bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conservative management of 17 horses with nonarticular fractures of the tibial tuberosity
Authors: ARNOLD C. E. , SCHAER T. P. , BAIRD D. L. , MARTIN B. B. 
Published: April 2007

Summary Reasons for performing study: Fractures of the tibial tuberosity (FTT) are caused by direct trauma, and are the second most commonly reported injury in event horses with stifle trauma. Conservative management of horses with FTT has been advocated, but results and prognosis for this method of therapy are unknown. Objectives: To report and review the findings of a retrospective study of 17 horses admitted to a veterinary teaching hospital from 1986–2001 with nonarticular FTT that received conservative management. Methods: Subject details, aetiology of the accident, limb affected, degree of lameness at time of admission, size and degree of displacement of the fracture fragment, complications such as comminution of the fracture fragment or damage to soft tissue structures within the affected stifle, and treatment recommendations were obtained from medical records. Owners and trainers were contacted regarding the horse's return to athletic use. The follow‐up period consisted of 11–154 months. Results: Two horses were reportedly sound, but unable to return to competition for unrelated reasons. Of the horses that completed the rehabilitation period, 12/15 (80%) returned to athletic use at the same level as before the injury. Three horses were diagnosed with damage to soft tissue supporting structures of the affected stifle and could not return to their former level of competition. Conclusions: Concurrent soft tissue damage, diagnosed at the time of the initial injury, was statistically significant in precluding horses from returning to athletic careers. All other variables were found to have no effect upon outcome. Potential clinical relevance: This retrospective study suggests that the conservative management of nonarticular FTT is a viable treatment modality in managing athletic equine patients presenting with these fractures.
Recombinant equine growth hormone administration: effects on synovial fluid biomarkers and cartilage metabolism in horses
Authors: DART A. J. , LITTLE C. B. , HUGHES C. E. , CHU Q. , DOWLING B. A. , HODGSON D. R. , ROSE R. J. , JOHNSON K. A. 
Published: April 2007

SummaryReasons for performing study: Recombinant equine growth hormone (reGH) has recently been evaluated for effects on body condition and wound healing. It has the potential to influence articular cartilage via stimulation of IGF‐1.Objectives: To investigate effects of administration on synovial joint metabolism.Methods: Six mature horses were given 20 μg/kg bwt reGH daily for 8 weeks by i.m. injection. Three control horses were injected with sterile water. Serum and synovial fluid samples were collected at 6, 8, 11 and 16 weeks for GH and IGF‐1 assays. Articular cartilage harvested at week 16 was evaluated by Western analysis using monoclonal antibodies BC‐13, BC‐4, 8‐A‐4 and CH‐3.Results: Concentrations of IGF‐1 in serum and synovial fluid were significantly elevated (P < 0.05) at 6 and 8 weeks in the reGH group. Glycosaminoglycan concentrations in synovial fluid were significantly less than controls at these time points, suggesting that reGH may modulate proteoglycan metabolism in articular cartilage. In the reGH group, there were not any alterations in synovial fluid content of 3B3(‐) epitope or aggrecan metabolite, or in aggrecan or link protein catabolites retained within cartilage, that might be expected with development of osteoarthritis.Conclusions: Intramuscular administration of reGH may be a more efficient means of delivery of IGF‐1 to joints for cartilage resurfacing initiatives.Potential relevance: We found no alterations in cartilage metabolism indicative of development of osteoarthritis.
Effects of propylthiouracil and bromocryptine on serum concentrations of thyrotrophin and thyroid hormones in normal female horses
Authors: JOHNSON P. J. , IV N. T. MESSER , GANJAM V. K. , THOMPSON D. L. , REFSAL K. R. , LOCH W. E. , ELLERSIECK M. R. 
Published: April 2007

SummaryReasons for performing study: There exists a need for better diagnostic tests to characterise thyroid disease in horses. Currently available diagnostic tests fail to diff erentiate between thyroid gland disorders and thyroid abnormalities resulting from pituitary or hypothalamic problems.Objectives: To evaluate the effects of treatment with propylthiouracil (PTU) and bromocryp tine (BROM) on serum concentrations of triiodothyronine (T3), thyroxine (T4), reverse T3 (rT3) and equine thyroid‐stimulating hormone (e‐TSH, thyrotrophin) in mature horses.Methods: Healthy mature horses were treated using either PTU or BROM for 28 days. The effect of treatment on the thyroid axis was assessed by measuring T3, T4, rT3 and e‐TSH before and at +14 and +28 days. The effect of PTU and BROM on the response of T3, T4, rT3 and e‐TSH to thyrotrophin‐release hormone (TRH) administration was also assessed before and at +14 and +28 days of treatment.Results: Treatment with PTU led to a significant reduction in serum concentrations of T3, T4 and rT3 on Day 28 and increase of e‐TSH on Day 28 (P < 0.05). Treatment with BROM did not cause any measurable effect on serum concentrations of T3, T4, rT3 or e‐TSH. The percentage increment by which serum concentration of T4, T3 and e‐TSH increased following stimulation with TRH was decreased by treatment with PTU for 28 days (P < 0.05) but were not affected by treatment with BROM for 28 days.Conclusions: These results suggest that 1) treatment with PTU may be used in horses as a model of primary hypothyroidism; 2) the use of BROM as a model of secondary hypothyroidism in horses is not supported; and 3) e‐TSH assay deserves further investigation for the clinical diagnosis of thyroid axis dysfunction in horses.Potential relevance: Propylthiouracil effectively causes primary hypothyroidism. There is substantial variability between horses with respect to their sensitivity to this substance when administered orally. Further studies pertaining to the characterisation of equine thyroid disorders are warranted and the use of both PTU for the experimental induction of primary hypothyroidism and e‐TSH for the diagnostic characterisation of thyroid disorders in horses should be considered.
Energetic and kinematic consequences of weighting the distal limb
Authors: WICKLER S. J. , HOYT D. F. , CLAYTON H. M. , MULLINEAUX D. R. , COGGER E. A. , SANDOVAL E. , MCGUIRE R. , LOPEZ C. 
Published: April 2007

SummaryReason for performing study: It is well known that adding a load to a horse's back increases its energetic costs of locomotion, but the magnitude of increase obtained by loading the most distal portion of limb has not been measured.Objectives: To measure oxygen consumption in horses with mass added to the back and hooves. Because such mass distribution alters inertial parameters of the limbs, kinematic measurements were made to quantify the magnitude of change in limb movement.Methods: Steady‐state oxygen consumption was measured in 6 horses with a load of 2.4 kg. The load was either carried on the back or distributed equally between the 4 limbs. Modified bell boots kept the mass at the level of P3. Horses trotted on a treadmill at speeds ranging from 2 to 5 m/sec (in 0.5 m/sec increments). High‐speed (250 Hz) digital images were recorded in a sagittal plane and the positions of retroreflective markers located on standard positions on the limbs were digitised for kinematic analysis.Results: Loading of the distal limbs produced a 6.7% increase in metabolic rate, an order of magnitude higher than when the mass was added over the back. Although the stride period was 2% longer in horses with loads on the distal limbs, time of contact and duty factor were not different. Distal limb loading increased the range of motion in hind‐but not forelimbs.Conclusions: The costs of swinging the limbs in the horse are considerable and the addition of weights to the distal limb can have a profound effect on not only the energetics of locomotion but also the kinematics, at least in the hindlimb.Potential relevance: The use of weighted shoes, intended to increase animation of the gait, increases the metabolic effort of performance horses a disproportionate amount. The additional mass also increases the joint range of motion and, potentially, the likelihood of injury.
Determination of the stiffness of the equine spine
Authors: SCHLACHER C. , PEHAM C. , LICKA T. , SCHOBESBERGER H. 
Published: April 2007

Summary Reasons for performing study: Mechanical properties of the equine back are the bases for realistic modelling of the back, which is recognised as an important step towards improved understanding of the pathogenesis of equine back conditions. Hypothesis: The stiffness of the equine back depends on the direction of the applied force and on the position of the spine. Methods: Fourteen dissected spines were tested in a tensile testing machine. In 3 different positions, simulating dorsoventral, laterolateral and dorsoventral‐30° rotated movement, force was applied on the dorsal spinous process of T12 to reach an excursion of 4 cm in each direction. The normal distribution of the stiffness coefficients was tested with a Kolmogorov‐Smirnov test and the stiffness coefficients were compared with paired t tests. Results: Mean ± s.d. dorsoventral stiffness was 2093 ± 611 N/m for the nonrotated spine and 2182 ± 459 N/m for the 30° rotated spine. Mean laterolateral stiffness was significantly lower than dorsoventral stiffness at 1454 ± 156 N/m. Conclusions: The stiffness of the spine depends on the direction of loading. Potential relevance: The stiffness of the spine under loading may be a relevant factor in the development of back disorders.
Development of a 3D model of the equine distal forelimb and of a GRF shoe for noninvasive determination of in vivo tendon and ligament loads and strains
Authors: ROLLOT Y. , LECUYER E. , CHATEAU H. , CREVIER‐DENOIX N. 
Published: April 2007

Summary Reasons for performing study: As critical locomotion events (e.g. high‐speed and impacts during racing, jump landing) may contribute to tendinopathies, in vivo recording of gaits kinematic and dynamic parameters is essential for 3D reconstruction and analysis. Objective: To propose a 3D model of the forelimb and a ground reaction force recording shoe (GRF‐S) for noninvasively quantifying tendon and ligament loads and strains. Methods: Bony segments trajectories of forelimbs placed under a power press were recorded using triads of ultrasonic kinematic markers linked to the bones. Compression cycles (from 500–6000 N) were applied for different hoof orientations. Locations of tendon and ligament insertions were recorded with regard to the triads. The GRF‐S recorded GRF over the hoof wall and used four 3‐axis force sensors sandwiched between a support shoe and the shoe to be tested. Results: Validation of the model by comparing calculated and measured superficial digital flexor tendon strains, and evaluation of the role of proximal interphalangeal joint in straight sesamoidean ligament and oblique sesamoidean ligament strains, were successfully achieved. Objective comparisons of the 3 components of GRF over the hoof for soft and hard grounds could be recorded, where the s.d. of GRF norm was more important on hard ground at walk and trot. Conclusions: Soft grounds (sand and rubber) dissipate energy by lowering GRF amplitude and diminish bounces and vibrations at impact. At comparable speed, stance phase was longer on soft sand ground. Potential relevance: The conjugate use of the GRF‐S and the numerical model would help to quantify and analyse ground/shoe combination on comfort, propulsion efficiency or lameness recovery.
Effects of 6° elevation of the heels on 3D kinematics of the distal portion of the forelimb in the walking horse
Authors: CHATEAU H. , DEGUEURCE C. , DENOIX J.‐M. 
Published: April 2007

SummaryReasons for performing study: Understanding of the biomechanical effects of heel elevation remains incomplete becausein vivostudies performed with skin markers do not measure the actual movements of the 3 digital joints.Objective: To quantify the effects of 6° heel wedge on the 3‐dimensional movements of the 4 distal segments of the forelimb in the walking horse.Methods: Four healthy horses were used. Kinematics of the distal segments was measured invasively with a system based on ultrasonic triangulation. Three‐dimensional rotations of the digital joints were calculated by use of a ‘joint coordinate system’ (JCS). Data obtained with heel wedges were compared to those obtained with standard shoes during the stance phase of the stride.Results: Heel wedges significantly increased maximal flexion of the proximal (PIPJ) and distal (DIPJ) interphalangeal joints and maximal extension (mean ± s.d. +0.8 ± 0.3°) of the metacarpophalangeal joint (MPJ). Extension of the PIPJ and DIPJ was decreased at heel‐off. Few effects were observed in extrasagittal planes of movement.Conclusions: Heel wedges affect the sagittal plane kinematics of the 3 digital joints.Potential relevance: Controversial effects previously observed on the MPJ may be explained by the substantial involvement of the PIPJ, which was wrongly neglected in previous studies performed on the moving horse.
Evaluation of pressure distribution under an English saddle at walk, trot and canter
Authors: FRUEHWIRTH B. , PEHAM C. , SCHEIDL M. , SCHOBESBERGER H. 
Published: April 2007

Summary Reasons for performing study: Basic information about the influence of a rider on the equine back is currently lacking. Hypothesis: That pressure distribution under a saddle is different between the walk, trot and canter. Methods: Twelve horses without clinical signs of back pain were ridden. At least 6 motion cycles at walk, trot and canter were measured kinematically. Using a saddle pad, the pressure distribution was recorded. The maximum overall force (MOF) and centre of pressure (COP) were calculated. The range of back movement was determined from a marker placed on the withers. Results: MOF and COP showed a consistent time pattern in each gait. MOF was 12.1 ± 1.2 and 24.3 ± 4.6 N/kg at walk and trot, respectively, in the ridden horse. In the unridden horse MOF was 172.7 ± 11.8 N (walk) and 302.4 ± 33.9 N (trot). At ridden canter, MOF was 27.2 ± 4.4 N/kg. The range of motion of the back of the ridden horse was significantly lower compared to the unridden, saddled horse. Conclusions and potential relevance: Analyses may help quantitative and objective evaluation of the interaction between rider and horse as mediated through the saddle. The information presented is therefore of importance to riders, saddlers and equine clinicians. With the technique used in this study, style, skill and training level of different riders can be quantified, which would give the opportunity to detect potentially harmful influences and create opportunities for improvement.
Endoscopic scoring of mucus quantity and quality: observer and horse variance and relationship to inflammation, mucus viscoelasticity and volume
Authors: GERBER V. , STRAUB R. , MARTI E. , HAUPTMAN J. , HERHOLZ C. , KING M. , IMHOF A. , TAHON L. , ROBINSON N. E. 
Published: April 2007

SummaryReasons for performing study: Endoscopic scoring of airway mucus quantity and quality has not been critically assessed.Objectives: To evaluate mucus scores for 1) observer‐ and horse‐related variance and 2) association with inflammation, mucus viscoelasticity and measured volume.Methods: Variance of scoring within and between observers and over time within horses were determined for airway mucus accumulation, apparent viscosity, localisation and colour, and correlations of mucus accumulation scores with neutrophil ratios in secretions. The relationship of accumulation score to measured volumes of ‘artificial mucus’ was investigated. Correlations of mucus accumulation, apparent viscosity and colour scores with measured viscoelasticity were tested. Viscoelasticity was compared between tracheal secretion samples collected ventrally and dorsally.Results: Mucus accumulation scoring showed excellent interobserver agreement and moderate horse‐related variance, was related to measured volumes of ‘artificial mucus’, and correlated well with neutrophilic airway inflammation. Scores of mucus viscosity, colour and localisation showed high observer‐related variance. Mucus accumulation, apparent viscosity and colour scores did not correlate with measured tracheal mucus viscoelasticity, but dorsally‐localised mucus showed 2‐fold higher measured viscoelasticity than ventrally‐localised samples.Conclusions: Mucus accumulation scores are a reproducible measure of mucus volumes in the trachea.Potential relevance: Endoscopic scoring of mucus accumulation is a reliable clinical and research tool. In contrast, apparent viscosity, localisation and colour scores should be interpreted with caution.
A dose titration of triamcinolone acetonide on insulin‐like growth factor‐1 and interleukin‐1‐conditioned equine cartilage explants
Authors: Sandler E. A. , Frisbie D. D. , MCIlwraith C. W. 
Published: April 2007

SummaryReasons for performing study: Previousin vitropilot studies have defined a potentially beneficial effect of insulin‐like growth factor‐1 (IGF‐1) and triamcinolone acetonide (TA) on interleukin‐1 (IL‐1)‐conditioned equine cartilage. Furthermore, an optimal dose for IGF‐1 treatment alone has been documented previously using the same test system as in the current project.Objectives: To perform a dose titration of TA on IL‐1‐conditioned equine articular cartilage explants in the presence of an optimised IGF‐1 dose, in order to optimise a triamcinolone concentration for use in combination with IGF‐1 for future investigations.Methods: Cartilage explants were harvested from the distal femur of a normal horse. The effect of a clinically relevant TA dose range was evaluated in the presence of IL‐1 and IGF‐1 through measurement of proteoglycan (PG) matrix metabolism (synthesis and degradation).Results: TA and IGF‐1 in combination inhibited the IL‐1‐induced release of PG matrix components (glycosaminoglycan or GAG) from the articular cartilage, as well as producing a significant increase in GAG synthesis.Conclusions: This experiment provided proof of principle that a combination treatment appears to be able to combat the IL‐1‐induced matrix depletion, while enhancing anabolic metabolism within the articular cartilage.Potential relevance: The use of IGF‐1 in conjunction with TAin vivohas the potential to provide beneficial anabolic effects not seen with TA alone.
High detail radiography and histology of the centrodistal tarsal joint of Icelandic horses age 6 months to 6 years
Authors: Björnsdóttir S. , Ekman S. , Eksell P. , Lord P. 
Published: April 2007

SummaryReasons for performing study: Osteoarthrosis (OA) in the distal tarsal joints, bone spavin, is a well known condition which is common in Icelandic horses age 6–12 years.Objectives: To determine the nature, location and age of appearance of early radiographic and histological changes in the centrodistal tarsal joint (CD) of young Icelandic horses.Methods: Slab sections from the CD of young Icelandic horses were examined by high detail radiography (age 6 months to 6 years, n = 111) and histology (age 6 months to 4 years, n = 82) to detect and describe the early changes indicative of OA. Horses younger than 5 years were unridden.Results: Chondronecrotic lesions histologically similar to those described in the early pathogenesis of OA were seen in 33% of the joints, located both medially and laterally. Radiographic sclerosis of the subchondral bone was recorded in 60% of the specimens, most often medially. Medial location was not associated with chondronecrosis, but was strongly related to age. Sclerosis was an infrequent finding on the lateral side, and was probably secondary to chondronecrosis in the corresponding part of the joint. Small defects in the subchondral bone were considered to be the most specific radiographic sign of OA as they were strongly associated with chondronecrosis.Conclusions: The high prevalence of chondronecrosis in the young horses indicates an early onset and slow progression of the disease. The early appearance also shows that the initiation of the disease is unrelated to the use of horses for riding. As clinical manifestation of OA in the distal tarsal joints is most often described in mature or old horses, the first stages of the disease are not likely to result in clinical signs. Subchondral bone sclerosis did not appear to be a primary factor in the development of OA in the CD but was considered to reflect an uneven distribution of biomechanical forces within the joint.Potential relevance: The development of OA in the CD of young Icelandic horses seems to be due to poor conformation or joint architecture rather than trauma or overloading. These aetiological factors are likely to be of importance for OA in the distal tarsal joints in other breeds as well. The influence of hindlimb conformation and the architecture of the distal tarsal joints on the biomechanics of joints need to be investigated, preferably by locomotion analysis in young horses.
Collagenase‐1 (MMP‐1) activity in equine synovial fluid: influence of age, joint pathology, exercise and repeated arthrocentesis
Authors: Brama P. A. J. , Van Den Boom R. , DEGroot J. , Kiers G. H. , Van Weeren P. R. 
Published: April 2007

Reasons for performing study: Matrix metalloproteinases (MMPs) are considered candidate biomarkers for both physiological and pathological tissue remodelling because of their key role in articular cartilage homeostasis. As disruption of the collagenous architecture is thought to be pivotal in chronic degenerative diseases such as osteoarthritis (OA), the collagenases form an interesting subset of the MMPs. The significance of any biomarker in synovial fluid (SF) can be assessed properly only when fluctuations in patterns induced by physiological processes such as development and growth, and by external influences and interventions such as exercise and repeated arthrocentesis, are known and taken into account.Objectives: To investigate the activity of MMP‐1 in equine SF at different stages of development and in joints affected by OA, and the influence of exercise and repeated arthrocentesis thereon.Methods: MMP‐1 activity was determined in SF of normal joints of fetal, juvenile and mature horses, and in SF of horses suffering from OA, using an internally quenched fluorogenic peptide substrate. MMP‐1 activity was also measured in SF from horses subjected to an exercise regimen and those subjected to repeated arthrocentesis.Results: An age‐related decline in the SF levels of active MMP‐1 was observed. MMP‐1 activity was 15‐fold higher in fetal than in juvenile animals, which showed significantly higher MMP‐1 activity levels than mature horses. In SF of OA joints, MMP‐1 activity was increased. Exercise did not affect MMP‐1 activity in SF, but repeated arthrocentesis (within 60 h) increased MMP‐1 activity significantly.Conclusions: The high MMP‐1 activity in SF of young individuals parallels the high metabolic activity occurring during rapid growth and differentiation at early age. The elevated MMP‐1 activity in SF of OA joints probably reflects pathological matrix degradation, confirming the potential of MMP‐1 to serve as a biochemical marker for early joint disease. Moderate exercise is not likely to influence the outcome of MMP‐1 activity measurements in equine SF, but arthrocentesis should be taken into account as a possible confounding factor.Potential relevance: Given the crucial role of the collagen matrix for tissue integrity, MMP‐1 activity may be a useful tool in diagnostic, therapeutic or prognostic studies in horses suspected of OA. However, care should be taken to exclude fluctuations in MMP‐1 activity induced by physiological processes such as development and growth, and by interventions such as repeated arthrocentesis.