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.
Becker CK, Savelberg HH, Buchner HH, Barneveld A.To evaluate clinical and biomechanical consequences of desmotomy of the accessory ligament (AL) of the deep digital flexor tendon (DDFT) of equine forelimbs and determine whether this procedure is a viable treatment for chronic desmitis of the AL-DDFT. Methods: 6 adult Standardbred trotters. Methods: Biomechanical recordings obtained before and 6 months after desmotomy were compared. Walk and trot joint angles, ground reaction forces, peak joint moments, and tendon forces were assessed. Results: Within 10 days after surgery, all horses were sound at a trot. Swelling, increased carpal flexion i...
Estberg L, Gardner IA, Stover SM, Johnson BJ.The objective of this study was to investigate the relationship between intensive racing and training schedules and risk of either catastrophic musculoskeletal injury (CMI) or lay-up from racing in California Thoroughbreds. Thoroughbred racehorses that sustained a CMI during racing or training and either were subsequently euthanized or died on a California racetrack during 1991 and 1992 were studied using a case-crossover study design. Each study subject (case) provided its own self-matched control information in the form of 'typical' exposure frequency, determined or estimated from historic i...
Reilly GC, Currey JD, Goodship AE.Exercise can have a profound effect on bone mass, but little is known of its effect on bone's material properties. In this experiment, our hypothesis was that a large difference in the training regimen of young thoroughbreds would produce a measurable difference in the mechanical properties of their bone material. When they were about 19 months old, eight thoroughbred racehorses were given one of two exercise regimens that lasted for 19 weeks: four horses (controls) were walked for 40 minutes a day but had no other exercise, and the remaining four (exercised) were additionally trotted for 20 m...
Pozio E, Celano GV, Sacchi L, Pavia C, Rossi P, Tamburrini A, Corona S, La Rosa G.Epidemiological investigations conducted during 10 trichinellosis outbreaks between 1975 and 1994 showed that horse-meat was the probable source of infection. Though hundreds of thousands of horses have been examined at abattoirs in America and Europe to detect Trichinella infection by artificial digestion or trichinelloscopy, an infected horse has never been detected during routine analysis, which consists of examining 1 g of tissue muscle from the diaphragm. In November 1996, a naturally infected horse imported from Romania was detected in Southern Italy. The parasite was identified as Trich...
Hopper SA, Schneider RK, Ratzlaff MH, White KK, Johnson CH.To determine the ability of a full-limb transfixation pin cast to protect the distal portion of the equine forelimb from weight-bearing forces by measuring bone strain in vitro on cadaver limbs loaded in a mechanical testing machine. Methods: 6 forelimbs from 6 horses. Methods: Each limb was instrumented with 3 unidirectional metal foil electrical resistant strain gauges. Gauges were placed on the dorsal aspect of the distal portion of the radius and the mid-dorsal portion of the cortex of the third metacarpal bone and the first phalanx. Each limb was tested 3 times, once supported with a tran...
Hopper SA, Schneider RK, Ratzlaff MH, White KK, Johnson CH.To determine the effect of pin hole size and number on the breaking strength of the adult equine radius when loaded in torsion to failure. Methods: 54 pairs of equine radii from adult horses. Methods: For test one, 12 pairs of radii were used to determine the effect of pin hole size on torsional breaking strength. A 6.35-mm hole was drilled in 1 radius, and a 9.5-mm hole was drilled in the contralateral radius. For test two, 36 pairs of radii were randomly assigned to 1 of 3 treatment groups (n = 12) to determine the effect of pin hole number on the torsional breaking strength of the equine ra...
Estberg L, Stover SM, Gardner IA, Johnson BJ, Jack RA, Case JT, Ardans A, Read DH, Anderson ML, Barr BC, Daft BM, Kinde H, Moore J, Stoltz J, Woods L.To investigate relationships of several racehorse characteristics and race conditions with risk of a catastrophic musculoskeletal injury (CMI) resulting in euthanasia in Thoroughbreds during racing in California in 1992. Methods: Retrospective longitudinal study. Methods: Thoroughbreds that incurred CMI during racing and all California race entrants in 1992. Methods: Necropsy records were reviewed, and race start information was obtained. Incidence risk of CMI/1,000 race entrants was estimated. Relationships between CMI during racing and race-meet, entrant age and sex, race type and length, an...
Gabriel A, Yousfi S, Detilleux J, Dessy-Doizé C, Bernard C.Navicular bones collected from the four limbs of 95 sound horses were studied. The anatomic bases have been laid down about morphometry of the navicular bones and their variations according to limbs, after corrections have been made for morphologic type, gender, weight, size and age. All the dimensions of the navicular bone (except for the thickness) were larger in the fore limb. This phenomenon probably reflects an attempt to compensate for the greater forces exerted upon the fore limbs during exercise and at rest. Navicular bones collected from the four limbs of 61 sound horses were studied ...
Wille KH, Zahner M.The vascular system of the large intestine of 12 horses was examined by means of vascular corrosion casts, histology and transmission electron microscopy providing the following results. The Aa. et Vv. breves et longae leave the mesenteric vessels, respectively the subserously on the teniae lying cecal vessels to reach the tela subserosa at the mesenteric margin. The short vessels enter the deeper layers of the wall instantly, whereas the Aa. et Vv. longae move towards the submucosa by penetrating the muscular layers after a variable subserous course. The tela submucosa contains an arterial an...
Zhang XY, Zhu FX, Olszewski MA, Robinson NE.The beta 2-agonists currently used as bronchodilators are racemic mixtures of R- and S-enantiomers. In the present study, we examined the effects of enantiomers of the beta 2-agonists albuterol and formoterol on acetylcholine (ACh) release from equine trachealis parasympathetic nerves. ACh release was evoked by electrical field stimulation (20 V, 0.5 ms, 0.5 Hz) and measured by high-performance liquid chromatography coupled with electrochemical detection. We also tested the effects of enantiomers of albuterol and formoterol on equine tracheal smooth muscle (TSM) contraction in response to exog...
Allen AL, Fretz PB, Card CE, Doige CE.A syndrome of congenital hypothyroidism and dysmaturity has been an important cause of reproductive loss and foal mortality in western Canada. The cause and pathogenesis of this syndrome is under investigation. One issue to be addressed is whether all the anomalies present in affected foals are produced concurrently by the same agent, or if affected foals are primarily hypothyroid in utero which induces the associated lesions. This study was designed to document the effects of fetal thyroidectomy, at about 215 days of gestation, on the growth and development of the equine fetus and to compare ...
Kawcak CE, Norrdin RW, Frisbie DD, Trotter GW, Mcilwraith CW.To determine the effects of osteochondral fragmentation and intra-articular corticosteroid treatment on dynamics of bone remodelling and fragility, 12 horses each had a unilateral, 8 mm osteochondral fragment created in the distal aspect of one radiocarpal bone. Six of the horses were treated in the fragmented joint, and the other 6 were treated in the nonfragmented joint with 12 mg of triamcinolone acetonide (TA) 14 and 28 days after surgery. All horses were exercised on a high-speed treadmill starting 15 days, and ending 72 days after surgery. Horses treated with TA in the fragmented joints ...
Patterson-Kane JC, Wilson AM, Firth EC, Parry DA, Goodship AE.Injury to the core of the mid-metacarpal region of the superficial digital flexor tendon in Thoroughbred racehorses is a very frequent but poorly understood condition. It has been suggested that subclinical changes induced by galloping exercise weaken the collagen in this region of the tendon, predisposing it to rupture. The longitudinally arranged collagen fibrils in tendon follow a planar waveform, termed the crimp. Fibril bundles with a smaller crimp angle fail at a lower level of strain than those with a larger crimp angle. This study tested the hypothesis that a specific 18 month exercise...
Skedros JG, Su SC, Bloebaum RD.Artiodactyl and perissodactyl calcanei have been recently introduced as models for examining bone for mechanically mediated adaptation. We have reported substantial regional variations in cortical bone microstructure and mineral content within the same cross-section of mule deer calcanei. In part, these variations may be adaptations accommodating the customary presence of predominantly tension, compression, and shear strain modes in mutually exclusive cortical locations. Calcanei from skeletally mature horses, elk, and sheep were examined in order to corroborate these previous findings. From e...
Pourcelot P, Audigié F, Degueurce C, Denoix JM, Geiger D.This study was conducted to evaluate a method for quantifying locomotion symmetry at trot in sound and lame horses. Using a 3D kinematic analysis system, the kinematics of the limb joints of sound and lame horses were recorded. The differences in motion between the left and right homologous joints were then quantified using a symmetry index based on an inter-correlation method. This method was used to calculate the symmetry indices of the vertical displacements and angle-time diagrams of the joints of each horse. In order to evaluate the sensitivity of this method of quantifying the locomotion...
Hyyppä S, Karvonen U, Räsänen LA, Persson SG, Pösö AR.To study the effects of nandrolone laureate (19-nortestosterone) on muscle hypertrophy and concentration of androgen receptors (AR), biopsy specimens were taken from the middle gluteal muscle of 6 Finnhorse trotters (geldings and mares) undergoing training before, immediately after, and 13 weeks after a 14-week treatment with nandrolone. Another 6 similarly trained horses served as controls. An additional 10 mares and 10 geldings were used to study annual variation in muscle concentration of AR. AR was immunohistochemically localized in the nuclei. AR concentration remained constant during the...
Rivero JL, Talmadge RJ, Edgerton VR.In adult horses, three myosin heavy chain (MyHC) isoforms can be identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunohistochemistry using specific anti-MyHC monoclonal antibodies. This report studies the suitability of a consistent SDS-PAGE technique for quantifying MyHC profiles in homogenized cryostate sections of equine gluteus medius muscle biopsies (n = 18). The method used (previously described by R. J. Talmadge and R. R. Roy; J. Appl. Physiol. 1993, 75, 2337-2340) resolved MyHCs in three bands: I, IIB or IIX, and IIA from the fastest to the slowe...
Ainsworth DM, Smith CA, Eicker SW, Ducharme NG, Henderson KS, Snedden K, Dempsey JA.In exercising quadrupeds, limb movement is often coupled with breathing frequency. This finding has lead some investigators to conclude that locomotory forces, associated with foot plant, abdominal visceral displacements or lumbo-sacral flexion, are the primary determinants of airflow generation. Analysis of respiratory muscle electrical activation (EMG) and contraction profiles in chronically instrumented dogs and horses, along with measurements of esophageal pressure (Pes) changes and limb movements, provide evidence that each breath during the exercise hyperpnea is determined by respiratory...
Cauvin ER, Munroe GA, Boyd JS.This study was undertaken to design a safe technique to examine the carpal flexor tendon sheath (carpal sheath) of horses endoscopically, using an arthroscope. The limbs from 15 horses were used to study the normal anatomy of the carpal sheath and related structures, establish a safe approach and endoscopic technique, and determine the normal endoscopic appearance of the sheath. Major arteries, veins and nerves, present within and around the sheath, left few 'safe' areas to insert the endoscope. Several portals were assessed and a distal lateral approach was found to be safest and to allow ade...
Cauvin ER, Munroe GA, Boswell J, Boyd JS.This study was undertaken to establish the gross anatomy and the ultrasonographic appearance of the carpal digital flexor tendon sheath (carpal sheath) and the palmar carpal region in normal horses. The isolated forelimbs from 15 horses were used to study the morphology of the sheath and associated structures, including a detailed study of the location of the main blood vessels and nerves in that region. These limbs and the forelimbs of five live, sound horses were also examined ultrasonographically. The examination yielded good soft tissue detail of the tendons and ligaments, synovial and per...
Williams TM, Dobson GP, Mathieu-Costello O, Morsbach D, Worley MB, Phillips JA.To establish a skeletal muscle profile for elite sprinters, we obtained muscle biopsy samples from the vastus lateralis, gastrocnemius and soleus of African cheetahs (Acinonyx jubatus). Muscle ultrastructure was characterized by the fiber type composition and mitochondrial volume density of each sample. Maximum enzyme activity, myoglobin content and mixed fiber metabolite content were used to assess the major biochemical pathways. The results demonstrate a preponderance of fast-twitch fibers in the locomotor muscles of cheetahs; 83% of the total number of fibers examined in the vastus laterali...
Keg PR, van Weeren PR, Back W, Barneveld A.The influence of the force applied and its period of application on the outcome of the flexion test of the distal forelimb was investigated in a group of eight sound horses. The degree of lameness after the flexion test was scored by a standard clinical classification, and by measuring the angle of maximum fetlock extension by means of the infrared light-based MacReflex gait analysis system. There was a good correlation between the clinical score and this electronically recorded kinematic parameter (r = 0.96). Both the force applied and the period of application affected the outcome of the tes...
Keg PR, van Weeren PR, Schamhardt HC, Barneveld A.A pressure-sensitive device was developed to measure the force applied to flexion tests of the distal limb of horses. The mean force applied by a group of experienced clinicians was 150 N which results in a moment on the flexed fetlock joint of about 28.5 Nm. The coefficient of variation of the force applied by one experienced clinician was only about 12 per cent, but the coefficient of variation between clinicians was considerably higher (20 per cent), irrespective of whether the clinicians were considered to be experienced or not. The mean force applied by a group of women examiners (114 N) ...
Bailey CJ, Reid SW, Hodgson DR, Suann CJ, Rose RJ.Risk factors for musculoskeletal injury in racing Thoroughbreds were investigated in a case-control study conducted at racetracks administered by the Australian Jockey Club. Univariable analysis of 137 cases from the official Veterinary Surgeon's reports and an equal number of randomly selected controls from the Australian Race Results identified field size, barrier position and class of race as being significantly associated with breakdown (P < 0.05). Multiple logistic regression was then used to investigate the effect of each putative risk factor whilst controlling for all others. Horses at ...
Sugiyama S, Fujiwara K.The angles related to the coxal joints were comparatively studied in four-limbed walking animals and two-limbed ones including man and birds. Between animals with both types of walking, no significant difference was observed in the neck-shaft angles (NSA), which was equivalent to the acetabulum angles (ACA) at the connection of the femoral head with the acetabulum. The anteversion angles (AVA) were equivalent to the horizontal ACA. Canine species showed two different forms of the femoral neck with or without modification by the femoral AVA, probably being breed-specific and nutrition-dependent...
Künzel W, Forstenpointner G, Skolek-Winnisch R.The laterocranial fascia of the upper arm and forearm, as well as aponeurotic relationships of the Musculus biceps brachii were investigated on each of ten forelimbs from horses, cattle and swine. Ten canine biceps were also investigated. Equine and bovine fascia contain elastic components. An as-yet undescribed ligament-like aponeuroses of the laterocranial forearm fascia to the Fossa radialis humeri was seen in all three species studied. The laterocranial fascia of the upper and forearm form a common passage for the Musculi brachialis et extensor carpi radialis. In the case of the horse, the...
Thompson KN, Baker JP, Jackson SG.Thirty foals of mixed breeding, from two consecutive years, were used in two 120-d experiments to evaluate the effects of supplemental feeding (creep feed) on growth in nursing foals. At 10 d postpartum, foals were randomly assigned either to a creep-fed group (CF) or an unsupplemented group (NCF). Initial measurements of body weight (BW), height at the withers (WH), third metatarsal length (MtIII) and third metacarpal length (McIII) were made at 10 d of age and at 30-d intervals thereafter. Medial and lateral cortical peak values for radiographic bone density, cortical width and cortical area...
Barker WH, Wright IM.Accurate description of the calcaneal insertions of the superficial digital flexor tendon (SDFT) is lacking and inconsistent. The aim of this study was to undertake morphologic and morphometic evaluations of these structures to assist in elucidating their functional and pathogenic roles in displacement of the SDFT from the calcaneal tuber. Methods: Dissections were performed on 10 normal cadaveric hindlimbs. The anatomy was photographed to allow measurements at repeatable locations and differences in SDFT dimensions at the various locations were compared using a paired student t-test. Results:...
Chalmers HJ, Viel L, Caswell JL, Ducharme N.To describe the ultrasonographic changes in the cricoarytenoideus dorsalis (CAD) and cricoarytenoideus lateralis (CAL) muscles of horses before and at various times during the 32 weeks after unilateral neurectomy of the right recurrent laryngeal nerve. Methods: 28 healthy Standardbreds. Methods: For each horse, the appearance of the CAD and CAL muscles on the right (neurectomized) and left (control) sides was serially monitored ultrasonographically by percutaneous (CAD and CAL) and transesophageal (CAD) approaches. The ultrasonographic images were assessed to determine the mean pixel intensity...
Carstanjen B, Lepage OM, Hars O, Langlois P, Duboeuf F, Amory H.The purpose of this longitudinal in-field study was to evaluate the influence of exercise, age, and gender on superficial cortical bone of the third metacarpal bone (MC III) in young Thoroughbreds by measuring speed of sound (SOS) values with an axial transmission technique (Omnisense, Sunlight Ltd, Israel). Both MC III of 75 racehorses, 2 to 4 years old, were monitored with SOS measurements in 5- to 7-week intervals during a 9- month physical exercise period. Medical data and training programs (slow gallop, canter, and high-speed work) of each horse were recorded. SOS measurements began befor...
Hildebrand SV, Howitt GA, Arpin D.Atracurium besylate, a recently developed, intermediate-duration acting, neuromuscular-blocking agent, was given to 15 halothane-anesthetized ponies to produce surgical relaxation (95% to 99% reduction of hoof twitch). All 15 ponies were given 3 injections; 8 of the 15 ponies were given 2 additional injections. Initial dosage of 0.11 +/- 0.01 mg/kg (mean +/- SD) and all subsequent injections of 0.052 mg/kg produced desired relaxation. Paralysis phase (maximum twitch reduction to 10% twitch recovery) lasted 24 +/- 5 minutes for the initial injection. Paralysis from subsequent injections lasted ...
Lescun TB, Adams SB, Main RP, Nauman EA, Breur GJ. The objectives of this study were to validate a finite element model of the equine distal limb transfixation cast and to determine the effect of six transcortical pin parameters on bone-pin interface (BPI) stresses in the third metacarpal bone. Methods: A transfixation cast finite element model was developed from a computed tomography scan of the third metacarpal bone and modelled pin elements. The model was validated by comparing strain measured around a 6.3-mm transfixation pin in the third metacarpal bone with the finite element model. The pin parameters of diameter, number, location,...
Lloyd DR, Rose RJ.Sodium bicarbonate given by nasogastric tube has been used by some trainers as the key ingredient in a 'milkshake'. It has been suggested that such treatment given 3-5 h prior to racing may enhance a horse's racing performance by increasing the blood buffering capacity and enhancing lactate clearance from skeletal muscle, thereby delaying the onset of fatigue. Several experiments were conducted to examine the effects on fluid, electrolyte and acid-base values of 0.5 g kg-1 dose of sodium bicarbonate, were examined. The effects of fasting, the simultaneous administration of glucose (0.5 g kg-1)...
Noguera Cender A, Mählman K, Lischer CJ.To describe and evaluate an alternative technique for tenoscopic resection of the manica flexoria (MF). Methods: Descriptive study. Methods: Equine cadaver forelimbs and hind limbs (n = 36). Methods: Three surgeons varying in experience resected the MF in 12 limbs. The procedure was divided into six steps, including resection of the lateral/medial borders of the MF with a hook knife and resection of the proximal border with a micro scalpel. Outcomes compared between surgeons included completeness of resection, appearance of the margins of resection, appearance of the resected MF, collateral da...
Eto D, Yamano S, Kasashima Y, Sugiura T, Nasu T, Tokuriki M, Miyata H.Most racehorses are trained regularly from about age 18 months; therefore, little information is available on the effect of training in Thoroughbred foals. Objective: Well-controlled exercise could improve muscle potential ability for endurance running. Methods: Thoroughbred foals at age 2 months were separated into control and training (treadmill exercise) groups and samples obtained from the middle gluteal muscle at 2 and 12 months post partum. Muscle fibre compositions were determined by histochemical and electrophoretical techniques and succinic dehydrogenase (SDH) activity was analysed in...
Ząbek T, Witarski W, Szmatoła T, Sawicki S, Mrozowicz J, Samiec M.Epigenetic mechanisms of gene regulation are important for the proper differentiation of cells used for therapeutic and regenerative purposes. The primary goal of the present study was to investigate the impacts of 5-aza-2' deoxycytidine (5-AZA-dc)- and/or trichostatin A (TSA)-mediated approaches applied to epigenomically modulate the ex vivo expanded equine chondrocytes maintained in monolayer culture on the status of chondrogenic cytodifferentiation at the transcriptome level. The results of next-generation sequencing of 3' mRNA-seq libraries on stimulated and unstimulated chondrocytes of th...
Merritt JS, Davies HM.Bending of the equine metacarpal bones during locomotion is poorly understood. Cantilever bending, in particular, may influence the loading of the metacarpal bones and surrounding structures in unique ways. Objective: We hypothesised that increased amounts of sagittal-plane cantilever bending may govern changes to the shape of the metacarpal bones of Thoroughbred racehorses during training. We hypothesised that this type of bending would require a linear change to occur in the combined second moment of area of the bones for sagittal-plane bending (I) during race training. Methods: Six Thorough...
Back W, van den Bogert AJ, van Weeren PR, Bruin G, Barneveld A.To get an in-depth insight into the ontogeny of the equine locomotor apparatus, the locomotion of 28 Dutch Warmblood foals was recorded at the walk, trot and canter on a treadmill using a CODA-3 apparatus. A great similarity in joint angle-time diagrams was found, although considerable differences in kinematic gait parameters of individual foals could be detected. These results contribute to an objective comparison of the locomotor performance of foals.
White NA, Wheat JD.Proximal tibial epiphyseal fractures in 2 foals were reduced and stabilized by expansion and compression between 2 transversely placed Steinman pins, one on each side of the fracture. A Charnley apparatus or turnbuckles placed between the pins on each side of the fracture provided the mechanical advantage for repositioning the fracture fragments and achieving rigid fixation during healing. A light cast was applied over the fixation apparatus, keeping the limb in an extended position. The cast and fixation apparatus were removed after 4 weeks. The technique allowed rapid healing and adequate am...
Salem M, El-Shafaey ES, Farag AMM, El-Khodery S, Al Mohamad Z, Abass M.This study was conducted to establish a detailed anatomic reference for the carpal joint of apparently healthy donkeys using ultrasonography (US), computed tomographic (CT), and magnetic resonance imaging (MRI). Ten orthopedically sound adult donkeys were used for US examination of the carpal joint in each forelimb. Additionally, the carpi of ten donkey cadavers were subjected to CT and MRI examinations. The carpal joint was divided into four zones to simplify examination. US assessment of the carpal joint included transverse and longitudinal sonograms. CT was performed using three planes: axi...
Nocera I, Aliboni B, Ben David L, Gracia-Calvo LA, Sgorbini M, Citi S. Laminitis is a debilitating disorder resulting in irreversible anatomical changes in the feet of equids. Assessing specific anatomical features through radiography and venography provides diagnostic and prognostic information. The reference ranges are well-established in horses, but not in donkeys. It is also uncertain as to whether these ranges can be applied to every donkey breed. The present study characterizes the radiological and venographic hoof anatomy of healthy feet of Amiata donkeys and defines the changes associated with severe and mild laminitis. A total of 16 forefeet were evalu...
Horstmeier C, Ahrberg AB, Berner D, Burk J, Gittel C, Hillmann A, Offhaus J, Brehm W.The magic angle effect increases the MRI signal of healthy tendon tissue and could be used for more detailed evaluation of tendon structure. Furthermore, it could support the discrimination of hypointense artefacts induced by contrast agents such as superparamagnetic iron oxide used for cell tracking. However, magic angle MRI of the equine superficial digital flexor tendon has not been accomplished in vivo in standing low-field MRI so far. The aim of this in vivo study was to evaluate the practicability of this magic angle technique and its benefit for tracking superparamagnetic iron oxide-lab...
Takeyama T, Sasaki N.Thoracic spinous process osseous changes in horses occur due to riding-induced back compression. This study aimed to evaluate the relationship between the findings of thoracic spinous process osseous changes on radiographic imaging and conformation based on the difference in over-riding of the dorsal spinous processes in racing horses. This study included 55 sports horses. The hardness of the back muscles (the multifidus, longissimi, and latissimi collectively) was measured, and the horses were divided into two groups: low muscle hardness (n = 16) and high muscle hardness (n = 39). We conf...
Dyson S, Murray R, Branch M, Whitton C, Donovan T, Harding E.Sacroiliac (SI) disease is recognised as a cause of poor hindlimb action but differential diagnosis is often difficult. Objective: That in clinically normal horses there would be a significant difference in the ratio of radiopharmaceutical uptake (RU) between the fifth lumbar vertebra (L5) and each tuber sacrale (TS) and between L5 and each SI joint; and that these ratios would alter with age, but ratios would be bilaterally symmetrical. Methods: Dorsal scintigraphic images of the SI region of 15 horses, selected randomly from the clinic database, were analysed by 2 of the authors, comparing n...
Bio SystemsFebruary 27, 2023
Volume 225 104871 doi: 10.1016/j.biosystems.2023.104871
Bhattacharjee S.Adaptations in equine limbs, including fusion of its bones, such as the metapodials II and IV (splint bones) with metapodial III (cannon bone), have been debated. It is argued that cursorial adaptations in equine limbs with a progressive reduction in the number of digits lighten up the limbs and facilitate fast running. Similar fusions in other bones, such as the radius and ulna, tend to exhibit similar traits. For example, the fusion often occurs in a disto-proximal direction while leaving sharp ridges. This article proposes a model to understand the biomechanical advantages that a fused symm...
Cheetham J, Regner A, Jarvis JC, Priest D, Sanders I, Soderholm LV, Mitchell LM, Ducharme NG.Bilateral vocal fold paralysis (BVCP) is a life threatening condition and appears to be a good candidate for therapy using functional electrical stimulation (FES). Developing a working FES system has been technically difficult due to the inaccessible location and small size of the sole arytenoid abductor, the posterior cricoarytenoid (PCA) muscle. A naturally-occurring disease in horses shares many functional and etiological features with BVCP. In this study, the feasibility of FES for equine vocal fold paralysis was explored by testing arytenoid abduction evoked by electrical stimulation of t...
Semevolos SA, Watkins JP, Auer JA.To describe surgical arthrodesis of the scapulohumeral joint and to evaluate its efficacy in reducing morbidity associated with severe shoulder dysfunction in miniature horses. Methods: Retrospective study. Methods: Four miniature horses. Methods: Medical records and radiographs were reviewed for history, physical examination findings, lameness evaluation, radiographic evaluation, surgical techniques, postoperative complications, and outcome. A 10- or 11-hole, 4.5-mm narrow dynamic compression plate and 4.5-mm cortical screws were applied to the cranial surface of the scapula and cranial surfa...
Leach DH, Zoerb GC.The mechanical properties of pigmented equine hoof wall tissue were determined for samples taken from the inner and outer portions of the stratum medium of the toe. Two properties, the modulus of elasticity and proportional limit, which are measures of the rigidity and yield point, respectively, of the tissue, were studied for samples compressed in 3 orthogonal directions. All samples tested were anisotropic. Inner wall samples were less rigid and had a lower yield point than outer wall samples.
Art T, Lekeux P.In order to study the in vitro mechanical properties of the equine trachea submitted to the compressive pressures observed in vivo, the pressure-volume relationship was determined in intra- and extra-thoracic tracheal segments taken post mortem from 29 healthy horses (one to 15 years old; 352 to 651 kg). At the same time, the cross-sectional lumen area (X-SA) at the mid-point of the segment was measured using a slit-lamp transillumination and photographic measurement by endoscopy. The tracheal specific compliance (Cs) as well as the relative changes in X-SA and in the sagittal and transverse d...
Valentine BA, Hammock PD, Lemiski D, Hughes FE, Gerstner L, Bird KE.Severe diaphragmatic necrosis occurred in horses with degenerative myopathy due to polysaccharide storage myopathy (n = 2), nutritional myopathy (n = 1), and vasculitis (n = 1). Blood gas analysis performed in 1 horse indicated development of respiratory acidosis. Respiratory muscle necrosis can be severe in horses with degenerative myopathy and can lead to respiratory failure.
Ehrle A, Lilge S, Clegg PD, Maddox TW.Flexor tendon injuries are a common cause of lameness and early retirement in equine athletes. While ultrasonography is most frequently utilised, advanced diagnostic imaging modalities are becoming more widely available for detection and monitoring of flexor tendon lesions. Part two of this literature review details current experience with low- and high-field magnetic resonance imaging (MRI) and computed tomography (CT) for the diagnosis of equine flexor tendinopathy with a focus on the deep digital flexor tendon. Implications of the 'magic angle' artefact as well as injection techniques and t...
Mudge MC, Bramlage LR.Emergency management of distal limb and skull fractures in horses is vital to the successful outcome of these cases. Distal limb fractures, in particular, require careful assessment and counseling of the owner as well as adequate stabilization or coaptation of the fracture. Horses with limb or skull fractures may also have concurrent pain, blood loss, and other fluid losses that can result in shock requiring fluid therapy before definitive treatment of the fracture. Proper emergency fracture stabilization, initial treatment in the field, and patient transport are discussed.
McClure SR, Watkins JP, Ashman RB.Breaking strength (torque at failure) of equine third metacarpal bones, with transfixation pins placed parallel in the frontal plane and 30 degrees divergent from the frontal plane, was determined in vitro. Two transfixation pins were placed through the distal metaphysis, using a jig designed to drill the holes in the assigned configuration. Paired metacarpal bones II through IV from 12 horses were tested in torsion. The torsional moment of the force applied through the transfixation pins at failure was compared for each limb. Metacarpal bones with divergent pins were significantly (P = 0.030)...
Brock BA, Greer HR, Honnas CM, Gilleland BE, Barrett MF, Moore JN, Cohen ND.Podotrochlear syndrome is a common cause of lameness in Quarter Horses involving both soft tissue and bony structures within the heel region. Current surgical treatment of podotrochlear syndrome addresses pathological changes affecting the soft tissue structures of the navicular region but does not address either edema or cyst-like lesions of the navicular bone. Unassigned: The objective of this randomized, self-controlled case series was to determine whether core osteostixis improved lameness in Quarter Horses with podotrochlear syndrome characterized by bilateral magnetic resonance imaging (...
Ranner W, Schill W, Gerhards H.The radiological examination of the thoracolumbar spine of a horse with a potential back problem is most important in order to come to a diagnosis and the imaging method of choice. The use of parallel grid-cassettes, appropriate films, rare earth screens and aluminium filters requires radiographic equipment with an output of 60-120 kV and 25-90 mAs. By use of this technique in the standing horse it is possible to obtain radiographs of the summits of the dorsal spinal processes of the thoracolumbar spine from the first thoracic (T1) to approximately the third of fourth lumbar vertebrae (L3/4). ...
