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.
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...
Hillyer MH, Innes JF, Patteson MW, Barr AR.Discospondylitis, of presumed bacterial origin, was diagnosed in an adult thoroughbred racehorse. The clinical signs were vague and associated with abnormal mobility of the neck and forelimbs. Clinical pathology showed only a non-specific inflammatory response. A scintigraphic examination revealed the site of the lesion and the diagnosis was confirmed by the identification of radiographic changes affecting two thoracic vertebrae. A prolonged course of antimicrobial agents produced a complete recovery and the horse returned to full athletic use.
Rivas LJ, Hinchcliff KW, Robertson JT.Cervical meningomyelocele, spina bifida, and hydrocephalus were diagnosed in a newborn miniature colt that was unable to stand and had a cystic mass in the caudal portion of the dorsal cervical region. Results of physical examination and ultrasonographic imaging of the brain supported the diagnosis of hydrocephalus. Results of radiographic evaluation of the vertebral column were consistent with spina bifida at C5-C6. Fluid aspirated from the cervical mass resembled CSF. Radiography of the cervical region after injection of iohexol into the mass revealed herniation of the spinal cord through a ...
Doige CE.A midsagittal centrum cleft of T5-6, malformation and fusion of T3-7, intra- and extraspinal cyst, and myelodysplasia were found in a 3-month-old female Arabian foal that had experienced posterior ataxia since birth. Based on studies in other species, ecto-endodermal adhesions early in embryogenesis leading to formation of an enterogenous cyst is the most probable pathogenesis.
Barnes HG, Tucker RL, Grant BD, Roberts GD, Prades M.A traumatic fracture of C2 was diagnosed radiographically in a 1-year-old German Warm-blood stallion. Fracture configuration was difficult to see on survey radiographs. Computed tomography yielded a more accurate assessment of the fracture and facilitated fracture repair with cortical lag screws. Precise screw placement, to avoid spinal cord damage, was obtained by use of computed tomography. Follow-up radiography revealed normal bone healing, and the horse was in dressage schooling 24 months after surgery.
Tomizawa N, Nishimura R, Sasaki N, Hayashi Y, Senba H, Hara S, Kadosawa T, Takeuchi A.Morphological differences between cervical vertebrae were statistically analyzed in ataxic foals to clarify abnormal structural factors in the pathogenesis of this problem. At first, multiple regression analysis and cluster analysis were performed with 28 variables in C3-C7 of 39 control foals without lameness. As a result, there were no sex differences in the growth of all cervical vertebral sites, and the most suitable categorization of the age of the foals was 3 clusters of 8 months old or younger, 9-12 months old and 13 months old or older in any sites in the cervical vertebrae. Twenty-eig...
Tomizawa N, Nishimura R, Sasaki N, Kadosawa T, Senba H, Hara S, Takeuchi A.Cervical myelography and survey radiography was performed on 12 light breed wobbling foals and a new radiographic measurement method was applied for more accurate diagnosis of cervical vertebral instability. Ratios of stenosis of the spinal canal on survey radiography and myelography using relative values in an individual foal were defined on radiograms of lateral flexed position of mid-cervical region, and coincidence between the ratios and histopathological lesions in the cervical spinal cord was investigated. Five of 6 foals had ratios of stenosis on myelography more than 40% at the interve...
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.
Tomizawa N, Nishimura R, Sasaki N, Nakayama H, Kadosawa T, Senba H, Takeuchi A.Nineteen wobbling foals (17 males and 2 females) showing lameness of hindlimbs at 6 to 21 months of age were investigated radiographically and histopathologically. Minimum sagittal diameter (MSD), minimum flexion diameter (MFD) and minimum dural sagittal diameter (MDD) were measured on plain radiograms or myelograms taken at neutral and flexed positions as indicators of narrowed vertebral canal. After necropsy, the cervical spines and the spinal cord were examined macroscopically and respectively the relationships between radiographic findings and the corresponding morphological lesions were e...
Mayhew IG, Donawick WJ, Green SL, Galligan DT, Stanley EK, Osborne J.Over a period of 5 years on a central Kentucky Thoroughbred stud farm 132 foals were evaluated for the presence of cervical vertebral malformation (CVM). Lateral cervical vertebral radiographs were obtained on 70 standing foals. These radiographs were evaluated semi-quantitatively and scored numerically for the presence of stenosis of the vertebral canal, enlarged physeal growth plates, caudal extension of the dorsal border of the orifice of the vertebral canal, angular fixation, delayed ossification of bone and degenerative joint disease. From these scores a total CVM score was given for each...
Moore BR, Reed SM, Robertson JT.Seventy-three horses with cervical stenotic myelopathy underwent cervical vertebral interbody fusion (n = 63) or dorsal laminectomy (n = 10). Neurologic function improved in 77% of horses, and 46% of horses achieved athletic function (racing, race training, or pleasure riding) after cervical vertebral interbody fusion for static and dynamic spinal cord compressive lesions. Neurologic status improved in 4 of 10 horses after dorsal decompression for static compressive spinal cord lesions. The duration of clinical signs prior to surgical intervention was shorter for horses that achieved athletic ...
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.
Furr MO, Anver M, Wise M.Intervertebral disk prolapse was diagnosed in a mature horse with clinical signs of caudal ataxia. Radiography and myelography demonstrated a collapsed intervertebral space and loss of the dorsal and ventral dye columns. Results of CSF analysis were normal, as were a CBC and serum biochemical profile. High CSF WBC count and high CSF creatine kinase activity were noticed following acute neurologic deterioration. While common in certain breeds of dogs, intervertebral disk prolapse is rarely reported in horses. It should be considered in the differential diagnosis of horses with caudal ataxia.
Stewart RH, Reed SM, Weisbrode SE.We compared the frequency and severity of osteochondrosis lesions in young Thoroughbred horses with cervical stenotic myelopathy (CSM) vs that in clinically normal Thoroughbreds of the same age. All lesions of the cervical vertebrae and appendicular skeleton were classified histologically as osteochondrosis or nonosteochondrosis and were measured for severity. Minimal sagittal diameter was significantly smaller in horses with CSM from C2 through C6; no difference was detected at C7. Severity of cervical vertebral osteochondrosis was greater in the horses with CSM, however frequency was not dif...
Ekman S.Lesions in the cervical spine of 28 young horses (Standardbred Trotters and Swedish Warmbloods), killed because of longstanding or severe ataxia, are described. The material consists of all horses with ataxia available for necropsy and presented to the large animal clinic of the School of Veterinary Medicine, Uppsala and the Animal Hospital in Helsingborg during 1981 through 1983. After a clinical and radiographic examination, including myelography in all but 2 cases, the horses were killed and necropsy was performed. The cases were divided into three categories based on the radiographic and p...
Nappert G, Vrins A, Breton L, Beauregard M.A retrospective study of 19 ataxic horses admitted to the College of Veterinary Medicine of the University of Montreal during the period of January 1985 to December 1988 is presented. There were 11 cases of cervical vertebral malformation, four of equine degenerative myeloencephalopathy, two of equine protozoal myeloencephalitis, one each of vertebral osteomyelitis and intervertebral disc protrusion. The clinical diagnosis of ataxia in horses requires neurological, radiographic, myelographic, and laboratory examinations.
Kirberger RM, Gottschalk RD.The clinical, radiological and anatomical changes in a yearling foal with kyphoscoliosis are described. The lesion was due to a primary malformation of the eleventh, twelfth, fourteenth and fifteenth thoracic vertebral bodies resulting in hemivertebrae. Secondary changes occurred in the laminae, pedicles, spinous and articular processes of the affected vertebrae and the adjacent vertebrae. The possible pathogenesis and differential diagnosis are discussed.
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...
Huggons N.A Thoroughbred yearling was presented with neurological, radiographic, and myelographic abnormalities consistent with cervical vertebral stenotic myelopathy. Surgical correction was performed by using ventral cervical interbody fusion at 3 intervertebral spaces. The patient recovered uneventfully from surgery. The neurological status remained unchanged initially; however, significant improvement was noted 37 weeks postoperatively. Un Thoroughbred d’un an a été présenté avec des anomalies neurologiques, radiographiques et myélographiques compatibles avec une myélopathie sténosée des ...
Ekman S.Lesions in the cervical spine of 28 young horses (Standardbred Trotters and Swedish Warmbloods), killed because of longstanding or severe ataxia, are described. The material consists of all horses with ataxia available for necropsy and presented to the large animal clinic of the School of Veterinary Medicine, Uppsala and the Animal Hospital in Helsingborg during 1981 through 1983. After a clinical and radiographic examination, including myelography in all but 2 cases, the horses were killed and necropsy was performed. The cases were divided into three categories based on the radiographic and p...
Graubner C, Bergmann W, Gerber V, Veraa S, Oevermann A, Wijnberg I.Aims: To determine the relation between quantitative electromyography (QEMG) of the cervical ventral serratus muscle, radiographic findings and post-mortem gross and histopathological examination in order to calculate the ability of QEMG to localize the region of cervical compressive neuropathy and myelopathy in horses. Methods: In this clinical, non-randomised, partially blinded study (QEMG and histology), 36 warmblood horses with clinical suspicion of cervical spine disease were examined with QEMG in different segments of the ventral serratus muscle. Results were compared to normative data. ...
Mayaki AM, Abdul Razak IS, Mohd Adzahan N, Mazlan M, Abdullah R.Equine chronic back pain (CBP) has been linked to different pathologic processes, which directly or indirectly involve spinal structures. Thus, making diagnosis and management very challenging with most horses with the condition recommended for early retirement from athletic activity. This study described the spinal cord lesions and the development of reactive microgliosis and astrocytosis in the spinal cords of horse with CBP. Thoracolumbar spinal cord segments from three horses euthanized because of unresolved CBP were dissected and grossly and histopathologically examined. The expression of...
Rovel T, Duchateau L, Saunders J, Vandenberghe F, Vanderperren K.Narrowing of the equine cervicothoracic intervertebral foramina (IF) has the potential to cause forelimb lameness and/or neck pain although limited information is available on CT of the IF. The aims of this retrospective, analytical study were to describe a protocol for quantifying CT cervicothoracic IF size; evaluate the repeatability of IF size measures; test associations between IF size and adjacent articular process (AP) size, ventral extent, and anatomic location; and determine the proportion of IF with narrowing. Computed tomographic images were acquired in 20 Warmblood horses that prese...
Hillyer MH, Innes JF, Patteson MW, Barr AR.Discospondylitis, of presumed bacterial origin, was diagnosed in an adult thoroughbred racehorse. The clinical signs were vague and associated with abnormal mobility of the neck and forelimbs. Clinical pathology showed only a non-specific inflammatory response. A scintigraphic examination revealed the site of the lesion and the diagnosis was confirmed by the identification of radiographic changes affecting two thoracic vertebrae. A prolonged course of antimicrobial agents produced a complete recovery and the horse returned to full athletic use.
Vos Nj.The 'classical' or 'Hangman' neck fracture involves the odontoid peg (process) of the second cervical vertebra (C2), and is described as an axial, dens or odontoid peg fracture in both the veterinary and human literature. Possible surgical treatment in both foals and adult horses requires a technique that allows decompression, anatomical alignment and stabilisation of the odontoid fracture. A limited number of surgical cases in foals have been reported in literature, but never in an adult horse. A mature Irish Thoroughbred racehorse was diagnosed with a type 2a odontoid peg fracture. Clinical ...
Gillen A, Dyson S, Murray R.The results of nuclear scintigraphic examination of the thoracolumbar synovial intervertebral articulations (facet joints) have to date been poorly documented. Objective: To establish an objective scintigraphic grading system for the facet joints; to investigate the relationship between the presence or absence of clinical signs of back pain and increased radiopharmaceutical uptake (IRU); and to compare the results of scintigraphy and radiography. Methods: Nuclear scintigraphic images of the 13th thoracic (T13) to first lumbar (L1) vertebrae were graded subjectively (visual assessment of the im...
Jauch SY, Wallstabe S, Sellenschloh K, Rundt D, Püschel K, Morlock MM, Meenen NM, Huber G.Horse-related injuries are manifold and can involve the upper and lower limbs, the trunk, spine or head. Cervical spine injuries are not among the most common injuries. However, they can be fatal and often result in neurological symptoms. This study investigated the influence of the posture of the cervical spine on the ultimate strength and the pattern of vertebrae failure with the aim to provide some guidance for protective clothing design. Methods: Eighteen human cervical spines, each divided into two specimens (three vertebrae each), were subjected to a simulator test designed to mimic a sp...
Rivas LJ, Hinchcliff KW, Robertson JT.Cervical meningomyelocele, spina bifida, and hydrocephalus were diagnosed in a newborn miniature colt that was unable to stand and had a cystic mass in the caudal portion of the dorsal cervical region. Results of physical examination and ultrasonographic imaging of the brain supported the diagnosis of hydrocephalus. Results of radiographic evaluation of the vertebral column were consistent with spina bifida at C5-C6. Fluid aspirated from the cervical mass resembled CSF. Radiography of the cervical region after injection of iohexol into the mass revealed herniation of the spinal cord through a ...
Thomsen LN, Berg LC, Markussen B, Thomsen PD.Cervical synovial folds have been suggested as a potential cause of neck pain in humans. Little is known about the extent and characteristics of cervical synovial folds in horses. Objective: The objective of this explorative study was to determine the frequency of synovial folds in equine cervical articular process joints and to provide a characterisation of the size and morphology of the synovial folds. Methods: Equine cervical articular process joints from 6 horses were included in the study, ranging from cervical vertebra 2 (C2) to cervical vertebra 7 (C7) bilaterally. The articular process...
Kim HT, Gim TJ, Lee JH.A 53-year-old man had chronic low back and leg pain for four years without any history of trauma or neurological manifestations. There was a reduction in symptoms after a lumbar epidural block. Two hours later after the procedure, the patient complained of perineal numbness and lower extremity weakness. The neurological evaluation revealed loss of sensation in the saddle area and the posterior aspect of the leg. The deep-tendon reflexes were decreased in the leg. The patient was unable to urinate. The MRI revealed a schwannoma at the S3 level of the sacral spine with cauda equina compression. ...
van Zadelhoff C, Ehrle A, Merle R, Jahn W, Lischer C.Impinging processi spinosi in the equine thoracic spine are a common cause of poor performance in the horse. A modified semiquantitative scintigraphic image analysis has been proposed for the evaluation of equine processi spinosi. This technique showed a high inter- and intraobserver agreement when compared to subjective and semiquantitative image analysis. The aim of this retrospective, method comparison study was to evaluate the agreement of the modified semiquantitative scintigraphic image assessment with previous methods of interpretation and to compare these scintigraphic evaluation techn...
Pereira GF, Fenelon ACG, Horr M, Nogueira GM, Delfiol DJZ.The analysis of cerebrospinal fluid has diagnostic, prognostic, and therapeutic value in neurological illnesses in horses. There are different methods for obtaining cerebrospinal fluid, with the collection between the C1 and C2 vertebrae being a more recent methodology, which allows the procedure to be performed in standing patients, without the limitations of general anesthesia and with a low contamination of the sample with blood, presenting itself as a practical alternative. This study evaluated the efficacy and safety of a local dural blockade in healthy horses submitted to cerebrospinal f...
Olstad K, Bugge MD, Ytrehus B, Kallerud AS.The neuro-central synchondrosis (NCS) is a physis responsible for the growth of the dorsal third of the vertebral body and neural arches. When the NCS of pigs is tethered to model scoliosis, stenosis also ensues. It is necessary to describe the NCS for future evaluation of its potential role in equine spinal cord compression and ataxia (wobbler syndrome). Objective: To describe the NCS, including when it and other physes closed in computed tomographic (CT) scans of the cervical spine of foals, due to its potential role in vertebral stenosis. Methods: Post-mortem cohort study. Methods: The cerv...
Loder RT, Walker AL, Blakemore LC.Fractures often occur due to equestrian activities with injury patterns varying by age. The purpose of this study was to investigate in detail fracture patterns and associated demographics in children due to equine activities. Methods: The US National Electronic Injury Surveillance System was queried for all injuries with the consumer product code 1239 (horseback riding) from 2000 to 2023. Those <16 years old with fractures were extracted. Statistical analyses were performed with SUDAAN 11.0.01™ software to obtain national estimates. Results: There were an estimated 101,677 patients with a f...
Boyd JS.A radio-opaque marker was injected intramuscularly at different levels and with needles of different lengths into the cervical musculature of a series of ponies and horses which were under profound anaesthesia prior to euthanasia. Subsequently the necks were sectioned and radiographed to determine the fate of the injected material. The results indicated that care was necessary in the selection of the level for injection in order to prevent deposition of material on to the periosteal surface of the cervical vertebrae or on to the ligamentum nuchae and fascial sheaths. The muscle mass over the t...
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.
Jacobsen B, Venner M, Gerdwilker A, Wohlsein P.A ventral meningomyelocele was found in a five week old, male German warmblood foal which exhibited central nervous symptoms. This rare malformation in horses may be caused by absent or defective fusion of vertebral bodies leading to herniation of the spinal cord and meninges with subsequent degenerative alterations of the spinal cord.
Kondo T, Sato F, Tsuzuki N, Watanabe K, Horiuchi N, Kobayashi Y, Yamada K.The purpose of this observational study was to determine the characteristic computed tomographic (CT) myelography findings of cervical vertebral stenotic myelopathy (CVSM) lesions in Thoroughbred horses. A total of 23 Thoroughbred horses (age range, 155-717 days on CT examination; mean, 410.9 days) were analyzed. All 23 Thoroughbred horses underwent unenhanced radiography, radiographic myelography, and CT myelography. Unenhanced radiographs were observed the presence of cervical vertebral malalignment and osseous lesions. Radiographic myelograms were observed for signs of cervical spinal cord ...
