DEVELOPMENT AND EVALUATION OF A STANDARDIZED SYSTEM FOR THE ASSESSMENT OF LOCOMOTOR HEALTH IN ELEPHANTS UNDER HUMAN CARE.

Although lameness is a common problem in elephants (Asian elephant [Elephas maximus] and African elephants Loxodonta africana and Loxodonta cyclotis) under human care, there has not been a standardized lameness assessment system to date. This study developed and evaluated a standardized system for the assessment of locomotion in elephants under human care regardless of husbandry system. In total, 72 elephants out of a possible 73 in the United Kingdom and Ireland were filmed from behind, from in front, and from both sides. Using a questionnaire and a select panel of elephant specialists, a zoo veterinarian, and a locomotion expert, a numerical rating scoring (NRS) system was proposed. Locomotion was scored on a 4-point scale with numerical values 0-4 corresponding to specific criteria as follows: 0 = clinically sound, 1 = stiffness, 2 = abnormal tracking, and 4 = reluctance to bear weight. The intra- and interobserver repeatability of five veterinary surgeons using this system was determined and compared with a visual analog scale (VAS) expressed as a 100-mm line. Overall intraobserver reliability was moderate (Cohen's kappa [κ] = 0.676) and interobserver reliability was fair (κ = 0.37) for the presence of lameness. Interobserver agreement improved from the first scoring to second scoring from slight agreement to fair agreement for stiffness and reluctance to bear weight. Abnormal tracking had moderate intraobserver agreement for both scoring sessions. There were wide widths of agreement for the VAS interobserver (67 mm); however, they were narrower for the intraobserver (33 mm). The developed NRS can be used on freely moving elephants to evaluate elephant locomotion, regardless of husbandry methods, and has been shown to be more reliable than a VAS.

Faculty's Perception of a Research Project Embedded in the Undergraduate Veterinary Curriculum.

In this article, we describe faculty's perception of a research project embedded in the final year of the undergraduate veterinary curriculum and look at factors associated with overall perceptions of the project. We hypothesized that faculty would have a dichotomous attitude toward the research project, with faculty viewing it either positively or negatively, and that this opinion of the project would be largely influenced by the background of the faculty member-in particular, her or his role at the Royal Veterinary College. We explored this hypothesis via a questionnaire consisting of 26 questions in categorical format, Likert-scale format, and ranking format. The questions addressed faculty demographics, faculty's perceptions of the project, and generic skills. Faculty had an overall positive view of the project and found it to be a useful part of the undergraduate curriculum (83.3% found it to be useful or very useful). Faculty's perception of the project was influenced by their role at the college (p = .017), the species with which they primarily work (p = .05), and their opinion on the time spent supervising the final-year project (p = .003). We concluded that faculty view research as an important and useful part of the undergraduate veterinary curriculum.

Computed tomographic dimensions of the normal adult equine eye.

There are limited data on whether the dimensions of the equine eye and its internal structures change with bodyweight in horses. The aim of this study was to identify whether the size of the equine eye and its individual structures varied in a predictable manner with bodyweight, and to examine the reliability of computed tomography (CT) scans in the measurement of the equine eye. Ninety horses which had undergone CT examination of the head for non-ocular disease were included. All measurements of the eye were performed twice on all eyes by the same operator to quantify intra-operator agreement, and in 10 cases were also performed by a second operator to quantify inter-operator agreement. Agreement was excellent for all but the rostrocaudal measurement of the anterior chamber, which was fair. The following variables correlated significantly with bodyweight: anterior-posterior size of the globe (correlation coefficient: 0.586) and posterior segment (correlation coefficient: 0.554); the latero-medial size of the globe (correlation coefficient: 0.452), anterior chamber (correlation coefficient: 0.504) and posterior segment (correlation coefficient: 0.455); and the orbital fossa diameter (correlation coefficient: 0.219). The lens size and anterior-posterior distance of the anterior chamber did not correlate significantly with bodyweight. These results suggest that overall eye size and the size of the orbital fossa change with the bodyweight of the horse, but lens size remains consistent, and that CT measurements of the internal structures of the eye are repeatable and reproducible. This information aids in interventional procedures for ocular pathology and assessment of normal anatomy.

NEUROLOGIC AND COMPUTED TOMOGRAPHY FINDINGS IN SEA TURTLES WITH HISTORY OF TRAUMATIC INJURY.

Boat strikes have been widely documented as a major cause of anthropogenic trauma and mortality in sea turtles. Axial trauma in these species involves the head and/or carapace and may cause severe damage to the nervous and pulmonary systems. The aims of this study were to develop an updated protocol for neurologic examinations in sea turtles, to describe computed tomography (CT) findings in sea turtles with sustained trauma, and to associate CT findings with neurologic status in sea turtles with and without traumatic injury. Ten sea turtles were examined, six green (Chelonia mydas) and four loggerhead (Caretta caretta) turtles: seven underwent neurologic and CT examinations, two had CT examinations only, and one had a neurologic examination only. The updated neurologic examination protocol was considered useful in differentiating normal from abnormal neurologic status, however some of these tests remain unreliable in sea turtles. Sea turtles with no history of trauma were found to have normal carapace shape, vertebral column, and neurologic status. Sea turtles with history of traumatic injury (more than 10 years prior to examination) had findings dependent on trauma site. Those with head trauma had variable presentations dependent on location of injury; while those with carapace trauma had varying degrees of kyphosis, lordosis, and scoliosis of the carapace, vertebral fractures, and paraparesis. Kyphosis of the carapace was associated with vertebral fractures detected on CT; however, the severity of vertebral abnormalities was not associated with the severity of neurologic deficits. These findings suggest that a combination of neurologic and CT examination may be beneficial in determining clinical significance of carapace deformation and associated neurologic deficits in sea turtles with traumatic injury.

IMAGING DIAGNOSIS-THE COMPUTED TOMOGRAPHIC APPEARANCE OF A GIANT CELL TUMOR AFFECTING THE MANDIBLE IN A PYGMY GOAT.

A 3-year-old male neutered pygmy goat presented for evaluation of a progressive mandibular swelling and inappetence. A computed tomographic (CT) scan of the head and thorax was performed under general anesthesia. Computed tomography revealed an extensive multiloculated, markedly expansile lesion within the right hemimandible, which involved the articular surface of the temporomandibular joint. The goat was euthanased due to a poor prognosis and postmortem examination confirmed the diagnostic imaging findings. Histopathology was strongly suggestive of a multinucleated giant cell tumor, therefore this condition should be considered as a differential diagnosis in goats presenting with expansile mandibular mass lesions.

COMPUTED TOMOGRAPHIC APPEARANCE OF MELANOMAS IN THE EQUINE HEAD: 13 CASES.

Melanomas are one of the most common neoplasms in the horse and are frequently found in the head region. There is a genetic predisposition in horses with a gray hair coat. Computed tomography (CT) is frequently used in referral practice to evaluate the equine head but there are few reports describing the CT appearance of melanomas in this location. The aim of this retrospective, case series study was to describe characteristics in a group of horses with confirmed disease. Case records from two referral hospitals were reviewed, and 13 horses were identified that had undergone CT of the head, with a diagnosis of melanoma based on cytology, histopathology, or visual assessment of black (melanotic) tissue. A median of 11 melanomas was identified per horse (range 3-60), with a total of 216 masses. Melanomas were found most frequently in the parotid salivary gland, guttural pouches, surrounding the larynx and pharynx and adjacent to the hyoid apparatus. In noncontrast CT images, all melanomas were hyperattenuating (median; 113.5 Hounsfield units (HU), IQR; 26 HU) compared to masseter musculature (median; 69 HU, IQR; 5.5 HU). Fifty-six (25.9%) masses were partially mineralized and 41 (19.4%) included hypoattenuating areas. Histopathological assessment of these melanomas suggested that the hyperattenuation identified was most likely a result of abundant intracytoplasmic melanin pigment. Melanomas of the equine head appeared to have consistent CT features that aided detection of mass lesions and their distribution, although histopathological analysis or visual confirmation should still be obtained for definitive diagnosis.

Radiographic protocol and normal anatomy of the hind feet in the white rhinoceros (Ceratotherium simum).

Foot pathology is a common and important health concern in captive rhinoceroses worldwide, but osteopathologies are rarely diagnosed, partly because of a lack of radiographic protocols. Here, we aimed to develop the first radiographic protocol for rhinoceros feet and describe the radiographic anatomy of the white rhinoceros (Ceratotherium simum) hind foot (pes). Computed tomographic images were obtained of nine cadaver pedes from seven different white rhinoceroses and assessed for pathology. A single foot deemed free of pathology was radiographed using a range of different projections and exposures to determine the best protocol. 3D models were produced from the CT images and were displayed with the real radiographs to describe the normal radiographic anatomy of the white rhinoceros pes. An optimal radiographic projection was determined for each bone in the rhinoceros pes focusing on highlighting areas where pathology has been previously described. The projections deemed to be most useful were D60Pr-PlDiO (digit III), D45Pr45M-PlDiLO (digit II), and D40Pr35L-PlDiLO (digit IV). The primary beam was centered 5-7 cm proximal to the cuticle on the digit of interest. Articular surfaces, ridges, grooves, tubercles, processes and fossae were identified. The radiographic protocol we have developed along with the normal radiographic anatomy we have described will allow for more accessible and effective diagnosis of white rhinoceros foot osteopathologies.

Leap and strike kinetics of an acoustically 'hunting' barn owl (Tyto alba).

Barn owls are effective hunters of small rodents. One hunting technique is a leap from the ground followed by a brief flight and a plummeting 'strike' onto an acoustically targeted - and potentially entirely hidden - prey. We used forceplate measurements to derive kinetics of the leap and strike. Leaping performance was similar to reported values for guinea fowl. This is likely achieved despite the owl's considerably smaller size because of its relatively long legs and use of wing upstroke. Strikes appear deliberately forceful: impulses could have been spread over larger periods during greater deflections of the centre of mass, as observed in leaping and an alighting landing measurement. The strike, despite forces around 150 times that of a mouse body weight, is not thought to be crucial to the kill; rather, forceful strikes may function primarily to enable rapid penetration of leaf litter or snow cover, allowing grasping of hidden prey.

Design and validation of a computer-aided learning program to enhance students' ability to recognize lameness in the horse.

The ability to recognize lameness in the horse is an important skill for veterinary graduates; however, opportunities to develop this skill at the undergraduate level are limited. Computer-aided learning programs (CALs) have been successful in supplementing practical skills teaching. The aim of this study was to design and validate a CAL for the teaching of equine lameness recognition (CAL1). A control CAL was designed to simulate learning by experience (CAL2). Student volunteers were randomly assigned to either CAL and tested to establish their current ability to recognize lameness. Retesting occurred both immediately following exposure and 1 week later. At each test point, the number of correct responses for forelimb and hind limb cases was determined. Student confidence was assessed before and after CAL exposure, with previous opportunities to recognize lameness taken into account. Immediately following exposure, the number of correct responses was significantly higher for CAL1 than for CAL2, both overall and for forelimb cases but not for hind limb cases. After 1 week, the CAL1 group performed significantly better overall compared to the CAL2 group, with no significant difference between forelimb and hind limb cases. Student confidence and ability to recognize lameness were significantly improved following exposure to CAL1. When considered as one category, students in years 4 and 5 performed significantly better than year 3 students. Gender did not significantly affect performance. CAL1 could be used to supplement current lameness recognition opportunities. CAL1 is, however, limited in its ability to improve lameness recognition, especially in relation to hind limb lameness where it was unable to attain a significant difference from CAL2.

Factors influencing clinical students' perceptions of an embedded research project and associated publication output.

In this article, we describe student perceptions of the value of a short, compulsory research project embedded in a clinical degree program, the research output in terms of publications, and the factors influencing this. It was hypothesized that student attitudes toward the project, student perceptions of how much the project contributed to their generic skills, and the number of publications submitted or prepared for submission would be associated with perceived quality of supervision, perceived difficulty of the project, career plans, and attitude before commencement of the project. We explored this using a questionnaire comprising 30 questions that included demographics, Likert scales, and categorical responses. Student attitudes toward research were found to be associated with student attitude before the start of the project, perceived difficulty of the project, perceived quality of supervision, and perceived relevance to the profession. Students thought that the research project contributed most to the skills of "information gathering" and "critical evaluation" and the least to "teamwork," "problem solving," and "oral communication." Research output was significantly linked to perceived quality of supervision and the help students received with data analysis and data collection, though not with the project report itself. In conclusion, although the success of the research project was influenced by many factors, the perceived quality of supervision influenced all three outcome measures. Therefore it is clear that optimization of this aspect offers the most scope for enhancing the student learning experience.

Design and validation of a simulator for equine joint injections.

Joint injections are commonly used in equine practice for diagnosis and treatment of joint disorders. Performing joint injections is hence an essential skill for equine practitioners. However, opportunities for veterinary students to practice this skill are often scarce in veterinary curricula. The aim of this study was to design and validate an equine joint injection simulator. We hypothesized that the simulator will enhance student ability and confidence in performing joint injections. The simulator was constructed around an equine forelimb skeleton with soft tissues rebuilt using building foam and rubber bands. An electrical circuit including a buzzer, a battery, wire wool in the joints, and a hypodermic needle at the end of the cable was incorporated. If the students placed the needle into the joint correctly, instant auditory feedback was provided by the buzzer. To validate the simulator, 45 veterinary students were allocated to three groups: cadaver limb, textbook, or simulator. Students' ability to perform joint injections was tested and students' opinions were evaluated with a questionnaire. The proportion of students performing a metacarpophalangeal (MCP) joint injection correctly was significantly higher in the cadaver (93%) and simulator (76%) groups compared to the textbook group (50%). There was no significant difference between groups for performing a distal interphalangeal (DIP) joint injection correctly. Students rated the learning experience with the cadaver and simulator group high and with the textbook group low. The joint injection simulator represents an affordable teaching aid that allows students to repeatedly practice this skill in their own time with immediate feedback.

Osteopathology in the feet of rhinoceroses: lesion type and distribution.

An estimated 1,170 white (Ceratotherium simum), black (Diceros bicornis), greater one-horned (Rhinoceros unicornis), and Sumatran (Dicerorhinus sumatrensis) rhinoceroses are kept in captivity worldwide, where they are a popular public attraction and serve important roles in education and conservation. Rhinoceroses in captivity are reportedly affected by a variety of foot conditions, including abscesses, nail cracking, and pododermatitis, but there are few studies reporting associated bony pathology in these species. This study aimed to describe osteopathology in rhinoceros feet and identify normal and abnormal osteologic features of rhinoceros feet. The metacarpal-tarsal and phalangeal bones from 81 feet (67 skeletal specimens and 14 cadaveric feet), derived from 27 rhinoceroses of various species, were evaluated in the study (1 black, 11 white, 2 greater one-horned, 3 Javan, 9 Sumatran, and 1 unknown). Bones were examined visually (skeletal specimens) or by computed tomography (cadaver specimens) for evidence of bony lesions. Of the 27 rhinoceroses examined, 22 showed some degree of bone pathology in at least one limb. Six broad categories of pathologic change were identified, with numbers in parentheses representing numbers of rhinoceroses with lesions in at least one limb/number of rhinoceroses examined: enthesopathy (20/27), osteoarthritis (15/27), pathologic bone remodeling (12/27), osteitis-osteomyelitis (3/27), fracture (3/8), and subluxation (3/8). The frequency of pathologic changes in fore- and hind limbs was not significantly different. Most (91%) enthesopathies were observed on the proximal phalanges of the digits, and osteoarthritis was most common in the distal interphalangeal joints of the medial and lateral digits (32 and 26%, respectively). In addition to the pathology described, all examined rhinoceroses also had multiple small surface lucencies in the distal limb bones as an apparently normal anatomic feature. This study is an important first step in identifying both normal and pathologic features of rhinoceros feet and hopefully will thereby contribute to the improved knowledge and care of these species.

Survey investigating factors affecting recruitment and retention in the UK veterinary nursing profession.

BACKGROUND: Recruitment and retention have been identified as contributing factors to workforce shortages in the veterinary team. METHODS: Results from veterinary nurses to an online questionnaire regarding recruitment and retention were analysed. RESULTS: Veterinary nurses had few job changes (median 2); however, 53.8% (n = 1060) reported they were likely or very likely to leave their employment within 2 years. Respondents who were recently qualified (p < 0.001) and on lower salaries (p < 0.001) were significantly more likely to plan to leave. The most frequently chosen reasons to stay in a position were team, location and working hours, while reasons to leave were salary, management and work-life balance. Respondents most disliked 'dealing with people', remuneration and work-life balance and would like to change the salary, management and team aspects. Employers reported difficulty in employing an experienced veterinary nurse. LIMITATIONS: A questionnaire simplifies the nature of retention. Also, a comparatively low number of responses was received, with overrepresentation of some groups. It was conducted in 2018; however, it still provides a useful comparison for studies regarding recent world events. CONCLUSION: The shortage of veterinary nurses is due in part to the lack of retention within the profession. Adequate recompense for work undertaken and value attributed to the role are suggested as contributing factors.

Effects of sand, asphalt and 3-degree hind toe or heel elevation on horse kinematics.

BACKGROUND: Although the effects of both the surfaces and plantar angles on equine locomotion have been widely discussed, limited scientific data are available. METHODS: Our objectives were to determine the effects of two surfaces (asphalt and sand) and of 3-degree hind toe or heel elevation on horse kinematics in an experimental study. Six saddle horses were shod with a reference shoeing (REF), characterized by a fore aluminium (REF F) and hind steel racehorse (REF H) shoeing. Two dimensional kinematic videos compared horse's kinematic parameters when walking and trotting on asphalt and sand. On asphalt, REF was also compared with REF F and a modified REF H with additional 3-degree hind-toe or -heel wedges. RESULTS: On asphalt versus sand, horses had, at the trot, a shorter stride duration and forelimb maximal retraction, and at walk and trot, a greater fetlock, carpus, elbow and tarsus extension, a greater fore and hind limbs maximal protraction and a shorter hind limbs maximal retraction. Increasing the plantar angle decreased the tarsus and hind fetlock extension, in contrast to fore-limb, on asphalt during the stance phase. CONCLUSIONS: These findings could be useful to adapt rehabilitation programs related to fore and hind limb pathologies, at slow gaits.

Three-dimensional biomechanics of simulated laryngeal abduction in horses.

OBJECTIVE: To investigate the influence of simulated contraction of the cricoarytenoideus dorsalis (CAD) muscle on the 3-D motion of the arytenoid cartilage. SAMPLE POPULATION: 5 larynges from equine cadavers. PROCEDURES: Serial computed tomographic scans of each larynx were conducted at 7 incremental forces simulating contraction of medial, lateral, and combined bellies of the left CAD muscle. Three-dimensional reconstruction of radiopaque markers placed at anatomic landmarks on the left arytenoid and cricoid cartilages enabled quantification of marker displacement according to a Cartesian coordinate system. Rotation (roll, pitch, and yaw) of dorsal and ventral arytenoid planes was calculated relative to a plane formed by the coordinates of 3 markers on the cricoid cartilage by use of Euler angles. RESULTS: Displacement and rotational data showed that rocking motion occurs throughout arytenoid abduction and most of the rotational component is attributable to pitch; greater pitch was associated with action of the lateral belly. Roll of the ventral arytenoid plane was principally associated with action of the medial belly, which counteracted the tendency of the arytenoid cartilage to rotate medially into the rima glottidis lumen. The distance between markers on the arytenoid cartilage was not constant during contraction because of slight deformation of the corniculate process of the arytenoid cartilage, therefore indicating that the arytenoid cartilage is not a rigid body during abduction. CONCLUSIONS AND CLINICAL RELEVANCE: Arytenoid cartilage abduction was dependent on the rocking motion elicited by the lateral belly of the CAD muscle; therefore, laryngoplasty suture placement should mimic the action of the lateral, rather than the medial, muscle belly.

Women in veterinary leadership positions: their motivations and enablers.

BACKGROUND: Despite now having higher numbers of women than men within the veterinary profession, there are substantially less women in leadership roles. Research, primarily in other professions, has focussed on barriers to leadership and sometimes overlooked facilitators and motivators. This study aimed to explore the motivating factors for female veterinary surgeons to become leaders, to identify potential strategies to increase female leadership. METHODS: Sixteen female leaders from academia, professional bodies, industry and clinical practice took part in semistructured interviews. Interviews were analysed using a thematic analysis approach. RESULTS: Two themes were developed: 'Potential for positive influence' and 'Requirement of external enablers'. Participants wanted to influence change for themselves, including work-life balance and developing their role, and for others through a position of influence. They wanted to inspire and mentor the future generation of leaders. External enablers allowed this transition to occur, including formal mentors and informal support systems, opportunities for growth and increased responsibility, and leadership training. CONCLUSION: Potential strategies to increase female leaders include the promotion of female role models, increasing awareness of training and increasing work flexibility. The profession could improve its support of the next generation of leaders and celebrate the successful female leaders we already possess.

Investigation of factors affecting recruitment and retention in the UK veterinary profession.

BACKGROUND: Recruitment and retention is currently of major concern and has resulted in the veterinary profession being returned to the UK's Shortage Occupation List in 2019. METHODS: An online questionnaire of veterinary employees and employers investigating factors contributing to leaving/staying in current employment and the profession. The questionnaire was distributed via specialist veterinary associations' email lists and social media from September to October 2018. RESULTS: Respondents had few job changes (median 3), however, 43.7 per cent (n=2390) reported that they were likely or very likely to leave their employment within two years. Vets who were recently qualified, on lower salaries and female were more likely to plan to leave. Most frequently chosen reasons to stay in a position were: team, location and family. Most commonly cited reasons to leave were: work-life balance, management and salary. Respondents most disliked dealing with people, work-life balance and the physical/emotional impacts of the job. They would most like to change the hours worked, team aspects and management. Employers suggested that it was difficult to employ a veterinary surgeon, especially an experienced individual. CONCLUSION: The current retention crisis is due in part to the differing requirements between modern-day veterinary employees, their employers, the public and the profession.

The Effect of Tungsten Road Nails on Upper Body Movement Asymmetry in Horses Trotting on Tarmac.

Tungsten road nails are commonly used by farriers to increase grip between the hoof and the ground surface. There is limited evidence relating the use of road nails to the fundamental mechanics of movement. Grip is important for efficient deceleration on landing and subsequent propulsion, but this must be balanced against an amount of slip to divide the landing force into horizontal as well as vertical subcomponents. Here, we conducted an intervention study to quantify the effect of lateral heel road nail placement on weight bearing and propulsion in 10 horses trotting on tarmac. Wireless inertial measurement units measured vertical movement asymmetry. Differences in head and pelvic movement asymmetry before/after subsequent application of laterally placed road nails to forelimb and hindlimb hooves in a randomized order were compared to zero value (no change) with a one-sample t-test, P < .05. Left-to-right tuber coxae movement amplitude difference was significantly more negative (-3.25 mm, P = .03), suggesting more right than left tuber coxae movement amplitude, after application of a road nail to the left hindlimb. No movement asymmetries at the poll, withers, or sacrum were detected after nail placement (all P > .055). Pelvic movement indicates a very small increase in weight bearing and propulsion provided by the hindlimb with a laterally placed road nail compared to the contralateral hindlimb. Further work is needed to investigate slip- and grip-related parameters at the level of the hoof and to investigate the long-term consequences of very small changes in movement asymmetry.

The effect of curve running on distal limb kinematics in the Thoroughbred racehorse.

During racing, injury is more likely to occur on a bend than on a straight segment of track. This study aimed to quantify the effects of galloping at training speeds on large radius curves on stride parameters and limb lean angle in order to assess estimated consequences for limb loading. Seven Thoroughbred horses were equipped with a sacrum-mounted inertial measurement unit with an integrated GPS, two hoof-mounted accelerometers and retro-reflective markers on the forelimbs. Horses galloped 2-4 circuits anticlockwise around an oval track and were filmed at 120 frames per second using an array of ten cameras. Speed and curve radius were derived from GPS data and used to estimate the centripetal acceleration necessary to navigate the curve. Stride, stance and swing durations and duty factor (DF) were derived from accelerometer data. Limb markers were tracked and whole limb and third metacarpus (MCIII) angles were calculated. Data were analysed using mixed effects models with a significance level of p < 0.05. For horses galloping on the correct lead, DF was higher for the inside (lead) leg on the straight and on the curve. For horses galloping on the incorrect lead, there was no difference in DF between inside and outside legs on the straight or on the curve. DF decreased by 0.61% of DF with each 1 m s-2 increase in centripetal acceleration (p < 0.001). Whole limb inclination angle increased by 1.5° per 1 m s-1 increase in speed (p = 0.002). Limb lean angles increase as predicted, and lead limb function mirrors the functional requirements for curve running. A more comprehensive understanding of the effects of lean and torque on the distal limb is required to understand injury mechanisms.

Computed Tomographic Evaluation of Adjacent Segment Motion after Ex Vivo Fusion of Equine Third and Fourth Cervical Vertebrae.

OBJECTIVE: Surgical fusion of vertebral segments is a treatment option for horses with cervical stenotic myelopathy or cervical fracture.Degenerative disease affecting adjacent vertebral segments is a reported complication following surgical vertebral fusion in other species, termed adjacent segment disease. The aim of this study was to evaluate the impact of cervical vertebral fusion on the biomechanics of adjacent vertebral segments in the horse. STUDY DESIGN: Neck specimens of 12 horses were assessed using computed tomographic imaging. Range of motion (ROM) was determined by measuring the maximum sagittal flexion, extension and lateral bending between C2 and C5. C3/4 was subsequently fused using a standard locking compression plate and locking head screws and computed tomographic scans and ROM measurements were repeated. RESULTS: Prior to intervertebral fusion, a significant increase in ROM along the vertebral segments from cranial to caudal was observed. Range of motion measurements of C3/4 decreased significantly after fusion (p = 0.01).Range of motion of the adjacent segments (C2/3 and C4/5) did not change significantly after fusion. CONCLUSION: Fusion of one cervical intervertebral joint did not affect the ROM of the adjacent vertebral segments. Further research investigating the implications of vertebral fusion on the intervertebral pressure in the equine patient is indicated.