The vertebrae in horses form a critical component of the equine skeletal system, providing structural support and facilitating movement. Horses possess a series of vertebrae categorized into five regions: cervical, thoracic, lumbar, sacral, and caudal. These vertebrae protect the spinal cord and serve as attachment points for muscles and ligaments, contributing to the horse's posture and locomotion. Variations in vertebral anatomy can influence a horse's performance and susceptibility to certain conditions. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, biomechanics, and clinical implications of vertebral health in horses.
Nielsen JV, Berg LC, Thoefnert MB, Thomsen PD.Intra-articular facet joint injection is an established diagnostic procedure in human medicine but there are no reports on its reliability in equine practice. Objective: To investigate the accuracy of ultrasound-guided intra-articular injections of the cervical facet joints and to estimate factors influencing the accuracy. Methods: Sixty injections with blue dye were performed on the facet joints between 2nd and 7th cervical vertebra (C2-C7) on horses subjected to euthanasia for nonorthopaedic reasons. The facet joints were subsequently dissected to verify accuracy of deposition. Results: Seve...
Faber MJ, van Weeren PR, Schepers M, Barneveld A.In order to objectively quantify the effect of manipulation on back-related locomotion anomalies in the horse, a recently developed kinematic measuring technique for the objective quantification of thoracolumbar motion in the horse was applied in a dressage horse that was suffering from a back problem. In this horse, clinically, a right-convex bending (scoliosis) from the 10th thoracic vertebra to the second lumbar vertebra was diagnosed. As a result, there was a marked asymmetric movement of the thoracolumbar spine. Functionally, there was severe loss of performance. Thoracolumbar motion was ...
MacGillivray KC, Graham TD, Parente EJ.A 2-year-old male Thoroughbred was evaluated for multiple firm, raised nodules of the maxilla and mandible that had been present since 6 months of age. The horse was evaluated as a yearling with a final histologic diagnosis of fibrosarcoma. As a 2-year-old, the colt made a loud upper airway sound and was agitated after strenuous exercise. Results of upper airway endoscopy indicated severe narrowing of the nasal passages and pharynx with normal resting function. Radiography revealed multiple circular bony lesions in the mandible, maxilla, multiple long bones, and cervical vertebrae. Biopsy spec...
Ranner W, Gerhards H, Klee W.There is a regularly high proportion of x-ray findings indicating a pathological deterioration of the equine vertebral column which do not correlate with the clinical symptoms. Therefore, palpation remains one of the most important clinical examination methods to determine whether or not a horse is suffering from back pain. The aim of this study was to check the validity of palpation results of horses with an assumed back problem. The palpation results of 167 horses were evaluated in retrospect: If the palpation proceeds under following conditions, positive palpation results agree with an prim...
Faber M, Johnston C, van Weeren PR, Barneveld A.We tested the hypothesis that repeatability of a standardised protocol for quantifying back kinematics is sufficiently high not to prevent its use in the clinical evaluation of horses with back problems. We investigated the extent to which differences between laboratories may affect the results when a standardised protocol is used. As a clinical tool, movement analysis techniques are helpful for the objective and quantitative assessment of kinematics. Knowledge about the repeatability of the kinematic data is very important. The present study investigates the repeatability of back kinematics i...
Walmsley JP, Pettersson H, Winberg F, McEvoy F.The surgical treatment of impingement of dorsal spinous processes (DSPs) at 2 equine veterinary hospitals following a similar diagnostic and surgical protocol is described with special reference to the diagnosis and case selection. The diagnosis was made from clinical examination and results of radiography and diagnostic analgesia of the affected sites. Scintigraphy was also used as an aid to diagnosis at one hospital. Surgical treatment was generally recommended when conservative treatment, which included 3-9 months rest, intralesional corticosteroids and physiotherapy, had failed. The DSPs w...
Mackie MK.A 13-year-old, Thoroughbred gelding presented with a 3-year history of progressive ataxia of all 4 limbs. Physical and neurological examinations indicated a compressive lesion affecting the cervical spinal cord. Radiographs confirmed a lesion, and a myelogram a narrowing of the spinal canal at cervical vertebrae (6-7). Necropsy confirmed cervical stenotic myelopathy.
Haussler KK, Bertram JE, Gellman K, Hermanson JW.Understanding the pathophysiology of equine back problems, for clinical evaluation, treatment or injury prevention, requires understanding of the normal 3-dimensional motion characteristics of the vertebral column. Recent studies have investigated regional vertebral kinematics; however, there are no reported measures of direct in vivo segmental vertebral kinematics in exercising horses. Relative movements between 2 adjacent vertebrae were recorded for 3 horses that were clinically sound and did not have a known history of a back problem. A transducer consisting of 2 fixtures and an array of li...
Faber M, Johnston C, Schamhardt HC, van Weeren PR, Roepstorff L, Barneveld A.Most research on equine kinematics has previously been performed in the walking and/or trotting animal. This is also true for the few studies on the kinematics of the equine back. These studies have, for the major part, focused on the flexion-extension movement in the sagittal plane. However, vertebrae can rotate in 3 dimensions. This study was designed to determine all 3 rotations in various segments of the vertebral column of a cantering horse. Five Dutch Warmblood horses were measured during treadmill canter (7.3 m/s). Steinmann pins were inserted into the dorsal spinous processes of 8 thor...
Scheffer CJ, Blaauw G, Dik KJ, Sloet van Oldruitenborgh-Oosterbaan MM.A mini-Shetland stallion was referred with bilateral pruritus localized to the anterior neck. More detailed clinical examination also revealed ataxia, and diagnostic imaging, including pre- and post-contrast computed tomography, revealed an old fracture of C2. Spinal cord compression was diagnosed. The probable causal relation between the fracture, the ataxia, and the localized pruritus seems comparable to the 'contusio cervicalis posterior' in humans, in which spinal cord trauma may cause pruritus in the associated dermatome.
Faber M, Johnston C, Schamhardt H, van Weeren R, Roepstorff L, Barneveld A.To determine movements of the vertebral column of horses during normal locomotion. Methods: 5 young Dutch Warmblood horses that did not have signs of back problems or lameness. Methods: Kinematics of 8 vertebrae (T6, T10, T13, T17, L1, L3, L5, and S3) and both tuber coxae were determined, using bone-fixated markers. Measurements were recorded when the horses were trotting on a treadmill at a constant speed of 4.0 m/s. Results: Flexion-extension and axial rotation were characterized by a double sinusoidal pattern of motion during 1 stride cycle, whereas lateral bending was characterized by 1 pe...
Farber M, Schamhardt H, van Weeren R, Barneveld A.To determine the validity of using skin-fixated markers to assess kinematics of the thoracolumbar vertebral column in horses. Methods: 5 Dutch Warmblood horses without abnormalities of the vertebral column. Methods: Kinematics of T6, T10, T13, T17, L1, L3, L5, S3, and both tuber coxae were determined by use of bone-fixated and skin-fixated markers. Three-dimensional coordinate data were collected while horses were walking and trotting on a treadmill. Angular motion patterns were calculated and compared on the basis of 2-dimensional analysis of data from skin-fixated markers and 3-dimensional a...
Faber M, Schamhardt H, van Weeren R, Johnston C, Roepstorff L, Barneveld A.To determine kinematic movements of the vertebral column of horses during normal locomotion. Methods: 5 Dutch Warmblood horses without apparent lameness or problems associated with the vertebral column. Methods: Kinematics of 8 vertebrae (T6, T10, T13, T17, L1, L3, L5, and S3) and both tuber coxae were determined, using bone-fixated markers. Horses were recorded while walking on a treadmill at a constant speed of 1.6 m/s. Results: Flexion-extension was characterized by 2 periods of extension and flexion during 1 stride cycle, whereas lateral bending and axial rotation were characterized by 1 p...
Haussler KK.Pathologic changes have been observed at the spinous processes, intervertebral articulations, and sacroiliac joints in horses. Varying severity of degenerative articular changes are found in many articular processes, intertransverse, lumbosacral, and sacroiliac joints. Pathologic lesions tend to affect multiple vertebral locations within a specimen. Further studies need to be conducted to evaluate the clinical significance of the numerous vertebral and pelvic pathologic findings found in a sample of Thoroughbred racehorses that died because of unrelated injuries. Increased knowledge of osseous...
Haussler KK.A thorough knowledge of equine spinal anatomy, biomechanics, and potential pathology is required to understand the principles and theories behind chiropractic and to apply its techniques properly. Chiropractic provides additional diagnostic and therapeutic means that may help equine practitioners to identify and treat the primary cause of lameness or poor performance. Specialized training in the evaluation and treatment of vertebral joint dysfunction and neuromusculoskeletal disorders places chiropractic in the forefront of conservative treatment of spinal-related disorders. Nevertheless, limi...
Denoix JM.Knowledge of the normal functional behavior and mechanical properties of the vertebral column is important to understand the pathogenesis of back lesions, to identify the clinical manifestations of back pain, and to ensure a rational approach to physical therapy. The purpose of this article is to present a synthesis of in vivo and in vitro data obtained from different but complementary investigations. Presently, in vivo studies are limited; few gait-specific kinematic and electromyographic investigations are in process. Higher stresses to reach the maximal range of intervertebral motion can be...
Jeffcott LB.This article is presented as an introduction to the complex subject of back pain and its management in horses. It considers some of the historical perspectives and deals with some of the limiting factors when attempting to evaluate back pain. The clinical indications of a back problem are considered, as is the important distinction of primary versus secondary back pain. Finally, a list of considerations capable of causing back pain and impaired performance is included.
Haussler KK, Stover SM, Willits NH.To describe the prevalence, characteristics, and severity of soft-tissue and osseous lesions in the caudal portion of the thoracic and lumbosacral vertebral column and pelvis in Thoroughbred racehorses. Methods: 36 Thoroughbred racehorses that died or were euthanatized at California racetracks between October 1993 and July 1994. Methods: Lumbosacral and pelvic specimens were collected and visually examined for soft-tissue and osseous lesions. Results: Acute sacroiliac joint injury was observed in 2 specimens. Signs of chronic laxity or subluxation of the sacroiliac joint were not observed in a...
Maierl J, Zechmeister R, Schill W, Gerhards H, Liebich HG.Fractures of the first two cervical vertebrae, atlas and axis, may occur in foals for different reasons, e.g. in cases of a fall, going head over heels or when being hit by a hoof. The tentative clinical diagnosis can be confirmed by x-raying the standing animal, with aid of computed tomography in the anaesthetized foal respectively. The growth plates however, and their time of closure have to be considered when interpreting radiographs. In the atlas there are two ventrolateral plates and one dorsomedian cartilagineous plate. Only the dorsal plate, however, can be found in the dorsoventral pro...
Haussler KK, Stover SM.Thirty-six Thoroughbred racehorses that died at California racetracks between October 1993 and July 1994 were evaluated for stress fractures in the caudal portion of the thoracic and lumbosacral regions of the spine and the pelvis. The lumbosacral spine and pelvis were collected, debrided of soft tissues and examined visually for the presence of an incomplete fracture line and focal periosteal proliferation, characteristic of a stress fracture. Sixty-one per cent of specimens had evidence of stress fracture in the caudal portion of the thoracic and lumbosacral regions of the spine and the pelv...
Haussler KK, Stover SM, Willits NH.To describe the incidence and types of gross osseous developmental variations and ages of physeal closure in the caudal portion of the thoracic and lumbosacral spine and the pelvis in a sample of Thoroughbred racehorses. Methods: Thoroughbred racehorses (n = 36) that died or were euthanatized at California racetracks between October 1993 and July 1994. Methods: Lumbosacropelvic specimens were collected, and all soft tissues were removed. The osseous specimens were visually examined. Results: Only 22 (61%) specimens had the expected number of 6 lumbar and 5 sacral vertebrae. Eight (22%) specime...
Hestvik G, Ekman S, Lindberg R.A novel case where onchocercosis was identified as a cause of cervical myelopathy in the horse is described. A 15-year-old Connemara mare was euthanized due to progressive locomotion disturbance. Postmortem examination revealed soft-tissue swelling in the intervertebral joint capsule of C6-7 with narrowing of the vertebral canal. On light microscopy, axonopathy was pronounced in the corresponding segment of the spinal cord. Fibrous tissue and eosinophilic granulomas were found in the joint capsule, together with parasites identified histologically as Onchocerca sp.
Yang C, Weisbrode S, Yardley J, Schroeder E, Premanandan C.Ischaemia-induced physeal injury has not been described previously in the horse. A 1-month-old Quarter horse foal was submitted for necropsy examination due to an acute onset of ataxia followed by a 4-week history of progressive decline. Focal narrowing of the spinal canal due to ventral compression by the rotation of the cranial aspect of the third cervical vertebra (C3) was observed. The metaphysis and diaphysis of C3 were markedly shortened and white-tan in colour. Microscopically, there was complete loss of the dorsal compact bone of C3 and replacement of 80% of the physis that runs parall...
Newton-Clarke MJ, Guffoy MR, Dykes NL, Divers TJ.A haemangiosarcoma in a horse resulted in ataxia affecting all four legs, a low head carriage and a reluctance to flex the neck. Ancillary diagnostic procedures included the analysis of cerebrospinal fluid, standing lateral cervical radiographs and a myelogram. Post mortem a tumour was found which involved the body of the second cervical vertebra and the associated hypaxial muscles, with secondary intravertebral extradural infiltration and focal compressive myelopathy. A histological examination showed that the tumour was a haemangiosarcoma.
Markel MD, Madigan JE, Lichtensteiger CA, Large SM, Hornof WJ.Over a 4-year period, vertebral body abscess was diagnosed in 5 young cattle. The laboratory findings in most of these cases did not suggest a diagnosis of vertebral body abscess. The most important basis for diagnosis of this condition was a thorough neurologic examination. In 4 cases, necropsy revealed abscesses in the lungs or thoracic cavity as well, suggesting that a history of pneumonia preceding paresis may favor the diagnosis of vertebral body abscess.
Gaughan EM, Fubini SL, Dietze A.Over an 8-year period, 14 horses were admitted to the New York State College of Veterinary Medicine for evaluation of fistulous withers. Of the 14 horses, 11 were treated surgically and 3 were not treated. Surgical techniques involved radical excision of the affected soft tissue and spinous processes of affected vertebrae. Recurrence rate was 30%, and these horses required additional surgery to resolve the problem.
Samol MA, Uzal FA, Blanchard PC, Arthur RM, Stover SM.The most prevalent causes of death in racehorses are musculoskeletal injuries, causing ~83% of deaths within the racing industry in California and elsewhere. The vast majority of these injuries have preexisting lesions that predispose to fatal injury. A 4-y-old Thoroughbred colt suffered an acute suspensory apparatus failure, including biaxial proximal sesamoid bone fractures of the right front fetlock, causing loss of support of the fetlock joint and consequent fall with fractures of the cervical and sacral spine. Cervical fracture caused spinal cord damage that resulted in sudden death. A pr...
Cudmore LA, Groenendyk JC, Hodge P, Church S.This case report describes neurological signs associated with a pyogranulomatous lesion within the sacral vertebral canal of a horse. The clinical findings included urinary overflow incontinence and reduced anal, perianal and tail tone. The horse failed to respond to medical management and a guarded prognosis for return to athletic performance initiated the decision for euthanasia.
Cavani F, Fini M, de Terlizzi F, Cadossi M, Ciminelli L, Ortolani S, Cherubini R, De Aloysio D, Giavaresi G, Cadossi R, Canè V.Osteoporosis involves alterations, not only in density, but also in the architectural organisation of the bone; in particular, trabecular orientation, following the skeletal load directions, lends a high degree of stiffness to the whole bone. We investigated the relationship between trabecular orientation, density, stiffness and ultrasound (US) propagation in two orthogonal directions (par. = parallel to, and ort. = orthogonal to the main orientation of the trabeculae) in cylindrical equine bone specimens (thoracic vertebrae) where a preferential orientation is present. A total of 15 cylinders...
Biedrzycki AH, Elane GL. Interspinous ligament desmotomy (ISLD) has been shown to improve the comfort of horses diagnosed with overriding dorsal spinous processes (DSP), but its effects on spine mobility are unknown. To objectively quantify the change in mobility of thoracic vertebrae following ISLD using CT and medical modeling software. Prospective cadaveric manipulation of seven equine thoracolumbar spines collected from T11-L1. Spines were collected from T11-L1 with the musculature intact. Flexion and extension phases were achieved with a ratchet device calibrated to 2000N. Bone volume CT scans were performed ...
Klide AM.Lumbar and thoracic vertebrae of the extinct horse, Equus occidentalis, were examined for gross and radiographic evidence of overriding spinous processes. Of 2,661 vertebrae examined, 580 had intact spinous processes. Thirty-six intact spinous processes, which appeared grossly similar to overriding spinous processes in the modern domestic horse, E caballus caballus, were radiographed. Of these 36 vertebrae, 2 had radiographic signs compatible with a radiographic diagnosis of overriding spinous processes, ie, radiographically observed lysis and/or sclerosis. Seemingly, weight bearing or other s...
Adams SB, Steckel R, Blevins W.Diskospondylitis was diagnosed in 5 horses admitted to the Purdue University Large Animal Clinic during a 3-year period. Each horse had evidence of cervical pain. Clinical signs and radiography were useful for identifying the diskospondylitis. Cerebrospinal fluid was normal.
Smyth GB.A 3-year-old Thoroughbred filly examined because of poor performance after a fall was found to be ataxic. Radiography revealed a linear defect in the right dorsal cranial articular facet of the fifth cervical vertebra. The defect was thought to be a fracture or a developmental defect. Arthrodesis and stabilization were achieved by ventral implantation of a Bagby basket in the articulation between the fourth and fifth cervical vertebrae. The ataxia resolved within 4 months, and the filly was able to resume full race training.
Bergmann W, Vernooij JCM, Grinwis GCM, Gröne A.Osteochondrosis dissecans (OCD) of articular process joints (APJs) is involved in cervical vertebral compressive myelopathy (CVM). Biomechanical forces, important in development of OCD, depend on joint conformation. Oval and flat APJ surfaces are considered normal. Objective: To identify and grade gross shape variation of cervical and cranial thoracic APJ surfaces and determine association with histological evidence of osteochondrosis. Methods: Case series. Methods: Eight hundred and four cervical and cranial thoracic APJ surfaces of 30 foals were evaluated for shape(s) and grades, and were co...
Scheffer CJ, Blaauw G, Dik KJ, Sloet van Oldruitenborgh-Oosterbaan MM.A mini-Shetland stallion was referred with bilateral pruritus localized to the anterior neck. More detailed clinical examination also revealed ataxia, and diagnostic imaging, including pre- and post-contrast computed tomography, revealed an old fracture of C2. Spinal cord compression was diagnosed. The probable causal relation between the fracture, the ataxia, and the localized pruritus seems comparable to the 'contusio cervicalis posterior' in humans, in which spinal cord trauma may cause pruritus in the associated dermatome.
Gerber H, Ueltschi G, Diehl M, Schatzmann U, Straub R.For various anamnestic reasons the cervical vertebral column of 78 horses was examined radiologically. Statistical comparisons showed that male "warmbloods" were more frequently affected than was expected. Our horses were older than comparable animals in the international literature. Independently of their history the radiologic diagnosis of "cervical spondylarthrosis" was established in 56 horses. Arthrosis and other conditions were clinically manifested by spinal ataxia (44 horses) or mechanical impairment of the neck's mobility (21 horses). 10 of the arthrotic patients had synovial cysts ca...
Reardon R, Bailey R, Walmsley J, Heller J, Lischer C.The mechanical properties of equine cervical vertebrae joined by implants have not yet been reported. Locking compression plates (LCP) may provide a useful alternative system to the commonly used stainless steel kerf-cut cylinders (KCC) currently used for fixation of cervical vertebrae in horses. Objective: The objectives of this study were to establish a method for biomechanical testing of equine C4-C5 articulations and to compare the biomechanical properties of cadaveric spines stabilised with KCC and LCP. Methods: Twenty-four equine cadaveric cervical spines were size measured from radiogra...
O'Sullivan S, McGowan CM, Junnila J, Hyytiäinen HK.Impinging dorsal spinous processes (IDSP) are typically diagnosed and graded using radiography, during which the effect of the horses' thoracolumbar posture on the interspinous spaces is not commonly considered. Posture can be altered from a spontaneous, relatively extended, or lordotic, position by manual facilitation of thoracic flexion ('thoracic lift'). This study aimed to ascertain if the thoracic vertebral interspinous space distances were increased by using facilitated thoracic flexion to alter the posture in horses diagnosed with IDSP. Seven horses of mixed breed and sex, median age 9....
Krunajević T, Bergsten G.The clinical and pathological details of a case of ataxia in a 3-month-old colt are described. A marked protrusion into the vertebral canal of the body of the 3rd cervical vertebra was observed. C and C were immovably joined so that the deformity could not be corrected by extension of the spinal column at this point. There was a compression of the spinal cord corresponding to the protrusion. The cause of this luxation could not be established. It may be assumed that the distortion was congenital, or caused by trauma at an early stage and that clinical symptoms could be observed only when, a ma...
Kernot N, Butler R, Randle H.Conditions of the equine caudal neck (C5-C7) are thought to be associated with various clinical signs. However, little investigation has been undertaken to isolate clinical indicators associated with specific conditions of the equine caudal cervical spine. This systematic review aimed to evaluate associations of clinical signs with anatomical malformation of caudal cervical vertebrae, spinal cord compression of the caudal cervical spine, and arthropathy of the caudal cervical articular process joints (APJs). A literature search was carried out using Google Scholar in accordance with PRISMA (Pr...
Every LJ, Hostnik ET, Hostnik LD, Yardley J, Shore-Khirallah AT, Thompson A, Linn SC.Tracheal collapse in horses is reportedly uncommon; however, American Miniature Horses are more commonly affected. There is no description of the tracheal luminal diameter of American Miniature Horses, making early detection of tracheal luminal narrowing difficult. Objective: To 1) describe radiographic tracheal luminal diameter in clinically normal American Miniature Horses, 2) report the prevalence of subclinical tracheal collapse in a population of American Miniature Horses, and 3) use tracheal videofluoroscopy to quantify variation in tracheal luminal diameter throughout the respiratory c...
Shearer TR, Kinsley MA, Pease AP, Patterson JS.The purpose of this study was to develop a minimally invasive approach to equine cervical articular facet joints for application of an ND:YAG LASER and to evaluate the effects of the laser fiber on the surrounding tissue. Under general anesthesia, an ND:YAG LASER was used to apply 2000 J of energy to 5 cervical articular facet joints in 3 horses (15 joints total). Horses were euthanized and the cervical facets and spinal cords were examined grossly and histologically. Gross pathology of the articular facets revealed evidence of articular cartilage charring and diffuse roughening of the surface...
