bluuebunny/crossref_metadata_2025_split huggingface dataset:
Colic surgery in 206 juvenile Thoroughbreds: survival and racing results
Authors: SANTSCHI E. M. , SLONE D. E. , EMBERTSON R. M. , CLAYTON M. K. , MARKEL M. D. 
Published: June 2010

SummaryThe purpose of our study was to determine the types of lesions that cause colic in juvenile Thoroughbreds, factors associated with these lesions and the subsequent survival and athletic performance of the juveniles. The age of juvenile Thoroughbreds requiring surgical exploration for abdominal pain has an influence on the type of lesion causing colic. The short‐term survival rate (discharge from the hospital) after colic surgery for foals was 85% and was strongly influenced by the lesion causing colic. Thirteen percent of juveniles recovered from the first surgery experienced another severe colic episode requiring additional surgery or euthanasia. Eight percent of foals recovered from the first celiotomy developed adhesions. Adhesion formation was related to the initial lesion causing colic and the foals' age at the first surgery. Foals being suckled (15 days to 6 months) were at greatest risk for adhesions and more frequently required multiple surgeries. Juvenile Thoroughbreds that had a celiotomy were significantly less able to race (63%) than their unaffected siblings (82%), and age at the initial surgery was associated with the percentage of horses that raced. However, affected foals able to race won as much money, raced as often, and made as many starts as their siblings. Colic and surgical treatment have a negative impact on athletic performance, but the majority of foals discharged from the hospital after colic surgery will perform athletically as adults.
Effect of extensive ileal resection with a large resulting mesenteric defect and stapled ileal stump in horses with a jejunocaecostomy: a comparison with other anastomotic techniques
Authors: BLADON B. M. , HILLYER M. H. 
Published: June 2010

SummaryExtensive resection of the ileum of the horse, using automated stapling equipment followed by a stapled jejunocaecostomy, without closure of the mesenteric defect, was evaluated prospectively as a surgical treatment for lesions involving the distal small intestine. Of 153 horses treated surgically for colic, 10 horses with strangulating lesions involving the distal ileum were treated by extensive resection and jejunocaecal anastomosis leaving a residual mesenteric defect. These were compared with 12 horses with jejunoileal lesions treated by jejunocaecal anastomosis with closure of the mesentery, and 19 horses with distal jejunal lesions treated with an end‐to‐end jejunojejunal anastomosis and mesenteric closure. Long‐term (>7 months) and short‐term survival, duration of surgery, length of intestine resected, time from completion of surgery until the horse first defaecated and the highest recorded postoperative plasma fibrinogen level were assessed. There were no significant differences between the surgical techniques for any of the assessed parameters, but there was a trend to significance with a higher death rate following discharge from the hospital when cases of jejunocaecal anastomosis with a residual mesenteric defect were compared to cases of end‐to‐end jejunojejunal anastomosis with closure of the mesentery (P = 0.06). This study suggests that a stapled distal ileal resection and jejunocaecal anastomosis leaving a residual mesenteric defect is a satisfactory technique when pathological changes necessitate resection of the distal ileum. However, in this study, jejunocaecal anastomosis with or without mesenteric closure produced inferior results compared to jejunojejunal anastomosis.
Diagnosis and treatment of chronic recurrent caecal impaction
Authors: HUSKAMP B. , SCHEIDEMANN W. 
Published: June 2010

SummaryNinety‐six horses with chronic recurrent caecal impaction associated with hypertrophy of muscle layers in the caecal base or in the whole caecum were examined from 1990 to 1996. Enlargement of the caecocolic orifice was completed surgically in 58 horses. Of those horses having surgery, 50 were discharged from the hospital while 8 were subjected to euthanasia at the hospital due to complications. Twenty‐seven of the 50 horses discharged were normal at follow‐up while 23 died or were subjected to euthanasia due to acute or recurrent colic, recurrent impaction in the ascending or descending colon, complete caecal muscle layer hypertrophy, stomach rupture or lymphosarcoma. Approximately 50% of the cases were successfully treated by surgical enlargement of the caecocolic orifice. The results suggest, on the other hand, that enlargement of the caecocolic orifice was not successful in treating horses with hypertrophy of the caecal muscle layer in the whole caecum.
Evaluation of uniformity of morphological injury of the large colon following severe colonic torsion
Authors: van HOOGMOED L. , SNYDER J. R. , PASCOE J. R. , OLANDER H. J. 
Published: June 2010

SummaryThis report describes the evaluation of uniformity of morphological injury of the large colon following severe colonic torsion in 17 horses presented to the Veterinary Medical Teaching Hospital. In 16 horses, twist occurred at the colonic base and in 1 at the sternal and diaphragmatic flexure. Eleven of the 17 horses were subjected to euthanasia at surgery and 6 of 17 following surgical correction within 4 days postoperatively. The objective of this study was to determine if the degree of histological changes present at the pelvic flexure were uniformly distributed throughout the regions of the colon involved in cases of severe colonic torsion.
The medical management of eight horses with Grade 3 rectal tears
Authors: MAIR T. S. 
Published: June 2010

SummaryEight horses withGrade 3brectal tears of the peritoneal part of the rectum or small colon were treated by a combination of medical therapy and dietary manipulation. All of the horses developed septic peritonitis during the course of treatment. Medical therapy consisted of a combination of penicillin, gentamicin and flunixin meglumine administered parenterally, metronidazole administered orally and liquid paraffin administered by nasogastric tube. Some horses also received fluid and electrolyte therapy i.v., plasma and heparin i.v. All horses were maintained on a laxative diet. Six of the 8 horses recovered. Duration of therapy in the horses that survived was between 2 and 7 weeks. Three of the 6 horses that recovered developed a rectal diverticulum, which did not appear to cause any subsequent medical problems. In the 2 horses that died, theGrade 3rectal tear progressed to aGrade 4tear with subsequent faecal contamination of the abdomen. Manual evacuation of the cavity of the rectal tears during treatment and size of the tears were identified as possible causes for the progression of the disease in these 2 horses.
Forelimb tendon loading during jump landings and the influence of fence height
Authors: MEERSHOEK L. S. , SCHAMHARDT H. C. , ROEPSTORFF L. , JOHNSTON C. 
Published: June 2010

SummaryLameness in athletic horses is often caused by forelimb tendon injuries, especially in the interosseus tendon (TI) and superficial digital flexor tendon (SDF), but also in the accessory ligament (AL) of the deep digital flexor tendon (DDF). In an attempt to explain the aetiology of these injuries, the present study investigated the loading of the tendons during landing after a jump. In jumping horses, the highest forces can be expected in the trailing limb during landing. Therefore, landing kinematics and ground reaction forces of the trailing forelimb were measured from 6 horses jumping single fences with low to medium heights of 0.80, 1.00 and 1.20 m. The tendon forces were calculated using inverse dynamics and anin vitromodel of the lower forelimb. Calculated peak forces in the TI, SDF and DDF+AL during landing were 15.8, 13.9 and 11.7 kN respectively. The relative loading of the tendons (landing forces compared with failure forces determined in a separate study) increased from DDF to TI to SDF and was very high in SDF. This explains the low injury incidence of the DDF and the high injury incidence of the SDF. Fence height substantially influenced SDF forces, whereas it hardly influenced TI forces and did not influence AL strain. Reduction of fence height might therefore limit the risks for SDF injuries, but not for TI and AL injuries.
Effect of walking velocity on hindlimb kinetics during stance in normal horses
Authors: KHUMSAP S. , CLAYTON H. M. , LANOVAZ J. L. 
Published: June 2010

SummaryThe objectives of this study were to measure the effect of walking velocity on net joint moments and joint powers in the hindlimb during stance and to use the data to predict these variables at different walking velocities. Videographic and force data were collected synchronously from 5 sound horses walking over a force plate at a range of velocities. Force and kinematic data from 56 trials were combined using an inverse dynamic solution to determine net joint moments and joint powers. Analysis by simple regression and correlation (P<0.05, r2>0.30, r>0.50) showed that, in early stance, there were significant velocity‐dependent increases in the peak magnitudes of the following variables: extensor moment and positive power at the hip, flexor moment and positive power at the stifle, extensor moment, negative and positive power at the tarsus, and flexor moment and negative power at the fetlock. In late stance, there were significant velocity‐dependent increases in the peak magnitudes of the following variables: flexor moment at the hip, negative power at the stifle and flexor moment and positive power at the tarsus. As velocity increased, the hip showed an increase in energy generation, whereas the tarsus showed increases in both energy generation and absorption. It is concluded that an increase in walking velocity is associated with increases in peak magnitudes of the net joint moments and joint powers in the hindlimb; and that energy generation at the hip makes the largest contribution to the increase in velocity.
In vitro comparison between a DCP and external fixator for pancarpal arthrodesis in the dog
Authors: VIGUIER E. , ZNATY D. , MEDELCI M. , DEGUEURCE C. 
Published: June 2010

SummaryMany clinical reports have previously documented the advantages of plates or external fixations but surgeons prefer to use plate for better acceptance by the owner, less dressing and a decreased rate of infection. In order to address complications of carpal surgery, infections, arthritis and osteomyelitis, external fixation is warranted. Twelve canine forelimbs, free of abnormality, were tested under compression to evaluate thein vitrobiomechanical behaviour of the normal carpus. This behaviour was compared with that of a stabilized carpus stabilised by panarthrodesis with either plates (8 hole 3.5 mm dynamic compression plate (DCP), or atype IIexternal fixator.Deformation vs. load was recorded after compression with a testing machine in conjunction with a digital data acquisition system. Yield load, maximal load to failure and stiffness were then calculated. Variables were significantly greater for arthrodesis with external fixation and plates than for intact forelimbs. The stiffness and the MLF after stabilisation with plates or external fixators did not differ significantly. At MLF, fracture of the third metacarpus appeared with plates, whereas deformations of the pins and bars of the external fixators increased with load. Stabilisation with plate or external fixation allowed more load to failure than the intact carpus. The biomechanical behaviour of both methods of arthrodesis was identical during loading. However, after rupture, external fixation was more plastic. External fixation, which is less often used than plates for pancarpal arthrodesis, mainly due to the occurrence of sepsis, may be useful for arthrodesis of the carpus in big or active dogs.
Sciatic nerve transection in adult and young rats: abnormal EMG patterns during locomotion
Authors: GRAMSBERGEN A. , van EYKERN L. A. , MEEK M. F. 
Published: June 2010

SummaryTransections of peripheral nerves usually lead to serious handicaps. In order to enhance insights into the poor functional recovery, we studied the effects of a unilateral sciatic nerve lesion in adult and young rats. Electromyographic (EMG) patterns of the tibialis anterior (a hindlimb flexor) and the gastrocnemius muscle (a hindlimb extensor) during walking were recorded after transecting the sciatic nerve at adult age and at the 10th postnatal day.After recovery periods lasting up to 21 weeks, EMG patterns in the hindleg muscles during locomotion were highly abnormal, irrespective of the age at lesioning. Electromyographic bursts were markedly irregular and, generally, coactivation of these antagonists was observed during walking. Other evidence has shown that after peripheral nerve transection, nerves randomly reinnervate their target muscles and we conclude that the patterns of muscle activity may be associated with the properties of foreign, as well as genuine, motor nerves.Behaviourally, walking patterns after a transection at adult age are markedly abnormal but, after transection at the 10th day, locomotion is much less disturbed. The finding of a discrepancy between a near normal walking pattern in rats operated on at a young age and severely disturbed EMG activity may be due to subtle readjustments in the force recruitment in the respective muscles, despite a random reinnervation by the sciatic nerve branches. These compensatory readjustments are particularly prominent after transection at an early age.
Determination of hoof mass and centre of mass from morphological measurements
Authors: ARABIAN A. K. , LANOVAZ J. L. , CLAYTON H. M. 
Published: June 2010

SummaryDetermination of net joint moments and powers requires accurate measurements of mass and centre of mass (COM) for the limb segments. The objective of this research was to develop regression equations for calculating mass and COM of the hoof segment that are applicable over a wide range of hoof morphologies. Ninety‐one hooves (mean ± s.d. 0.99 ± 0.50 kg) were weighed and the 3‐dimensional COM determined using a mass balance technique. Ten morphological variables were measured and used as independent variables in linear regressions with dependent variables of mass and centre of mass. The regression equation for mass was dependent upon coronet circumference, lateral height, solar length, solar width, heel height, toe height and base circumference (r2 = 0.978). Mediolateral COM was dependent only on solar length (r2 = 0.874). Dorsopalmar COM depended only upon solar length (r2 = 0.792) and vertical COM was defined only by lateral height (r2 = 0.377). Midlateral COM, measured at the midhoof wall along the tubules, was found to depend on coronet circumference, lateral height, toe length and toe height (r2 = 0.414). The large sample size and the inclusion of a variety of hoof masses and morphologies allow these results to be generalised to a wide range of the equine population. It was concluded that the mass and COM of the hoof segment can be estimated to a high degree of accuracy based on easily obtained morphological measurements.
Quantification of hoof deformation using optical motion capture
Authors: BURN J. F. , BROCKINGTON C. 
Published: June 2010

SummaryDeformation of the hoof capsule occurs during stance phase as a result of loading by the distal phalanx. The objective of this study was to evaluate optical motion capture as a technique for measuring hoof deformation during locomotion, and to quantify the deformation of the dorsal wall during stance phase. The front left feet of 3 clinically sound horses were used for this study. The hoof wall was cleaned and 9 retroreflective markers were glued to the lateral and dorsal hoof wall, and shoe. Each horse was trotted in a straight line at constant speed while marker positions during stance phase were recorded at 240 frames/s using a 3‐dimensional (3‐D) motion capture system.Similar patterns of hoof deformation were seen in all horses; the dorsal wall moved inwards towards the axis of the limb with displacement increasing proximally. Mean peak deformation varied between 0.17 and 0.92 mm in the dorsal hoof wall, and 0.18 and 0.76 mm in the lateral hoof wall. In all horses, movement of the shoe relative to the ground was <0.7 mm throughout stance phase and movement of the hoof relative to the shoe was <0.3 mm. Calibration using a micrometer indicated the motion capture system was accurate to <0.1 mm in the configuration used for the study.This study showed that optical motion capture can be used to measure hoof deformation and successfully addresses some of the limitations of existing methods.
A method to determine mechanical energy conservation and efficiency in equine gait: a preliminary study
Authors: PREEDY D. F. , COLBORNE G. R. 
Published: June 2010

SummaryMetabolic and mechanical energy costs of locomotion can be combined to calculate locomotor efficiency, which is the quotient of the mechanical energy and metabolic costs. The purpose of this pilot study was to evaluate the mechanical and metabolic energy costs of locomotion at a range of 7 trotting speeds (2.5 to 6.2 m/s) on a level treadmill. A single, sound Thoroughbred horse was modelled as a system of 15 linked segments incorporating all 4 limbs, head, neck and trunk. The horse performed a continuous incremental exercise test at increasing trotting speeds while VO2 was recorded using a breath‐by‐breath gas analysis system. Positional data were recorded concurrently at 100 Hz using a 2‐camera infrared kinematic system. Mechanical energy cost was calculated for 3‐6 strides per speed increment, and metabolic data were obtained during the last 15 s of each speed step. Mechanical energy cost increased linearly from 3.3 J/kg/m at 2.5 m/s to a value of 5.31 J/kg/m at 6.2 m/s, and the within‐subject variability was low at each of the speed steps. This analysis accounted for the important energy‐conserving mechanisms of energy exchange within and between segments of the link segment model. Within‐segment energy conservation remained approximately constant as speed increased, whereas between‐segment conservation increased from 1040 to 4502 J/stride. The combination of both metabolic and mechanical costs of locomotion yielded an inverted bell‐shaped curve of ‘apparent’ efficiency across the speed increments, with the maximum value occurring when metabolic cost was lowest at 3.8 m/s.
Gait transitions during unrestrained locomotion in dogs
Authors: BLASZCZYK J. W. 
Published: June 2010

SummaryGait transitions during long distance, unrestrained locomotion were studied in 22 mongrel dogs. Spatial and temporal limb movement parameters were collected and the phase relationships between limb movements based upon a 2‐dimensional (2‐D) gait diagram were computed. During most of the trials, the dogs trotted within a relatively narrow velocity range. Gait transitions were observed during radical changes of the movement velocity. In most cases the gait switches were abrupt and completed within 2 strides of the gait cycle. The dogs walked, depending on the animal size, within the upper velocity range of 0.93‐1.21 m/s. Most of the walk‐trot transitions were observed within this range. All of them had a typical pattern that involved changes of the phase shift between diagonal limb movements from 0.31 ± 0.02 (a typical value for a walking dog) down to 0.02 ± 0.03. These changes appeared abruptly within one stride cycle for each diagonal pair of limbs; therefore, the transition was completed in 2 strides of the gait cycle. The switch involved momentary shortening of the hindlimb amplitudes. During the next gait cycle, all limb movement amplitudes were reduced with a concomitant increase in limb movement frequencies.In contrast to the clear border between the symmetrical gaits, the dogs switched to gallop at any speed within the trot range (most frequently between 1.5‐2.6 m/s). The transitions were usually completed within one stride of the diagonal limbs. In most cases, the switch from trot to gallop had a similar pattern; while maintaining synchronous movement of one diagonal pair of limbs, the other pair movement control was modified accordingly. The typical transition pattern involved the shortening of the swing phase in the front limb with simultaneous lengthening of the swing phase in the diagonal hindlimb. These transient modifications had their equivalent in the analogous limb movement amplitude changes. A mirror‐image pattern of phase changes was observed in the majority (82%) of the gallop‐trot transitions. Three of the dogs, however, besides the typical gallop‐trot switch, occasionally employed a second pattern of transition.
Kinematic analysis of the symmetry of limb movements in lame trotting horses
Authors: AUDIGIÉ F. , POURCELOT P. , DEGUEURCE C. , GEIGERT D. , DENOIX J. ‐M. 
Published: June 2010

SummaryThis study was undertaken to describe the symmetry of movements of fore‐ and hindlimbs in horses suffering from various spontaneous lamenesses. Two groups of horses were studied: 13 clinically sound horses and 24 lame horses. Using a 3‐dimensional (3‐D) kinematic analysis system, movements of both sides of each horse were recorded simultaneously while trotting on a track. The differences in motion between left and right homologous joints of each horse were quantified using symmetry indices based on an intercorrelation method. Symmetry indices obtained for each lame horse were then compared with those of sound horses. This comparison showed that the most sensitive lameness indicators were the symmetry indices of the vertical displacement of the proximal markers of the limbs. Symmetry indices of each lame horse were also compared with those of the other lame horses, using correlation coefficients to determine whether or not various lamenesses generate similar alterations of the locomotion symmetry. Values of these coefficients allowed 2 types of lameness to be distinguished. In 21 lame horses, the largest alterations in the symmetry of vertical movements were observed for the proximal markers of the limbs, which may reflect the supporting component of these lamenesses. In contrast, the asymmetries in vertical movements were more pronounced for the distal markers in 3 horses (one stringhalt and 2 carpal injuries), which may reflect the swinging component of these lamenesses. This cross‐correlation method can be implemented easily in a computer programme and may represent a first step in the development of an expert system.