular process (MP) of the arytenoid cartilage and to determine failure mode. Methods: Experimental study. Methods: Cadaveric equine larynges (n=121). Methods: Suture configurations (4 single, 2 double) were inserted, and then constructs were tested in a single-cycle to failure at a 100 mm/min distraction. Load deformation curves were generated to assess the biomechanical properties of each construct. A 1-way ANOVA was used to compare the mean differences in construct failure for...
Noble P, Collin B, Lecomte-Beckers J, Magnée A, Denoix JM, Serteyn D.This study describes an equine joint friction test using a cartilage-on-cartilage arrangement and investigates the influence of age and load on the frictional response. Osteochondral plugs were extracted from equine shoulder joints (2-5 years, n=12; 10-14 years, n=15), and mounted in a pin-on-disc tribometer. The frictional response was then measured under constant conditions (2N; 20 degrees C; 5 mm/s), and with increasing load (2N, 5N, 10N). In all experiments, the friction coefficient of young cartilage was significantly (P<0.001) smaller than obtained from old cartilage, while the applicati...
Chateau H, Robin D, Simonelli T, Pacquet L, Pourcelot P, Falala S, Denoix JM, Crevier-Denoix N.Properties of ground surfaces condition locomotion, and quality of track surfaces is believed to be involved in the pathogenesis of many musculoskeletal injuries in the horse. Measuring ground reaction forces (GRF) is an interesting approach to assess those interactions. Forceplates are the most commonly used but they are not well suited to compare different ground surfaces at fast gaits. Embarked equipment, fixed under the horse's hoof, would allow force measurement on any track. The objective of this work was (1) to design a device which enables the measurement of 3-D GRF on any ground, at a...
Inoue Y, Matsui A, Asai Y, Aoki F, Yoshimoto K, Matsui T, Yano H.We studied the response of biochemical markers of bone metabolism to exercise intensity in horses. Four horses were walked on a mechanical walker for one week (pre-exercise). Then they performed low-speed exercise on a high-speed treadmill in the first week and medium-speed exercise in the second week and high-speed exercise in the third week of training. We measured two indices of bone resorption, serum hydroxyproline concentration and the urinary deoxypyridinoline/creatinine ratio, and serum osteocalcin (OC) concentration as an index of bone formation. Both indices of bone resorption gradual...
van Schie HT, Bakker EM, Cherdchutham W, Jonker AM, van de Lest CH, van Weeren PR.To evaluate quantitative ultrasonography for objective monitoring of the healing process and prognostication of repair quality in equine superficial digital flexor (SDF) tendons. Methods: 6 horses with standardized surgical lesions in SDF tendons of both forelimbs. Methods: Healing was monitored for 20 weeks after surgery by use of computerized ultrasonography. Pixels were categorized as C (intact fasciculi), B (incomplete fasciculi), E (accumulations of cells and fibrils), or N (homogenous fluid or cells). Four scars with the best quality of repair (repair group) and 4 scars with the lowest q...
Nunamaker DM, Nash RA.To report development, configuration, application, and results of a tapered-sleeve transcortical pin external skeletal fixation device (TSP ESFD) for use on fractures of the distal aspect of the equine limb. Methods: Optimization analysis of a TSP ESFD was carried out with mechanical testing and review of clinical case outcomes. Methods: Cadaveric adult third metacarpal bones (MC3) for mechanical testing; horses (n=7) with severely comminuted proximal (6; P1) or second (1) phalanx fractures. Methods: Mechanical testing of methods for attachment of TSP to the sidebars were tested as well as opt...
Nauwelaerts S, Kaiser L, Malinowski R, Clayton HM.The estimation of the position of the center of mass (CM) is essential in a wide range of biomechanical analyses. In horses, the majority of the body mass is contained in the trunk and in most studies, the trunk is assumed to be rigid. However, this rigidity assumption has not been tested. We quantified changes in the position of the trunk CM due to external shape changes by measuring the kinematics of a mesh encompassing the trunk. Using a frame of reference fixed to the horse's spine, we described the shape deformation of the trunk during walking. In addition, we tested for speed and individ...
Muir P, Peterson AL, Sample SJ, Scollay MC, Markel MD, Kalscheur VL.Repetitive bone injury and development of stress fracture is a common problem in humans and animals. The Thoroughbred racehorse is a model in which adaptive failure and associated development of stress fracture is common. We performed a histologic study of the distal end of the third metacarpal bone in two groups of horses: young Thoroughbreds that were actively racing (n = 10) and a group of non-athletic horses (n = 8). The purpose of this study was to determine whether development of articular microcracks was associated with specific alterations to subchondral plate osteocytes. Morphometric ...
Cogger N, Evans DL, Hodgson DR, Reid SW, Perkins N.To describe the incidence rate of musculoskeletal (MS) injuries and investigate the factors that influence recovery from MS injury in young Thoroughbred horses in Australia. Methods: Training and injury data were collected at fortnightly intervals from 14 trainers in New South Wales. Incidence rates were calculated for initial injuries stratified by age-class and sex. Survival analysis methods were used to investigate the time to recovery after the first MS injury (measured as a start in a race or barrier trial). Results: For the 248 racehorses enrolled, there were 428 injuries recorded; 2-yea...
Miró F, Santos R, Garrido-Castro JL, Galisteo AM, Medina-Carnicer R.The handled trot of three Lusitano Purebred stallions was analyzed by using 2D and 3D kinematical analysis methods. Using the same capture and analysis system, 2D and 3D data of some linear (stride length, maximal height of the hoof trajectories) and angular (angular range of motion, inclination of bone segments) variables were obtained. A paired Student T-test was performed in order to detect statistically significant differences between data resulting from the two methodologies With respect to the angular variables, there were significant differences in scapula inclination, shoulder angle, c...
Smith S, Dyson SJ, Murray RC.Distal sesamoidean ligament injury is a recognized cause of lameness but diagnosis using ultrasonography is sometimes difficult. Herein, we describe the normal appearance of the distal sesamoidean ligaments on magnetic resonance (MR) images and the changes that occur when the ligaments are injured. The appearance of the distal sesamoidean ligaments on MR images from 66 control horses and 58 horses with distal sesamoidean desmitis were described and the cross-sectional area and signal intensity of the ligaments measured. In control horses, the ligaments had a characteristic appearance and stron...
Fernandez-Fuente M, Ames EG, Wagner ML, Zhou H, Strom M, Zammit PS, Mickelson JR, Muntoni F, Brown SC, Piercy RJ.To develop a reliable method for converting cultured equine skin-derived fibroblasts into muscle cells. Methods: Equine skin-derived fibroblasts. Methods: The equine myogenic differentiation 1 (eqMyoD) genomic sequence was obtained by use of equine bacterial artificial chromosome screening and PCR sequencing. Total mRNA was extracted from foal skeletal muscle, and eqMyoD cDNA was cloned into a plasmid vector with an internal ribosomal entry site to express bicistronic eqMyoD or enhanced green fluorescent protein (EGFP). Transient expression was confirmed by immunocytochemical analysis and west...
McCue ME, Valberg SJ, Jackson M, Borgia L, Lucio M, Mickelson JR.In this study we examined a family of Quarter Horses with Polysaccharide Storage Myopathy (PSSM) with a dominant mutation in the skeletal muscle glycogen synthase (GYS1) gene. A subset of horses within this family had a more severe and occasionally fatal PSSM phenotype. The purpose of this study was to identify a modifying gene(s) for the severe clinical phenotype. A genetic association analysis was used to identify RYR1 as a candidate modifying gene. A rare, known equine RYR1 mutation, associated with malignant hyperthermia (MH), was found to segregate in this GYS1 PSSM family. Retrospective ...
Dunbar DC, Macpherson JM, Simmons RW, Zarcades A.Segmental kinematics were investigated in horses during overground locomotion and compared with published reports on humans and other primates to determine the impact of a large neck on rotational mobility (> 20 deg.) and stability (< or = 20 deg.) of the head and trunk. Three adult horses (Equus caballus) performing walks, trots and canters were videotaped in lateral view. Data analysis included locomotor velocity, segmental positions, pitch and linear displacements and velocities, and head displacement frequencies. Equine, human and monkey skulls and cervical spines were measured to estimate...
Stock KF, Distl O.Information on 26 434 German Warmblood horses born between 1992 and 2001 was used for multivariate genetic analyses of radiographic health, conformation and performance traits to compare different modes of single- and multiple-trait selection of sires. Results of standardized radiological examinations of 5155 Hanoverian Warmblood horses, conformation evaluations from studbook inspections of 20 603 mares, and performance evaluations from mare performance tests and auction horse inspections of 16 098 horses were used for multivariate genetic analyses. Genetic parameters were estimated with restr...
Knecht S, Luechinger R, Boesiger P, Stüssi E.The mechanical property of articular cartilage determines to a great extent the functionality of diarthrodial joints. Consequently, the early detection of mechanical and, thus, functional changes of cartilage is crucial for preventive measures to maintain the mobility and the quality of life of individuals. An alternative to conventional mechanical testing is the inverse finite element approach, enabling non-destructive testing of the tissue. We evaluated a method for the assessment of the equilibrium material properties of the patellar cartilage based on magnetic resonance imaging during pate...
Egenvall A, Lönnell C, Roepstorff L.The incidence of disease, mortality and survival of horses, focusing on locomotor problems, at riding schools were studied, using data from an animal insurance database during 1997-2002. In total 5140 horses from 136 riding schools were included in the analysis. The overall yearly incidence rate (IR) was 1584 events of veterinary care per 10,000 horse-years at risk (HYAR). The total and diagnostic mortalities were 790 and 763 deaths per 10,000 HYAR. Rates varied substantially among riding schools. For locomotor problems the rates were 1116 events of veterinary care and 524 deaths per 10,000 HY...
Manso Filho HC, McKeever KH, Gordon ME, Costa HE, Lagakos WS, Watford M.Glutamine is the most abundant free alpha-AA in the mammalian body, and large amounts of glutamine are extracted by both the fetus during pregnancy and the mammary gland during lactation. The work presented here addressed the hypothesis that there would be major changes in glutamine metabolism in the mare during the transition period, the time between late gestation, parturition, and early lactation. Eight foals were born to Standardbred mares provided with energy and protein at 10% above NRC recommendations, and foals remained with mares for 6 mo. During lactation, lean body mass decreased by...
Pagliara E, Pasinato A, Valazza A, Riccio B, Cantatore F, Terzini M, Putame G, Parrilli A, Sartori M, Fini M, Zanetti EM, Bertuglia A.A catastrophic fracture of the radial carpal bone experienced by a racehorse during a Palio race was analyzed. Computational modelling of the carpal joint at the point of failure informed by live data was generated using a multibody code for dynamics simulation. The circuit design in a turn, the speed of the animal and the surface characteristics were considered in the model. A macroscopic examination of the cartilage, micro-CT and histology were performed on the radio-carpal joint of the limb that sustained the fracture. The model predicted the points of contact forces generated at the level ...
Valdés-Vázquez MA, McClure JR, Oliver JL, Ramirez S, Seahorn TL, Haynes PF.A sutured tenorrhaphy technique that incorporated an autologous tendon graft was compared mechanically and histologically with a sutured tenorrhaphy at 6, 12, and 24 weeks after repair. Tenorrhaphy was performed in the forelimb tendon of the deep digital flexor muscle and the graft was taken from the hindlimb tendon of the lateral digital extensor muscle; one forelimb site included the graft, whereas the other forelimb site was not grafted. Tenotomies were made immediately proximal to the insertion of the accessory ligament into the tendon of the deep digital flexor muscle. Grafted and nongraf...
Essig CM, Merritt JS, Stubbs NC, Clayton HM.To determine the magnitude and location of skin movement attributable to the cutaneus trunci muscle reflex in response to localized stimulation of the skin of the dorsolateral aspect of the thoracic wall in horses. Methods: 8 horses. Methods: A grid of 56 reflective markers was applied to the lateral aspect of the body wall of each horse; markers were placed at 10-cm intervals in 7 rows and 8 columns. A motion analysis system with 10 infrared cameras was used to track movements of the markers in response to tactile stimulation of the dorsolateral aspect of the thoracic wall at the levels of T6...
Leśniak KG, Williams JM.Directionality of limb and facial asymmetries in nonelite equine populations has been previously reported with results indicating strong similarities to those reported in racehorses. This investigation aimed to consider the relationship between the magnitude of the asymmetries presented within the general equine population, and their previously reported directionality. Direct measurements of 15 bilateral traits (four facial and 11 limb) were captured from a mixed population of 100 horses and ponies. The pooled (whole) population was considered further as horse (withers height >148 cm) and ...
Mollenhauer HH, Rowe LD, Witzel DA.Heart, diaphragm, and rear limb muscle from ponies and rats treated with monensin were examined by light and electron microscopy. In both species, mitochondrial aberrations were observed in selected muscle cells. The aberrations consisted of loss of matrix substance (vacuolization) usually accompanied by swelling. Vacuolated mitochondria were characterized by an almost total loss of matrix substance with retention of the rudimentary cristae form. In ponies, most vacuolated mitochondria were observed in heart muscle though some also were found in the diaphragm. In rats, most vacuolated mitochon...
Ambache N, Killick SW.1 Graded motor responses were elicited in isolated, desheathed, thin strips of dog, horse, pig and sheep retractor penis (RP) muscles by field stimulation with trains of 0.2 ms pulses at 10 hertz. These twitches were shown to be neurogenic in all four species, by their prompt extinction in tetrodotoxin.2 alpha-Adrenoceptor blocking drugs abolished the contractile response to noradrenaline and to tyramine in all four species.3 Motor transmission was wholly adrenergic in the horse as in the dog RP because phentolamine rapidly abolished the electrically induced twitches in both these species; but...
Banse HE, Holbrook TC, Frank N, McFarlane D.Local (skeletal muscle and adipose) and systemic inflammation are implicated in the development of obesity-associated insulin resistance in humans. In horses, obesity is neither strongly nor consistently associated with systemic inflammation. The role of skeletal muscle inflammation in the development of insulin dysregulation (insulin resistance or hyperinsulinemia) remains to be determined. We hypothesized that skeletal muscle inflammation is related to obesity-associated hyperinsulinemia in horses. Thirty-five light-breed horses with body condition scores (BCSs) of 3/9 to 9/9 were studied, i...
Jansen MO, van Buiten A, van den Bogert AJ, Schamhardt HC.The in vivo strains of the musculus interosseus medius (suspensory ligament) and its rami extensorii (extensor branches) in the forelimb of the horse were determined from angular changes of the metacarpophalangeal and the distal interphalangeal joints. For this purpose, regression models were fitted to strains and joint angle combinations measured in in vitro limb loading experiments. The in vivo strains were computed from the kinematics of 8 horses at the walk, the trot and the canter. It was found that the extensor branches were strained about 1.0% at hoof impact, which indicates that they p...
Lagier R.Spinal hyperostosis, an anatomical and radiological concept primarily described in man, is characterized by enthesopathic bony overgrowth on vertebral bodies in the form of spurs or intervertebral bridges. It can also be part of a more diffuse enthesopathic condition, including the appendicular skeleton. These changes are distinct from those of osteoarthrosis. Similar changes can be observed in all kinds of mammals, independent of their type of locomotion (bipodic, quadrumanous, quadrupedic, or aquatic). An anatomical and radiological study is presented of six cases (with histological examinat...
Walter I.Uterine tubes from cow, sheep, horse, pig, dog, cat, rabbit, and guinea pig were examined immunohistochemically for presence and distribution of contractile cells in the mucosal lamina propria. We tested for the presence of alpha-smooth muscle actin, tropomyosin, desmin, smooth muscle myosin (heavy chain) and cytoskeletal proteins vimentin and cytokeratin. Immunostaining for alpha-smooth muscle actin showed two distribution patterns: either positive cells were freely dispersed in the mucosal lamina propria or a distinct subepithelial layer of positive cells was seen. The first distribution pat...
Gamucci F, Pallante M, Molle S, Merlo E, Bertuglia A.Superficial skeletal muscle activation is associated with an electric activity. Bidimensional High-Density Surface Electromyography (HD-sEMG) is a non-invasive technique that uses a grid of equally spaced electrodes applied on the skin surface to detect and portray superficial skeletal muscle activation. The goal of the study was to evaluate the feasibility of HD-sEMG to detect electrical activation of skeletal muscle and its application during rehabilitation exercises in horses. To fulfil this aim, activation of the superficial descending pectoral and external abdominal oblique core muscles w...
Ferrari G, Pang LY, De Moliner F, Vendrell M, Reardon RJM, Higgins AJ, Chopra S, Argyle DJ.Bleomycin is a chemotherapy agent that, when administered systemically, can cause severe pulmonary toxicity. Bleosome is a novel formulation of bleomycin encapsulated in ultra-deformable (UD) liposomes that may be applicable as a topical chemotherapy for diseases such as non-melanoma skin cancer. To date, the ability of Bleosome to effectively penetrate through the skin has not been evaluated. In this study, we investigated the ability of Bleosome to penetrate through ex vivo skin explants from dogs and horses. We visualized the penetration of UD liposomes through the skin by transmission elec...
Ward TL, Valberg SJ, Gallant EM, Mickelson JR.To determine whether an alteration in calcium regulation by skeletal muscle sarcoplasmic reticulum, similar to known defects that cause malignant hyperthermia (MH), could be identified in membrane vesicles isolated from the muscles of Thoroughbreds with recurrent exertional rhabdomyolysis (RER). Methods: Muscle biopsy specimens from 6 Thoroughbreds with RER and 6 healthy (control) horses. Methods: RER was diagnosed on the basis of a history of > 3 episodes of exertional rhabdomyolysis confirmed by increases in serum creatine kinase (CK) activity. Skeletal muscle membrane vesicles, prepared by ...
Estrada R, Chaves F, Robles A, Rojas E, Segura E, Gutiérrez JM.Blood components were studied in six horses immunized with snake venoms for the production of polyvalent antivenom in Costa Rica. No significant changes in hemoglobin or hematocrit throughout the immunization period were observed, whereas a significant increment in total serum proteins occurred in the second half of the immunization process, probably due to an increased synthesis of immunoglobulins. There were no significant changes in creatine kinase, but a slight increment was detected in both transaminases, although they did not exceed normal limits. These findings suggest the absence of re...
Lee S, Baker ME, Clinton M, Taylor SE.Despite many recent advances in imaging and epidemiological data analysis, musculoskeletal injuries continue to be a welfare issue in racehorses. Peptide biomarker studies have failed to consistently predict bone injury. Molecular profiling studies provide an opportunity to study equine musculoskeletal disease. A systematic review of the literature was performed using preferred reporting items for systematic reviews and meta-analyses protocols (PRISMA-P) guidelines to assess the use of miRNA profiling studies in equine and human musculoskeletal injuries. Data were extracted from 40 papers betw...
Ronchetti A, Day P, Weller R.Horses that had been trimmed and shod by apprentice farriers were sourced from the Royal School of Military Engineering, Melton Mowbray (37 horses) and from the Household Cavalry, Knightsbridge (54 horses). The lateral and medial hoof wall angles of both forelimbs were measured using a Ruidoso hoof gauge by the same operator. The difference between the lateral and medial hoof wall angles for each horse was calculated and the results were compared between right-handed and left-handed farriers using the Mann-Whitney U test (P<0.05). There was a significant difference in the mediolateral hoof bal...
Dirikolu L, Woods WE, Boyles J, Lehner AF, Harkins JD, Fisher M, Schaeffer DJ, Tobin T.Injuries sustained by horses during racing have been considered as an unavoidable part of horse racing. Many factors may be associated with the musculoskeletal injuries of Thoroughbred race horses. This study surveyed the amounts of nonsteroidal anti-inflammatory agents (NSAIDs) in injured horse's biological system (plasma) at Kentucky racetracks from January 1, 1995 through December 31, 1996. During that period, there were 84 catastrophic cases (euthanized horses) and 126 noncatastrophic cases. Plasma concentrations of NSAIDs were determined by High Performance Liquid Chromatography in injure...
Pusterla N, Madigan JE.The U.C. Davis Large Animal Lift (LAL) is a lightweight sling developed to help lift horses in clinical and rescue situations. Here we report on its first use in 16 recumbent horses with neurologic, muscular and musculoskeletal disorders. For each horse, history, sedation, ease and time of LAL application and hoisting, standing ability, LAL tolerance and outcome were recorded. The LAL was easily and safely applied in all horses in less than five minutes and the procedure was well tolerated with minimal to no sedation. While 10 horses were able to stand in the LAL after being hoisted, 6 horses ...
Dowling BA, Dart AJ, Hodgson DR, Rose RJ, Walsh WR.To evaluate the effect of recombinant equine growth hormone (rEGH) on the in vitro biomechanical properties of normal adult equine superficial digital flexor tendon (SDFT). Methods: Completely randomized design. Methods: Nine Standardbred horses, 6 to 9 years of age with ultrasonographically normal forelimb SDFT. Methods: Six horses were administered intramuscular (IM) rEGH at 10 microg/kg/day for 1 week, and then 20 microg/kg/day for another 5 weeks; 3 horses (control subjects) were administered an equivalent daily volume of sterile water IM. Horses were killed at the end of the 6-week treatm...
Dyson S, Murray R.Use of physiological methods of diagnostic imaging could provide insight into the pathogenesis of foot pain in live horses. Objective: To describe patterns and intensity of increased radiopharmaceutical uptake (IRU) in the navicular bone, and relate this to distribution and types of signal intensity change in the navicular bone and to the presence or absence of lesions of the related soft tissue structures detected using MRI. Methods: Scintigraphic and MR images of 264 horses with unilateral or bilateral foot pain were analysed and graded. A Spearman rank correlation was used to test for relat...
Nixon AJ, Sams AE, Ducharme NG.An endoscopically assisted technique for internally dividing the palmar or plantar annular ligament was developed in six cadaver limb specimens and two anesthetized horses. Under arthroscopic view, a slotted cannula was inserted into the digital sheath through a stab wound proximal to the annular ligament and advanced through the fetlock canal superficial to the flexor tendons with the slot oriented toward the fibers of the annular ligament. Division of the annular ligament by 90-degree tipped open and guarded blades was observed and verified by direct arthroscopic view. At necropsy, complete ...
Vanderperren K, Raes E, Bree HV, Saunders JH.This is the second part of a two-part review of the structures and disorders of the equine tarsus. In this part the bones of the tarsal region are considered and the technical aspects of taking radiographic, ultrasonographic and scintigraphic images of the different lesions are addressed. The diagnostic use of arthroscopy, computed tomography and magnetic resonance are discussed. In current clinical practice the most frequently used combination to arrive at a diagnosis is still radiography and ultrasonography.
Ellison ME, Duenwald-Kuehl S, Forrest LJ, Vanderby R, Brounts SH.To evaluate the feasibility and repeatability of in vivo measurement of stiffness gradients by means of acoustoelastography in the superficial digital flexor tendons (SDFTs) of clinically normal horses. Methods: 15 clinically normal horses. Methods: For each horse, stiffness gradient index and dispersion values for SDFTs in both forelimbs were evaluated in longitudinal orientation by use of acoustoelastography at 3 sites (5, 10, and 15 cm distal to the accessory carpal bone) by 2 observers; for each observer, data were acquired twice per site. The left forelimb was always scanned before the ri...
Kenny M, Cercone M, Rawlinson JJ, Ducharme NG, Bookbinder L, Thompson M, Cheetham J.Early detection of recurrent laryngeal neuropathy (RLN) is of considerable interest to the equine industry. Objective: To describe two imaging modalities, transoesophageal ultrasound (TEU) and computed tomography (CT) with multiplanar reconstruction to assess laryngeal muscle geometry, and determine the relationship between cricoarytenoid dorsalis (CAD) geometry and function. Methods: Two-phase study evaluating CAD geometry in experimental horses and horses with naturally occurring RLN. Methods: Equine CAD muscle volume was determined from CT scan sets using volumetric reconstruction with Live...
Jose-Cunilleras E, Hayes KA, Toribio RE, Mathes LE, Hinchcliff KW.To clone and sequence cDNA for equine insulin-responsive glucose transporter (glucose transporter type 4 [GLUT-4]) and determine effects of glycogen-depleting exercise and meal type after exercise on GLUT-4 gene expression in skeletal muscle of horses. Methods: Muscle biopsy specimens from 7 healthy adult horses. Methods: Total RNA was extracted from specimens, and GLUT-4 cDNA was synthesized and sequenced. Horses were exercised on 3 consecutive days. On the third day of exercise, for 8 hours after exercise, horses were either not fed, fed half of daily energy requirements as hay, or fed an is...
Lanyon LE.The skeleton consists of a series of elements with a variety of functions. In locations such as the skull, where shape or protection are of prime importance, the bone's architecture is achieved during growth under predominant genetic control. In locations such as the limbs, where the ability to withstand repetitive loading is important, only the general form of the bone will be achieved as a result of growth alone, the remaining characteristics resulting from an adaptive response to functional load bearing. In the horse, this functional load-bearing will be provided by the animal's natural act...
Maly IP, Eppler E, Müller-Gerbl M.Tissue-nonspecific alkaline phosphatase (TNAP) is playing a key role in bone calcification, as has been demonstrated in different mammalian species including human and rodents. However, to investigate age-related changes during life history, histochemical demonstration of TNAP is severely hampered, particularly in the elderly, by technical difficulties associated with sectioning calcified tissue. Sufficient fixation must precede decalcification since poorly fixed bone tissue is exposed to the deleterious effects of decalcification reagents. In order to find a method that would allow cryosectio...
Sellon DC, Knowles DP, Greiner EC, Long MT, Hines MT, Hochstatter T, Tibary A, Dame JB.Equine protozoal myeloencephalitis is a progressive neurologic disease of horses most commonly caused by infection with the apicomplexan parasite Sarcocystis neurona. Factors affecting neuroinvasion and neurovirulence have not been determined. We investigated the pathogenesis of infection with S. neurona in horses with severe combined immune deficiency (SCID). Two immunocompetent (IC) Arabian horses and two Arabian horses with SCID were infected orally with 5 x 10(5) sporocysts of S. neurona. Four IC horses and one SCID horse were infected intravenously (i.v.) with 5 x 10(8) merozoites of the ...
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...
Dyson S, Quiney L, Phillips K, Zheng S, Aleman M.Radiological observations at the cervicothoracic junction in horses with or without related clinical signs have not been comprehensively described. The aim was to evaluate the seventh cervical (C7) to second thoracic (T2) vertebrae in horses with neck-related clinical signs (neck pain and/or stiffness, neck-related forelimb lameness, or general proprioceptive [spinal] ataxia) and control horses. This prospective analytical cross-sectional study included 127 control horses and 96 cases, examined using standardized clinical and radiological protocols. Univariable logistic regression was used to ...
