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.
Gunson DE, Rooney JR.An 8-year-old gelding with a long-standing, streptococcal respiratory infection developed dyspnoea and colic. Laparotomy disclosed numerous, discrete, hemorrhagic, thick areas of necrosis throughout the intestinal tract. At postmortem examination similar lesions were seen in the laryngeal mucosa and in many skeletal muscles. Microscopically these lesions had massive necrosis and hemorrhage with a leucocytoclastic vasculitis in adjacent tissue. This condition resembled anaphylactoid purpura (Henoch-Schönlein disease) in man. Fungal infection was ruled out by special stains which failed to show...
Guy PS, Snow DH.1. Percutaneous needle biopsies were obtained from six limb muscles in six horses before and during a training programme of 10 or 15 weeks designed to involve both aerobic and anaerobic work. In a subsequent detraining period, biopsies were also taken after 5 and 10 weeks. 2. Samples were analysed biochemically for enzyme activity of lactic dehydrogenase (LDH), creatine phosphokinase (CPK), aldolase (ALD), citrate synthase (CS), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) and for glycogen content. Fibre typing was carried out histochemically before and 10 weeks after c...
Campbell JR.Limb angulation in foals may be due to defects in epiphyseal growth plates. The present state of knowledge concerning rate of growth in foals and differences in growth of different epiphyseal plates is reviewed and the importance of accurate knowledge of these parameters in treatment of angulation by unilateral retardation of an epiphyseal growth plate is stressed. Retardation of epiphyseal plate growth by compression wiring is described and its advantages in comparison with staplings are suggested. Compression wiring was used in 3 cases in which age, bone width and the degree of angulation we...
Frost GE, du Preez HR.A 3 year old thoroughbred colt in full training pulled up
acutely lame during a training gallop on a dirt track.
According to the trainer no reason for the injury was
evident. The horse refused to bear weight on the leg
and when forced to walk back to the stables it would
only touch the affected toe to the ground. The fetlock
soon became swollen and was very painful. The trainer
treated the animal for a sprain with ice packs and
bandages. No improvement occurred in 72 hours and
veterinary advice was sought.
Examination revealed the horse to be in obvious
pain. He was unable to bear ...
Shively JA, Van Sickle DC.The scanning electron microscopy of synovial membrane from the radiocarpal and intercarpal joints near the lateral and medial borders of the tendon of the extensor carpi radialis muscle was studied in 5 ponies. Three different morphologic types of synovial membrane were observed. Type 1 synovial membrane was folded and had a surface mat of fibers separated by 1- to 5-micron-diameter holes. The 2nd and 3rd types of synovial membrane were both villous. The surface of type 2 synovial membrane was fibrillar but the surface of type 3 synovial membrane was cellular. The type of synovial membrane pre...
Adrian M, Grant B, Ratzlaff M, Ray J, Boulton C.Electrogoniometry was used qualitively and quantitatively to assess the movements of the normal and pathologic metacarpophalangeal joints of selected horses. A total of 4 Thoroughbreds, 1 normal and 3 with clinical and radiographic changes in the metacarpophalangeal joints of 1 limb, were evaluated at the walk and trot. Goniograms of the affected joints were compared with those of the normal horse and the normal contralateral metacarpophangeal joint. Qualitative asymmetry was recognized on the goniograms, and the ranges of motion were quantified and related to the clinical and radiologic obser...
Webbon PM.The results of a survey are presented in which 589 limbs from 206 horses were dissected. In174 of the limbs lesions were found in either the superficial (131) or deep (43) digital flexor tendons. Changes occurring with age were also recorded. The sites of the abnormalities and their macroscopical appearance are described and the value of the results is considered in relation to the diagnosis and the treatment of clinical lesions.
Knight AP.Dysphagia developed in a 2-year-old Quarter Horse filly following an incident in which it fell over backward while exercising on a mechanical horse walker. Hyperextension of the neck at this time apparently caused unilateral rupture of the longus capitis (rectus capitis ventralis major) and the rectus capitis ventralis minor muscles at their insertion. An existing mycotic lesion involving the dorsomedial wall of the left guttural pouch may have weakened the area of insertion of the involved muscles. Tearing of the tendinous insertion of these muscles caused damage to the IX, X, and XI cranial ...
Rose RJ.Complications from neurectomy have been well known for many years. A 16-year-old mare suffered bilateral luxation of the coffin joints following palmar neurectomy and was destroyed. Autopsy showed complete rupture of the deep flexor tendons, and the supporting ligaments of the coffin joints. Arthritis of the coffin joints, with erosion of articular cartilage was evident.
Moore JN, Mcilwraith CW.Two cases of osteochondrosis are presented. Lesions involving the lateral trochlear ridge of the femur are demonstrated on conventional radiographs and double-contrast arthrograms. A radiographic suggestion of osteochondrosis lesions in the patella is noted. Post mortem examination of one case confirmed the presence of partially free cartilaginous flaps. Reference is made to familial tendency to osteochondrosis in man, dog, pig and horse. The significance of rapid growth rate in the pathogenesis of the condition is also discussed.
Jones RD, Fessler JF.ALTHOUGH METACARPAL TI-IV and metatarsal II-IV (MC II-IV, MT II-IV) fractures are frequent in horses and surgical intervention routine, a review of the current literature revealed little information about this subject. The authors have found only two complete accounts of this problem (1, 6). The incidence of suspensory desmitis has been previously reported (3), but we find no previous correla-tion of MC II-IV, MT II-IV fractures with suspensory, desmitis. On these bases, a re-trospective study was conducted. At Purdue University from 1967 through 1974, 50 Standardbred horses underwent sur-gery...
Gabel AA, Spencer CP, Pipers FS.The distal radial physes of 113 two-year-old Standardbreds were radiographed an average of 2.6 times each during an average of 4.72 +/- 1.7 months, beginning May 1, 1975. The radiograph of each physis was graded C, B-, B, B+, or A (closed), and the date of closure was determined by a method that proved to be reliable. The average age of closure of the distal radial physes was 29.8 +/- 1.6 months, with age of closure ranging from 26 to 35 months. There were no statistical differences between age of physeal closure of colts, geldings, or fillies; pacers or trotters; "well-bred" or other horses, ...
Gideon L.A discussion of the merits of acupuncture therapy and a review of experiments that support the neurogenic mediation of acupuncture are presented. Case reports are included as examples of the therapeutic value of acupuncture in treatment of intestinal and musculoskeletal disorders in the horse. Statistical importance cannot be credited to the clinical experiences reported here because of the small number of cases. Hopefully, the clinical success reported will encourage continued investigation of the clinical efficacy and adjunctive value of acupuncture in the veterinary profession.
Pratt GW, O'Connor JT.The force plate can measure a wide range of effects in the horse. The same instrument can record forces from more than a ton in the galloping animal to 25 g associated with the action of the heart. In all probability, the force plate will develop into a valuable clinical instrument.
Boyd JS.The deformities observed in 2 Clydesdale foals are described. Both had abnormal joint positions in the forelimbs and discrepancies in the symmetry of the vertebral column. The changes were only mild in one case but extreme in the other where it was accompanied by torticollis, scoliosis and vertebral fusion. A comparison is made with deformities described in the contracted foal syndrome and some of the developmental implications discussed.
Snow DH, Guy PS.The use of the technique of percutaneous needle biopsy in obtaining skeletal muscle samples in the horse is described. The biochemical, ultrastructural and histochemical investigations that can be carried out on this biopsy specimen are outlined. Analyses performed on the specimen may be used to obtain information on racing potential and state of fitness. These studies on normal horses will provide information for future investigations into the structural and biochemical alterations in muscle disorders in the equine.
Rankin JS, Diesem CD.The hindlimbs of 3 ponies and 3 horses were dissected. The hip joint capsule was found to receive articular nerve fibers from the femoral, obturator, cranial gluteal, and sciatic nerves. The nerve fibers were distributed to the fibrous joint capsule and associated capsular ligaments. The stifle joint capsule was found to receive articular branches from the femoral, saphenous, obturator, common peroneal, and tibial nerves. The fibers terminated in the joint capsule, fat pad, patellar and collateral ligaments, and the internally situated meniscal and cruciate ligaments.
Bailey J, Redpath A, Hallowell G, Bowen M.The clinical examination of lame horses in real world settings often requires the use of sloped surfaces. This pilot study aimed to evaluate the effects of uphill and downhill locomotion on asymmetry in horses with naturally occurring lameness affecting forelimbs and hindlimbs. Ten horses (8-19 years) with forelimb lameness and eight horses (7-16 years) with hindlimb lameness were fitted with inertial sensors at the poll, withers, sacrum and both tuber coxae. Data were collected whilst the horses were trotted in hand on a level surface (20 mm) among conditions in individual horses. Two horse...
Bain FT, Merritt AM.To investigate the possibility that a disorder of potassium balance may have a role in the development of equine rhabdomyolysis, the potassium concentration within erythrocytes (RBC [K+]) and plasma (P [K+]) was measured in 3 groups of horses: group 1, eight 2-year-old fillies that had postexercise muscle soreness within 48 hours of sample collection; group 2, ten 2-year-old fillies subjected to identical management and training conditions (as fillies of group 1) and that did not have signs of myopathy; and group 3, 32 yearlings of both sexes on the farm of origin of groups 1 and 2 that were p...
Sato F, Endo Y, Horiuchi N, Tominari M, Murase H, Ishimaru M, Korosue K.Although radiographic findings at the apical portion of the proximal sesamoid bone (PSB) are often observed in young Thoroughbred foals, conflicting findings, either fractures or apparent secondary ossifications centers, have been reported. Three cases (aged 2, 5, and 7 weeks) were identified in 30 necropsied foals (0-31 weeks old). Histopathologically, the subchondral trabecular woven bone was fractured and exhibited focal necrosis of woven bone, fibrin exudate, and/or fibrosis within the foci. In the 7-week-old case, proliferations of chondrocytes were also observed. These findings suggest t...
Mountford D.VetCell Bioscience is a UK-based company focused on pioneering the use of regenerative medicine in the animal health market. VetCell was formed in partnership with the Royal Veterinary College and the Institute for Orthopaedic and Musculoskeletal Science to develop the use of cellular therapies to treat athletic injuries in horses. This ground-breaking work has been the springboard from which the Company has expanded into other areas of veterinary regenerative medicine.
Bertone AL, McIlwraith CW, Powers BE, Stashak TS, Aanes WA, Turner AS.Subchondral osseous cystic lesion of the elbow was diagnosed as a cause of lameness in 6 horses. Persistent lameness and signs of degenerative joint disease developed in the first 3 horses treated conservatively with confinement. Subsequently, 3 horses were each treated by extra-articular enucleation of the cystic cavity via the proximal-medial aspect of the radius. Compared with conservative management, better long-term success (determined by return of athletic soundness and less evidence of degenerative joint disease) was achieved with surgical curettage of elbow subchondral cystic lesions.
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...
Beech J, Fletcher JE, Erwin K, Lindborg SR.To determine sensitivity of equine skeletal muscle to tetrodotoxin and compare that with sensitivity of murine and human skeletal muscles. Methods: Semimembranosus, vastus lateralis, triceps brachii, and masseter muscle specimens from 22 euthanatized horses, vastus lateralis muscle biopsy specimens from 25 clinically normal humans, and diaphragmatic muscle specimens from 6 mice. Methods: Electrically elicited twitch responses were measured in muscle specimens incubated in medium alone and with tetrodotoxin (100 nM, 400 nM, 1.6 microM for equine specimens and 100 nM, 200 nM, 400 nM, 800 nM, 1.6...
Ott EA, Brown MP, Roberts GD, Kivipelto J.Forty-four weanling horses were used in two experiments to evaluate the effect of starch intake on growth and skeletal development. In Exp. 1, the weanlings were fed either a grain-based, high-starch (31.1%, DM basis) concentrate or a by-product-based, low-starch (0.0%) concentrate with coastal bermudagrass (Cynodon dactylon) hay. Corn oil was used to equalize the energy concentration of the concentrates. The concentrate:hay ratio was 64:36 (as-fed basis), and intake was the same for both diets. Body weight gains were greater by the weanlings consuming the high-starch concentrate (0.81 vs. 0.6...
Landry Z, Roloson MJ, Fraser D.The metapodials of extinct horses have long been regarded as one of the most useful skeletal elements to determine taxonomic identity. However, recent research on both extant and extinct horses has revealed the possibility for plasticity in metapodial morphology, leading to notable variability within taxa. This calls into question the reliability of metapodials in species identification, particularly for species identified from fragmentary remains. Here, we use ten measurements of metapodials from 203 specimens of four Pleistocene horse species from eastern Beringia to test whether there are s...
van Grevenhof EM, Gezelle Meerburg ARD, van Dierendonck MC, van den Belt AJM, van Schaik B, Meeus P, Back W.Osteochondrosis (OC) is a common, clinically important joint disorder in which endochondral ossification is focally disturbed. Reduced blood supply to growing cartilage is considered an important cause of the condition, which has both genetic and environmental origins. Housing conditions can influence cartilage injury through peak-pressure changes during limb sliding. Additionally, circulatory perturbation can cause the avascular necrosis of cartilage. In this study, we evaluated the type and frequency of limb sliding during standing up and the occurrence of OC in foals aged up to 12 months o...
Strashko EY, Kapustianska АA, Bobyreva LE.Matters of physical and medical rehabilitation of children with organic lesions of the nervous system, in particular, with cerebral palsy, are actual in countries around the world. Hippotherapy is neurophysiologically oriented therapy using horses. Determine whether a combination of hippotherapy as a method of rehabilitation in the aftermath of outpatient comprehensive impact on MS on a stationary phase; Study of the effect of hippotherapy as securing and preparation method for learning new postures and movements in children with spastic cerebral palsy forms; The study of the possible optimiza...
Harfoush K, Guintard C, Desfontis JC, Thorin C, Douart C, Mallem MY, Betti E.Dysfunction of venous valves can lead to hemodynamic disorders causing venous stasis, which would favour the occurrence of equine laminitis. However, very few studies have investigated venous valves in the horse digit. The purpose of this study was to compare valvular density between thoracic and pelvic limbs and to study the relationship between valvular density of veins and their location, diameter and wall thickness. After dissection, valvular density was calculated based on the number of valves counted in the principal veins of 7 thoracic and 7 pelvic limbs from 7 horses. Our results showe...
Bombardi C, Grandis A, Gardini A, Sorteni C, Clavenzani P, Chiocchetti R.The activity of the gastrointestinal tract is regulated through the activation of adrenergic receptors (ARs). Since data concerning the distribution of ARs in the horse intestine is virtually absent, we investigated the distribution of β2-AR in the horse ileum using double-immunofluorescence. The β2-AR-immunoreactivity (IR) was observed in most (95%) neurons located in submucosal plexus (SMP) and in few (8%) neurons of the myenteric plexus (MP). Tyrosine hydroxylase (TH)-IR fibers were observed close to neurons expressing β2-AR-IR. Since β2-AR is virtually expressed in most neurons located...
Zuffa T, Bennet ED, Parkin TDH.Endurance riding is a popular equestrian sport organised at the international level by the Fédération Équestre Internationale (FEI). The sport involves prolonged exercise at speed over significant distances, which puts a substantial load on equine athletes' musculoskeletal systems and metabolism and contributes to the risk of injuries and other veterinary problems. The FEI employs a system of in-ride veterinary inspections aimed at early detection of such problems and elimination of horses unfit to continue in the ride. To date, risk factors for elimination due to irregular gait or metaboli...
Gaughan EM.Skeletal origins of exercise intolerance and performance failure can reside in multiple tissues. Diagnosis of injury that results in an ability to continue to exercise, yet inefficiently do so, requires familiarity with evaluation of subtle lameness and often with the specific demands of the different equine sports. Imaging is usually vital to diagnosis development and understanding of lesion influences on locomotion. Therapy is lesion dependent. Return to competitive exercise and performance is dictated by an understanding of skeletal tissue response to injury, rational progressive treatment,...
Kneller SK, Losonsky JM.Bilateral metacarpophalangeal radiographs of 100 Thoroughbreds were examined for visualization and location of the major nutrient foramen of the proximal phalanx. The foramina were located on the dorsal or palmar aspects of the cortex or were not visible radiographically. Of the 100 horses, 60 had the same pattern in both forefeet. In the remaining 40 horses, the left and right proximal phalangeal foramina were asymmetric. Of the 200 proximal phalangeal foramina (100 horses), 53 were on the dorsal aspect of the cortex and 101 were on the palmar aspect of the cortex; 46 were not visible radiogr...
Bindler D, Koch C, Gendron K, Ferguson SJ, Kaposi AD, Papp M, Bodó G.Mechanical evaluation of a novel screw position used for repair in a type III distal phalanx fracture model and assessment of solar canal penetration (SCP). Methods: Experimental study. Methods: Disarticulated equine hooves (n = 24) and 24 isolated distal phalanges. Methods: Hooves/distal phalanges cut in a sagittal plane were repaired with 1 of 2 different cortical screw placements in lag fashion. In group 1 (conventional screw placement), the screw was inserted halfway between the proximal border of the solar canal (SC) and the subchondral bone surface on a line parallel to the dorsal co...
Bernath CM, Valet S, Rossignol F, Weisse B, Fürst AE, Kümmerle JM. The aim of this study was to evaluate the effect of reducing the bone to cast distance on the resistance of the pin to cyclic loading in equine transfixation pin casts. Methods: Eleven pairs of cadaveric equine third metacarpal bones were prepared and one 6.3/8.0 mm transfixation pin was placed in standard fashion 10 mm proximal to the distal physeal scar into each bone. One metacarpus of each pair was tested with a distance of 10 mm (10 mm group) and the contralateral metacarpus with a distance of 20 mm (20 mm group) between the outer cortex of the bone and the fixation of t...
Frewein J, Buff E.In the anatomical literature there are inconsistencies in the description of the levatores costarum muscles in man and in the domestic animals, and their innervation either by the dorsal or the ventral branches of the thoracic nerves. Therefore we studied the form, structure and, with the aid of the dissecting microscope, the innervation of these muscles in 7 dogs, 8 cats, 5 horses and 12 pigs. In the dog, cat and horse, mm. levatores costarum are present from the second to the last rib. In the pig, these muscles are present from the second to the 15th rib, even in individuals with 16 pairs of...
Rothhaupt D, Ziegler H, Laser T.The orthopedic hippotherapy represents a new form of therapeutic exercise in the conservative treatment of segmental instabilities in the lumbar spine region. This kind of therapy works on the principle of conveying to the patient the three-dimensional swinging motion of the horse's back. The patient reacts to these movement impulses by moving up and down (vertical movement of the spine), back and forth (sagittal movement) and to the right and the left (horizontal movement). The small movements of the spine thus produced bring about a mobilization of the segments involved in movement and there...
Schott HC, Bohart GV, Eberhart SW.Efflux of potassium (K+) and lactate (lac-) from active skeletal muscle during high intensity exercise leads to increased plasma [K+] and [lac-] in venous and arterial blood. The exercise-induced increases in these ions in human athletes is ameliorated, in part, by uptake by noncontracting tissue, reflected by an increase in the arteriovenous difference across these tissues from rest to exercise. To test the hypothesis that these ions are taken up by noncontracting tissue in strenuously exercising horses, plasma [K+] and [lac-] were measured in blood samples collected simultaneously from the c...
Beech J, Lindborg S, Braund KG.Potassium concentrations were measured in semimembranosus muscle, plasma and erythrocytes, and the urinary fractional excretion determined in normal horses and those that had chronic intermittent exercise-associated rhabdomyolysis. Muscle from the rhabdomyolysis horses was also evaluated microscopically. The horses with rhabdomyolysis had a lower muscle potassium concentration on a dry weight basis. Although the wet weight potassium content was also lower, the difference was not significant. Urinary fractional excretion of potassium (and also sodium and chloride) did not differ significantly b...
O'Brien TR, Hornof WJ, Meagher DM.Subchondral lesions were identified in the distal palmar region of the third metacarpus in 21 fetlock joints of 15 Thoroughbred horses. The lesions were more commonly identified on the lateromedial and flexed lateral projection, with the flexed lateral projection permitting optimal visualization of the lesion. Lesions appeared as poorly marginated, radiolucent defects and were located at the level of the base of the proximal sesamoid bones. The shape and distribution of the radiolucent defects were: crescent, 4; flattened, 4; shallow concavity, 5; deep concavity, 3; oval, 3; and circular, 2. S...
Gasthuys F, Vandamme R, De Moor A, De Meurichy W.A commercial neuroleptanalgesic acepromazine-etorphine combination administered intramuscularly to four horses produced a severe tachycardia and an increase in muscular tone, together with hypoxaemia, hypercapnia, metabolic acidosis associated with an increase in the packed cell volume and hyperglycaemia. No electrolyte changes were found. After reversal of the action of etorphine with diprenorphine, there was a prolonged decrease in the calcium and phosphorus serum concentrations and decreases in the packed cell volume and the total protein serum concentration. In a second experiment on the s...
Bolwell CF, Rogers CW, French NP, Firth EC.There is increasing evidence suggesting that early exercise in Thoroughbred racehorses may be beneficial to the development of the musculoskeletal system. At present, information on the exercise programmes and health problems of individual yearlings during a sales preparation is scant. Objective: To describe the exercise and health problems of Thoroughbred yearlings during preparation for sales, and to identify variations in exercise between and within farms. Methods: A prospective cohort study was used to collect exercise and health information from 18 farms across New Zealand. Daily exercise...
Koh RB, Harrison TM.Over the past years, the concept of pain management in veterinary medicine has evolved and led to the establishment of a new concept of multimodal approach to pain management, as the current standard of care. The use of multimodal analgesia combining pharmacologic and nonpharmacologic techniques not only helps optimize the quality and efficacy of analgesia but also may prevent the development of chronic or persistent pain. During the past decade, acupuncture has become more popular and evolved into one of the most used forms of integrative medicine interventions and nonpharmacologic therapeuti...
Adachi M, Aoi S, Kamimura T, Tsuchiya K, Matsuno F.Quadrupedal mammals have fore-aft asymmetry in their body structure, which affects their walking and running dynamics. However, the effects of asymmetry, particularly in the transverse plane, remain largely unclear. In this study, we examined the effects of fore-aft asymmetry on quadrupedal trotting in the transverse plane from a dynamic viewpoint using a simple model, which consists of two rigid bodies connected by a torsional joint with a torsional spring and four spring legs. Specifically, we introduced fore-aft asymmetry into the model by changing the physical parameters between the fore a...
Albu I, Georgia R, Georoceanu M.The Haversian canal system in the diaphysial compacta of the femur in 4 mammalian species (dog, pig, bovine, horse) was studied on the decalcified bone using a method developed by the authors. In the microscopic studies we found that in all species the network aspects vary with the depth of the compacta layer. In all layers, there is a background of longitudinal canals with more or less regular trajectories describing large curves. The anastomoses linking them are main elements that define the variety of the network aspects both from layer to layer and from species to species. The canal densit...
McGuigan MP, Walsh TC, Pardoe CH, Day PS, Wilson AM.Previous studies have implicated tension in the deep digital flexor tendon (DDFT) in the rotation of the distal phalanx (DP) after the breakdown of the dorsal laminae caused by laminitis. Howeveer, once the DP has rotated, the DDFT should become shorter, reducing the force it exerts on the DP. Objective: To compare DDFT force and ground reaction forces (GRFs) in normal ponies and ponies with rotation of the DP as a sequel to laminitis. Methods: Six normal ponies (Group 1) and 6 sound ponies with 6-13 degrees of rotation of the DP in relation to the dorsal hoof wall (Group 2) were assessed at t...
Hennessy SE, Cudmore L, Jackson LP, Vasey JR, Russell T.To (1) develop an arthroscopic approach to the subextensorius recess of the lateral femorotibial (LFT) joint in foals and (2) report its use in foals with LFT joint sepsis. Methods: (1) Anatomic study and (2) retrospective case series. Methods: (1) Cadaveric hind limbs (n = 32 foals) to delineate the anatomy of the subextensorius recess; 13 foal limbs for cadaver surgery to assess the approach to the subextensorius recess; and (2) foals (n = 8) with LFT joint sepsis. Methods: (1) The LFT joint was distended and examined ultrasonographically. Dissection was used to document periarticular landma...