Hindlimb Lameness Research Articles

Molecular characteristics and pathogenicity of an equid alphaherpesvirus 1 strain isolated in China.

Equid alphaherpesvirus 1 (EHV-1) is prevalent in China, and causes notable economic damage to the equine industry. However, there is no information regarding the molecular characteristics and pathogenicity of the Chinese strains. Therefore, an EHV-1 strain, named YM2019, was isolated from the lung tissue of an aborted horse fetus in Xinjiang, China, and its genome and pathogenicity were analyzed. The full genome of the isolate was 150,267 base pairs in length, with 56.7% G + C content. Genetic and phylogenetic analysis showed that strain YM2019 (GenBank: MT063054) belonged to the ORF30 N752 genotype but displayed a high level of similarity with strain Ab4 (ORF30 D752, GenBank: AY665713) isolated in Britain. Fourteen unique amino acid mutations were found when comparing strain YM2019 with the reference strains Ab4 and V592 (ORF30 N752, GenBank: AY464052). Syrian hamsters infected with strain YM2019 exhibited severe respiratory and neurological clinical signs and died. Infection with strain YM2019 in Yili horses caused rhinopneumonitis, viremia, and neurological clinical signs such as hind limb lameness, prostration, and reduced movement. Here, we describe the features of an EHV-1 strain discovered in China, together with the complete genome sequence, and reveal that a nonneurovirulent strain (ORF30 N752) can also cause neurological signs in horses. The data will be useful in providing some reference for further research into the relationship between viral genotypes and pathogenicity.

Modelling fore- and hindlimb peak vertical force differences in trotting horses using upper body kinematic asymmetry variables

Differences in peak vertical ground reaction forces (dFzpeak) between contralateral forelimbs and hindlimbs are considered the gold standard for quantifying weight-bearing lameness. However, measuring kinematics for the same purpose is more common and practical. Vertical movement asymmetries (VMA) of the horse’s upper body have previously been correlated to fore- and hindlimb lameness. But the combined response of head, withers and pelvis VMA to fore- and hindlimb dFzpeak has not yet been thoroughly investigated. Deriving the kinetic responses from kinematics would help the interpretation and understanding of quantified weight-bearing lameness.In this retrospective study, 103 horses with a wide range of fore- and hindlimb dFzpeak had been trotted on a force-measuring treadmill synchronized with an optical motion capture system. VMA of the head, withers and pelvis as well as dFzpeak were extracted. Multiple linear mixed models and linear regressions of kinematic variables were used to model the dFzpeak. It was hypothesised that all included VMA would have a significant influence on the dFzpeak outcome variables.The results showed a complex relationship between VMA and dFzpeak where both amplitude and timing of the VMA were of importance. On average, the contribution percentage of VMA to fore/hind dFzpeak were 66/34% for head, 76/24% for withers and 33/67% for pelvis. The linear regressions for the fore/hindlimb models achieved mean measurement root mean squared errors of 0.83%/0.82% dFzpeak. These results might help determine the clinical relevance of upper body VMA and distinguish between primary fore, hind, ipsilateral and diagonal weight-bearing lameness.

Severe chronic osteomyelitis of the os ileum in an alpaca - Diagnostic and pathological findings

A 5.5-year-old alpaca mare was referred to the University Clinic for Ruminants due to a lameness in the right hind limb. Six months prior to presentation, the mare had been treated with systemic antibiotics resulting in resolution of the initial lameness. At the time there had been no indication of an inciting trauma. Clinical examination revealed an approx. 2 × 2 cm large, fluctuating, neither excessively warm nor painful mass caudal to the right tuber coxae fixed to the underlying tissue. In addition, a moderate, mixed lameness with a predominant proportion of the swinging leg component was present in the right hind limb. Subsequently, sonographic examination of the right gluteal region was performed, revealing severe alterations of bone contour in the area of the right hip joint. Radiographic assessment of the pelvis was carried out for further clarification. Based on the clinical finding of a fistula in the right gluteal region as well as the results of the radiologic examination, a long-standing infected fracture of the right iliac bone accompanied by high-degree, irregularly calcified callus formation and low to moderate osteomyelitis in the fracture area was diagnosed. The patient was euthanized in consequence of the grave prognosis. Computed tomographic examination of the pelvis and the lumbar spine in the L3-L6 area was undertaken in order to further document the extent of the pathological changes. For final clarification, patho-histological examination as well as a microbiologic analysis of the abscess exudate were performed.The presented case shows the importance of clinical as well as orthopedic examinations, as the individual animal frequently only exhibits minimal clinical signs despite the presence of severe changes.

Clinical signs, diagnostic imaging and histopathology in a dog with granulomatous meningoencephalitis manifested as a polyneuropathy

AbstractAn 11‐year‐old, female, neutered Labrador retriever with a history of chronic and progressive right hindlimb lameness and facial asymmetry was referred for brain and lumbosacral magnetic resonance imaging and cerebrospinal fluid analysis. Multifocal non‐enhancing T2‐weighted images of hyperintense lesions were observed in the caudate nuclei and medulla oblongata. The right oculomotor nerve was markedly enlarged and showed marked enhancement on T1‐weighted images after contrast injection, and there was diffuse enlargement of the sciatic and femoral nerves in the right hindlimb. Cerebrospinal fluid analysis showed a mixed pleocytosis. Histopathology revealed granulomatous inflammation affecting the brain, oculomotor and pelvic limb nerves, consistent with a diagnosis of granulomatous meningoencephalomyelitis.

Antemortem diagnosis of a doubly committed juxta‐arterial ventricular septal defect resulting in bacterial endocarditis and septic arthritis in a Holstein heifer

AbstractA 20‐month‐old Holstein heifer presented for evaluation of progressive hindlimb lameness that was localised to the left coxo‐femoral joint, with development of a fever, tachycardia and bruxism. Radiographs and ultrasound of the coxo‐femoral joint were relatively unremarkable. An echocardiogram showed a static left‐to‐right shunting ventricular septal defect (initially diagnosed via echocardiogram 1 year prior) and a new filling defect within the pulmonary trunk suggestive of pulmonary valve endocarditis. Blood culture was positive for alpha‐haemolytic Streptococcus spp. Euthanasia was elected and postmortem examination confirmed ventricular septal defect, pulmonary valvular endocarditis, septic arthritis of the left coxo‐femoral joint and positive cultures for alpha‐haemolytic Streptococcus spp. This case describes endocarditis, bacteraemia and septic arthritis in a heifer with a ventricular septal defect. As with other species, cattle with ventricular septal defects should be considered susceptible and predisposed to complications such as endocarditis; this information may be useful for prognostication and management decisions.

Conservative treatment of an incomplete calcaneal fracture in a pony using a tarsal sleeve cast

SummaryA 9‐year‐old 390 kg games pony presented with acute onset of grade 5/5 (AAEP) right hindlimb (RH) lameness. During clinical examination, the source of lameness was localised to the tarsal region. Radiographic examination identified a closed, simple, nondisplaced, incomplete fracture of the calcaneal shaft. The pony was initially treated with box rest; however, despite an initial good response, the horse re‐presented with a grade 5/5 (AAEP) RH lameness, 2 weeks after initial presentation. The decision was made to treat the fracture using a tarsal sleeve cast extending from mid‐third of the tibia/crus to the level of distal metatarsus. The cast was replaced every 2 weeks and maintained for a total of 8 weeks. After cast removal, the horse was kept on strict box rest for 3 weeks. After discharge from the hospital, in‐hand walking exercise from the stable was commenced and gradually increased over a 4‐week period. The horse was then gradually reintroduced to small paddock turnout exercise for eight further weeks. The horse was able to return to full athletic function. Conservative treatment using a tarsal sleeve cast should be considered only in horses presenting an incomplete nondisplaced fracture of the calcaneal shaft.

Neoplastic transformation of arteriopathy‐derived bone infarct into nascent osteosarcoma in the proximal tibia of a miniature schnauzer

AbstractA 9‐year‐old, entire, male miniature schnauzer with a history of chronic right hindlimb lameness was presented to a referral orthopaedic surgery practice for acute non‐weight bearing and suspected cranial cruciate ligament rupture. Radiographs revealed polyostotic bone infarcts, characterised by stippled medullary densities, and an aggressive osteolytic infarct in the right proximal tibia. Histopathology of the amputated limb revealed an arteriopathy of the nutrient artery and a zonal histologic pattern of neoplastic transformation: at the infarct apex, mesenchymal stromal cells were engaged in repair. As the cells proliferated towards the centre of the infarct within an environment of chronic ischaemia, cell features became consistent with low‐grade sarcoma, then nascent (early) osteosarcoma. This zonal progression has been described in humans, but not in dogs. It is unknown whether nascent osteosarcoma has the same biologic activity as long‐standing osteosarcoma. Veterinarians should be aware of canine bone infarcts and their potential sequelae.

Visual lameness assessment in comparison to quantitative gait analysis data in horses.

Quantitative gait analysis offers objective information to support clinical decision-making during lameness workups including advantages in terms of documentation, communication, education, and avoidance of expectation bias. Nevertheless, hardly any data exist comparing outcome of subjective scoring with the output of objective gait analysis systems. To investigate between- and within-veterinarian agreement on primary lame limb and lameness grade, and to determine relationships between subjective lameness grade and quantitative data, focusing on differences between (1) veterinarians, (2) live vs video assessment, (3) baseline assessment vs assessment following diagnostic analgesia. Clinical observational study. Kinematic data were compared to subjective lameness assessment by clinicians with ≥8years of orthopaedic experience. Subjective assessments and kinematic data for baseline trot-ups and response to 48 diagnostic analgesia interventions in 23 cases were included. Between and within-veterinarian agreement was investigated using Cohen's Kappa (κ). Asymmetry parameters for kinematic data ('forelimb lame pattern', 'hindlimb lame pattern', 'overall symmetry', 'vector sum head', 'pelvic sum') were determined, and used as outcome variables in mixed models; explanatory variables were subjective lameness grade and its interaction with (1) veterinarian, (2) live or video evaluation and (3) baseline or diagnostic analgesia assessment. Agreement on lame limb between live and video assessment was 'good' between and within veterinarians (median κ=0.64 and κ=0.53). There was a positive correlation between subjective scoring and measured asymmetry. The relationship between lameness grade and objective asymmetry differed slightly between (1) veterinarians (for all combined parameters, p-values between P<.001 and 0.04), (2) between live and video assessments ('forelimb lame pattern', 'overall symmetry', both P≤.001), and (3) between baseline and diagnostic analgesia assessment (all combined parameters, between P<.001 and .007). Limited number of veterinarians (n=4) and cases (n=23), only straight-line soft surface data, different number of subjective assessments live vs from video. Overall, between- and within-veterinarian agreement on lame limb was 'good', whereas agreement on lameness grade was 'acceptable' to 'poor'. Quantitative data and subjective assessments correlated well, with minor though significant differences in the number of millimetres, equivalent to one lameness grade between veterinarians, and between assessment conditions. Differences between baseline assessment vs assessment following diagnostic analgesia suggest that addition of objective data can be beneficial to reduce expectation bias. The small differences between live and video assessments support the use of high-quality videos for documentation, communication, and education, thus, complementing objective gait analysis data.

Magnetic Resonance Imaging of the Dromedary Camel Stifle

The objective of the present investigation was to develop a high-field magnetic resonance imaging (MRI) protocol for assessment of the dromedary camel stifle region and to describe normal MRI appearance of the stifle by comparing MRI images with their corresponding anatomic slices. Twelve cadaveric hind limbs were obtained from 6 clinically sound adult dromedary camels without hind limb lameness. Cadaveric stifles were scanned by 1.5 Tesla MRI system using T1-weighted, T2-weighted, proton density gradient echo and short Tau inversion recovery sequences in 3 planes. After imaging, stifles were frozen at – 18°C for 2 weeks, then sectioned in sagittal, dorsal or transverse planes. Optimal MRI images from different sequences and planes were evaluated and correlated to their corresponding gross anatomic slices. Descriptive findings of the articular cartilage, subchondral bone, cruciate ligaments, menisci, menisco-tibial and menisco-femoral ligaments, long digital extensor tendon, and patellar ligament were reported. The high-field MRI protocol described in this study provided high spatial and contrast resolution of the osseous and soft tissue structures of the dromedary camel stifle joint. Data obtained in this study could be used as normal reference standards for evaluation of the dromedary camel stifle in clinical situations.

Biomechanical cyclic loading test of a synthetic ligament fixation system used for intra-articular stabilization of deficient canine stifles.

Background:Cranial cruciate ligament rupture (CCLr) is the most common cause of hind limb lameness in dogs. Currently, surgical management of CCLr is mostly performed using tibial osteotomy techniques to modify the biomechanical conformation of the affected stifle. These surgical techniques have a significant complication rate, associated with persistent instability of the stifle which may lead to chronic postoperative pain. Over the last decade, studies have been published on various techniques of anatomical caudal cruciate ligament reconstruction in veterinary practice, using physiological autografts or woven synthetic implants.Aim:The aim of this ex vivo biomechanical study is to investigate the ex vivo dynamic biomechanical behavior of a synthetic implant [ultrahigh molecular weight polyethylene (UHMWPE) implant] fixed with interference screws for the treatment of CCLr in dogs, according to a fatigue protocol (48 hours per test).Methods:Seven stifles from four skeletally mature canine cadavers were implanted with the synthetic implant. It was fixed with four interference screws inserted in transversal and oblique tunnels in both the distal femur and the proximal tibia. For each case, 100,000 cycles were performed at 0.58 Hz, with traction loads ranging from 100 to 210 N.Results:Neither screw-bone assembly rupture nor a pull-out issue was observed during the dynamic tests. Linear stiffness of the implants associated with a fixation system with four interference screws increased over time. The final displacement did not exceed 3 mm for five of the seven specimens. Five of the seven synthetic implants yielded to a lengthening in functional range (0–3 mm). Linear stiffness was homogeneous among samples, showing a strong dynamic strength of the interference screw-based fixations of the UHMWPE implant in the femoral and tibial bones.Conclusion:This study completes the existing literature on the biomechanical evaluation of passive stifle stabilization techniques with a testing protocol focused on cyclic loading at a given force level instead of driven by displacement. These biomechanical results should revive interest in intra-articular reconstruction after rupture of the CCLr in dogs.

Hematological, Biochemical, and Skeletal Muscle Metabolic Responses to Exercise Related Myopathy in Endurance Horses

Equine exertional rhabdomyolysis (ER) is a well-recognized disease affecting racehorses therefore this study was performed to evaluate haemato-biochemical alterations in 20 adult Arabian horses after 120 km race with trial of treatment. Horses were classified into 2 main groups: the first group (n:5) included healthy control horses while the second group(n:15) included horses showed signs of distress, moderately depressed, muscle stiffness, shifting hind limb lameness, elevated respiratory rate, sweating, firm painful hindquarter muscles, myoglobinuria and reluctance to move that lasts for several hours after ending of race. Based on the history and the through clinical examination of diseased horses, they were tentatively diagnosed as suffering from ER syndrome. Whole blood and serum samples were collected from both healthy control horses and diseased ones before and after treatment. Hemogram of examined horses showed only significant increased PCV (%) values of diseased horses with more prominent thrombocytopenia but with treatment their values showed marked improvement, where other haematological parameters showed non-significant changes in both groups either before or after treatment. Serum analysis of ER affected horses showed a higher serum enzymatic activities of creatine phosphokinase (CK) and aspartate aminotransferase (AST) with significantly increased values of total proteins, albumin, globulins, total bilirubin, glucose, creatinine and potassium. But with effective treatment protocol, these higher values began to be improved towards normal values again. While non-significant changes were observed in serum levels of Gamma-glutamyl transpeptidase (GGT), calcium, sodium and blood urea nitrogen (BUN) in ER affected horses. Based on obtained results, ER has negative impact on haemato-biochemical biomarkers with remarkable serum elevation of skeletal muscular specific enzymes, as well as by paralytic myoglobinuria.

Deep Digital Flexor Contracture following Combined Tibial Plateau Levelling Osteotomy and Cranial Closing Wedge Ostectomy: A Case Report in a Dog

AbstractThis case report describes the use of a Z-plasty tenotomy and anastomosis to surgically lengthen the deep digital flexor (DDF) tendons of digits 2 to 5 of the pelvic limb in a 6-year-old male castrated Greyhound. The procedure was used to treat contracture of this tendon complex which developed after a series of complications secondary to proximal osteotomies utilized for the treatment of cranial cruciate ligament rupture. The dog was evaluated for lameness associated with left cranial cruciate ligament rupture and excessive tibial plateau slope; accordingly, a combined tibial plateau levelling osteotomy and cranial closing wedge ostectomy was performed. Postoperatively, the dog developed substantial DDF tendon contracture that led to severe digital hyperflexion and contributed to a non-weight bearing lameness. The dog received intensive rehabilitation therapy but failed to substantially improve; therefore, all of the weight-bearing left hindlimb DDF tendons were lengthened with a Z-plasty tenotomy and anastomosis followed by further rehabilitation. Follow-up evaluation 44 months postoperatively documented mild, intermittent left hindlimb lameness on gait observation and confirmed success of the Z-plasty procedure via ultrasonographic evaluation. Conservative treatment alone was unsuccessful in managing DDF tendon contracture in this dog. Z-plasty tenotomy and anastomosis of the DDF tendon allowed for return-to-acceptable function in this case.

Canine Intrapelvic Hemangiosarcoma in 12 Dogs (2000–2019): a Retrospective Case Series

ABSTRACT Intrapelvic hemangiosarcoma (IP HSA) is an uncommon primary location of canine HSA, and its presentation appears to be different than that of other intra-abdominal HSA locations. The objectives of this study were to report on the clinical presentation, diagnostic options, and clinical outcomes of dogs with IP HSA. Medical records from two veterinary teaching hospitals between 2000 and 2019 were reviewed for dogs diagnosed with IP HSA. Inclusion criteria consisted of a cytologic or histopathologic diagnosis of HSA from a mass arising from the muscles of the pelvic canal. Exclusion criteria included masses arising from organs within the pelvic canal, including the urethra, prostate, and urinary bladder. Twelve dogs were ultimately included in the study. Clinical presentation of IP HSA was varied, with clinical signs including hindlimb lameness, urethral obstruction, and evidence of hemoperitoneum. The median progression free survival was 92 days (range: 1–1057 days). The overall survival time was 165 days (range: 1–1170 days). IP HSA is an underreported location of canine HSA with similar biologic behavior and outcome compared with visceral HSA. It serves as an important differential in patients presenting with new-onset lameness and urethral obstruction.

Haematogenous synovial sepsis of the digital flexor tendon sheath following contralateral limb foot abscessation in a horse

AbstractA 5‐year‐old Shire mare was presented for investigation of severe right hindlimb lameness and was diagnosed with extensive right hind subsolar and submural foot abscessation. The mare developed severe contralateral limb lameness 11 days following right hind abscess debridement, with investigation revealing synovial sepsis of the left hind digital flexor tendon sheath. Synovial sepsis persisted despite aggressive surgical and medical treatment, resulting in euthanasia. Microbial culture of synovial fluid isolated Bacteroides sp., consistent with haematogenous synovial sepsis. This is the first report to describe haematogenous synovial sepsis as a cause of contralateral limb lameness during the management of foot abscessation in the horse.

Robustness of five different visual assessment methods for the evaluation of hindlimb lameness based on tubera coxarum movement in horses at the trot on a straight line.

The evaluation of hindlimb lameness remains a major challenge in everyday clinical practice. In the absence of clear guidelines, veterinarians use different visual assessment methods for this task whose robustness is unknown. Determination of the robustness of five visual hindlimb lameness assessment methods based on the comparison of left and right tuber coxae movement. Validated mathematical hindlimb lameness model based on experimental data from the literature. Vertical movement of left (LTC) and right (RTC) tuber coxae was simulated for the range of common hindlimb lameness movement patterns that horses present within practice. Lameness severity ranged from sound to moderately lame (0% to 60% motion asymmetry). The scenarios of a pelvis held tilted and asymmetrical pelvic roll were included to reflect possible adaptations in pelvic rotation. Across all conditions, the outcomes for five different visual assessment methods based on comparative tubera coxarum movement were quantified, including hip hike, -drop and range of motion. The robustness of each assessment method was established through comparison to sacrum-based overall motion asymmetry as the ground truth. Tubera coxarum-based lameness assessment was highly sensitive to all the unique lameness patterns and changes in pelvic rotation which a lame horse may adopt. None of the five visual lameness assessment methods was 100% robust across all conditions tested. For everyday clinical practice, comparing the upward movement amplitude of the RTC before right hind foot contact and of the LTC before left hind foot contact (Hip_hike_diff) would be the most robust single tubera coxarum-based visual assessment method. In the absence of published data regarding the frequency of different movement patterns and hip rotation adaptations in clinical practice, this study cannot indicate the proportion of assessments that would be incorrect for a given visual assessment method. Using a single tubera coxarum-based visual hindlimb lameness assessment method may lead to incorrect clinical judgement. Therefore, using multiple assessment methods would be beneficial to substantiate impressions.

Mid-to-caudal partial hemipelvectomy with limb preservation for ischial tumor in a dog.

A 10-year-old spayed female Golden Retriever was referred for hindlimb lameness. A firm mass was palpated over the right caudal pelvis. Computed tomography revealed an osteolytic bone region and an associated periosteal reaction in the ischium, including the acetabulum. The histological diagnosis was sarcoma of unknown origin. A mid-to-caudal partial hemipelvectomy was performed to remove the mass. Femoral head and neck osteotomy was performed to allow hindlimb preservation. Following surgery, the dog regained satisfactory hindlimb use over time and was alive for 821 days with no recurrence or metastatic disease. This report indicates that mid-to-caudal partial hemipelvectomy with femoral head and neck osteotomy is technically feasible and allows for tumor control with preservation of the hindlimb and its function.

Arthroscopic treatment of bilateral mandibular condylar cysts and associated osteoarthritis of the temporomandibular joints in a horse

SummaryA horse was presented with a history of unpredictable behaviour under saddle to the point that the owner deemed the horse dangerous to ride. In addition, at rest the horse frequently protruded his tongue and during mastication a “clunking” sound could be heard. Radiographic examination at a previous clinic had revealed a normal left temporomandibular joint (TMJ) and a radiopaque mass in the right TMJ. However, despite arthroscopic surgery of the abnormal joint, the clinical signs had not resolved. Diagnostic investigation at the referral clinic revealed that TMJ analgaesia altered both a baseline hindlimb lameness and a behavioural component to the movement of the horse. Computed tomography (CT) illustrated the presence of bone cysts within the mandibular condyles and marginal osteophytosis of the discomandibular joints consistent with osteoarthritis. Arthroscopic examination, debridement of the affected joints and post‐operative intra‐articular injection of autologous protein solution resulted in temporary resolution of both the behavioural changes and the “clunking” sound. Ultimately, the horse was euthanised for continued dangerous behaviour, which treatment had failed to resolve in the longer term. In conclusion, the presence of cysts in the mandibular condyle and osteoarthritis can be a cause of abnormal behaviour, which may render a horse dangerous to ride. The case report illustrates the complex interaction between the TMJ, behaviour and movement.

English

An 8-day-old female Shetland pony was referred to the Jeonbuk animal medical center for evaluation of bilateral hindlimb lameness. The foal had been severely lame in the both hind leg since birth. The luxation of the patella was confirmed on physical examinations. During the operation, extensive soft tissue damage and hemorrhage were observed around the medial patellar ligament. Lateral patellar luxation was surgically repaired using lateral release of the patella and medial imbrication of the joint capsule. Follow up revealed that lameness improved during postoperative period. It was concluded that patella luxation as a traumatic cause of lameness in foals can be corrected by surgical techniques successfully. Key words: Lateral patellar luxation, surgery, shetland pony, foal, stifle.

Compensatory Changes in Ground Reaction Forces in Small and Large Breed Dogs with Unilateral Hindlimb Lameness in Comparison to Healthy Dogs

The aim of this study was to investigate whether small- to medium-sized dogs with a naturally occurring unilateral hindlimb lameness show the same compensatory changes in ground reaction forces as large-breed dogs and how the changes are displayed compared with healthy small- to medium-sized dogs. Small- to medium-sized dogs (n = 15) and large-breed dogs (n = 16) with unilateral rupture of the cranial cruciate ligament were examined. The kinetic parameters peak vertical force and vertical impulse of the two groups were compared with each other and compared with healthy Beagles (n = 15) and with healthy Labrador Retrievers (n = 17), respectively. The healthy Beagle group showed a significantly higher weight loading on the forelimbs compared with the healthy Labrador group. The affected groups in comparison with the corresponding healthy groups showed a higher load on the non-affected body half and a significant lower weight bearing on the affected limb. Comparing the two affected groups, no significant difference could be found. Despite a substantially different initial situation regarding weight distribution of the examined small- to medium-sized dogs and large dogs, a unilateral hindlimb lameness leads to the same compensatory changes (cranial and lateral shift of the body mass centre).

Effects of forelimb instrumentation on lameness detection in horses using a portable inertial sensor-based system.

To investigate the effects of a small sensor attached to the pastern region of a forelimb on lameness detection and quantification with a portable inertial sensor-based system (PISBS) for lameness detection and quantification in horses. 20 adult horses (body weight, 410 to 650 kg) with no visible lameness at the walk. In a crossover study design, horses were evaluated at the trot twice using the PISBS with the gyroscope alternately attached to the right forelimb pastern region (as recommended by the manufacturer) or to the left forelimb pastern region (with the sensor flipped 180° on the frontal plane relative to the standard position). Agreement between the 2 instrumentation approaches was investigated graphically and by repeated-measures ANOVA, Pearson correlation analysis, and Bland-Altman analysis. No effects of instrumentation of a forelimb with the gyroscope were detected on the lame limb or limbs or on lameness severity. Attachment of the gyroscope to a forelimb had no effect on forelimb or hind limb lameness (ie, did not cause or mask lameness) as measured with the PISBS. Instrumentation of a forelimb with a lightweight gyroscope for lameness evaluations with a PISBS had no effects on lameness measurements in horses. Results suggested that, when indicated, the gyroscope can be attached (while flipped 180° on the frontal plane relative to the standard position) to the left forelimb (rather than the right forelimb).