bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of conformational aspects on the movement of the equine back
Authors: JOHNSTON C. , HOLM K. , FABER M. , ERICHSEN C. , EKSELL P. , DREVEMO S. 
Published: June 2010

SummaryThe relationship between structure and function is important in the judgement of the horse. Twenty sound riding horses walked and trotted on a treadmill. The movement of the backs of each of the horses was measured using a commercially available movement analysis system. Morphometric, spatiotemporal and kinematic information were correlated to investigate the effect of conformation on movement. Taller and heavier horses seem to have longer thoracic and lumbar backs, and are wider at the pelvis. Horses with longer strides extended and flexed their backs in the caudal saddle region to a greater extent at the walk, but not the trot. Horses with greater angle of L5 tend to extend and flex this region of the back more. At the walk and trot, a long thoracic back results in greater lumbar lateral bending. A negative relationship was found between the curvature of mid‐thoracic back and the amount of lateral bending of L1 and L3 and axial rotation of the pelvis at the trot. There are clear relationships between back conformation and movement that may be important to the orthopaedic health of the horse. Further understanding of the relationships between conformation, movement and injury may provide an objective basis for the evaluation of future performance and soundness.
Relationship between velocity and temporal variables of the flat shod running walk
Authors: NICODEMUS M. C. , HOLT K. M. , SWARTZ K. 
Published: June 2010

SummaryThe running walk of the Tennessee Walking Horse is often described as a faster variation of the walk, indicating the importance of velocity on the mechanics of the gait. Variations in gait variables create difficulties in clearly identifying the normal and abnormal running walk in a clinical evaluation. The objectives of this study were, therefore, to describe the flat shod running walk and to determine the relationship between velocity and the running walk. From frame‐by‐frame analysis of 60 Hz film, temporal variables were averaged for 6 strides from 6 horses performing an ‘easy’ (slow) and ‘strong’ (fast) running walk during a flat shod, easy‐rider Tennessee Walking Horse show class. The running walk at both velocities was a 4‐beat, symmetrical stepping gait with a lateral footfall sequence and lateral couplets. The velocity ranged from mean ± s.d. 2.66 ± 0.34 to 3.80 ± 0.18 m/s. For both velocities (slow, fast), hind stance as a percentage of stride duration (58 ± 3%, 56 ± 2%) was significantly longer than fore (51 ± 5%, 48 ± 1%); diagonal advanced placement (29 ± 2%, 37 ± 4%) and lift‐off (35 ± 5%, 39 ± 2%) were significantly longer than lateral (advanced placement: 22 ± 2%, 12 ± 3%; lift‐off: 18 ± 4%, 10 ± 2); and lateral bipedal support (50 ± 9%, 67 ± 7%) was significantly longer than diagonal (27 ± 6%, 16 ± 4%). Strong correlations were found between velocity and diagonal advanced placement (0.640), lateral lift‐off (‐0.924) and diagonal (‐0.648) and lateral (0.904) bipedal support. Understanding the running walk and the gait variations due to velocity may be important to both the performance and soundness of the Tennessee Walking Horse.
The effect of reins on kinetic variables of locomotion
Authors: BIAU S. , COUVE O. , LEMAIRE S. , BARREY E. 
Published: June 2010

SummaryThe equestrian literature and reports of experienced riders indicated that attitude of a horse's head and neck is related to the equine locomotion characteristics. The purpose of this study was to quantify the effects of 3 types of reins on locomotion at walk and trot. Eight saddle horses were tested in an automatic walker without reins, with rubber bands, Chambons and Back lift1, using the same procedure. The rubber bands closed the head‐neck angle, whereas the Chambons and the Back lift opened it. The gait characteristics were measured with the Equimetrix2 gait analysis system. Two accelerometric devices were fixed on the sternum and sacrum to measure the kinetic characteristics of the fore‐ and hindlimbs at walk and trot. Analysis of variance was used to test the effects of reins on the fore‐ and hindlimbs. All 3 types of reins significantly (P<0.05) modified walk and trot, with increased forelimb propulsion at the trot (P<0.05). Chambons increased the dorsoventral activity of the hindlimbs at the trot and hindlimb propulsion at the walk (P<0.05). Back lift increased forelimb dorsoventral activity both at the trot and walk (P<0.05). It was concluded that the Chambons increased the activity of the hindlimbs while Back lift increased that of the forelimbs.The use of reins modified the head placement and the fore‐and hindlimbs activity. The specific effect of each type of rein can be used for training, rehabilitation or management of locomotor's injury.
A radiographic technique to assess the longitudinal balance in front hooves
Authors: TACCHIO G. , DAVIES H. M. S. , MORGANTE M. , BERNARDINI D. 
Published: June 2010

SummaryThe aim of this study was to validate a radiographic technique to measure objectively the longitudinal hoof balance in the horse. Ten left third phalanges (P3) obtained from front hooves and 19 left front hooves were used in order to assess the reliability of the radiographic technique and to identify any effect of rotation or alignment of specimens or distance between the X‐ray machine and the radiographic cassette, in measuring P3s structures and balance related parameters. A rotational support was made to hold specimens in order to standardise some of the conditions of X‐raying. The main axis of the frog was used as a marker for the sagittal plane of P3. Results showed that single radiographic measurements could have wide limits of agreement with actual measurements of the hoof (gold standard values). In order to limit errors we suggest the use of a combination instead of single parameters to assess balance. Rotation of the hoof is also to be controlled when a measurement of angles is needed. The radiographic technique used in this study can be used to objecticely measure balance parameters considered important in order to assess hoof balance.
EIPH: postrace endoscopic evaluation of Standardbreds and Thoroughbreds
Authors: BIRKS E. K. , SHULER K. M. , SOMA L. R. , MARTIN B. B. , MARCONATO L. , DEL PIERO F. , TELEIS D. C. , SCHAR D. , HESSINGER A. E. , UBOH C. E. 
Published: June 2010

SummaryThe incidence and severity of exercise‐induced pulmonary haemorrhage (EIPH) in the 2 most commonly raced horse breeds, Thoroughbreds (TB) and Standardbreds (STD), were studied, with particular interest in the possible influence of frusemide (F) and/or the breed (or running gait) on EIPH. The appearance of blood within the trachea was semi‐quantified using a published 5‐point system, with zero assigned when no blood was observed, and numbers 1–4 assigned with increasing amounts of blood. Considering each endoscopic examination as a separate event, approximately 75% of the postrace endoscopic examinations had blood‐scores of 1, 2, 3, or 4, regardless of breed or F administration. For horses examined twice, the chances of finding blood‐scores of 1 or greater in either of the examinations increased to approximately 95%. All horses examined 3 or more times had endoscopic blood‐scores of 1 or greater following one or more races, again, irrespective of the breed or F administration. Mean ± s.e. ‘blood scores’ were 1.5 ± 0.1 and 1.8 ± 0.2 for TB, and 1.4 ± 0.2 and 1.2 ± 0.1 for STD racing with and without prerace F, respectively. Therefore, there was no apparent effect of breed (or possibly racing gait) on EIPH, and no differences in the incidence or severity of EIPH were observed between horses with or without prerace frusemide administration.
Effect of dorsal displacement of the soft palate on ventilation and airflow during high‐intensity exercise
Authors: FRANKLIN S. H. , NAYLOR J. R. J. , LANE J. G. 
Published: June 2010

SummaryDorsal displacement of the soft palate (DDSP) is one of the most common obstructive conditions of the upper respiratory tract in the racehorse. The present study was conducted to determine the effects of intermittent dorsal displacement of the soft palate (DDSP) on ventilation and respiratory airflow during high intensity exercise. Videoendoscopic recordings were made of the nasopharynx and larynx simultaneously with measurements of airflow and respiratory gas exchange, during high‐speed treadmill exercise in 9 horses with confirmed intermittent DDSP admitted for clinical investigation of poor racing performance.In all horses, DDSP resulted in a reduction in minute ventilation (VE) (P<0.001), associated with a decrease in tidal volume (VT) (P<0.01) with no change in breathing frequency (f) and a reduction in oxygen consumption (V̇O2) (P<0.01). Further, DDSP resulted in reduction of expiratory flow parameters, including peak expiratory flow (PEF), EF50, EF25and EF12.5(P< 0.01), with no alteration of inspiratory flow. These results confirm that naturally‐occurring intermittent DDSP creates a flow‐limiting expiratory obstruction. The associated impairment of athletic performance is probably caused, at least in part, by the accompanying decrease of oxygen uptake.
Physiological measurements and upper and lower respiratory tract evaluation in French Standardbred Trotters during a standardised exercise test on the treadmill
Authors: COUROUCÉ‐MALBLANC A. , PRONOST S. , FORTIER G. , CORDE R. , ROSSIGNOL F. 
Published: June 2010

SummaryThere are a variety of reasons for poor performance in racehorses. Exercise intolerance has often been associated with subclinical respiratory abnormalities, and diagnostic aids are therefore used to enhance clinical detection. Physiological variables can also be measured in order to evaluate the metabolic reponse to exercise. This study evaluated the relationship between physiological measurements and upper airway videoendoscopy during a standardised treadmill exercise test and bronchoalveolar lavage (BAL) cytology in control horses (good racing performance, n = 14) and poor performers (n = 27). The poor performers were divided into 2 groups:Group 1= both upper and lower respiratory airway abnormal findings (n = 10);Group 2= lower respiratory airway abnormal findings (n = 17). Horses inGroup 2were divided into 3 categories:Group 2A= exercise‐induced pulmonary haemorrhage (EIPH; n = 5);Group 2B= small airway inflammation (SAI ± EIPH; n = 7) andGroup 2C= other (n = 5). During exercise, the poor performers had significantly lower arterial Pao2and higher HR and blood lactate concentrations compared to controls. Total nucleated cell count of BAL fluid collected from poor racing performers was significantly higher than in controls; also, epithelial cells and haemosiderophage percentage collected from poor racing performers were significantly higher than in controls. Eight horses with dorsal displacement of the soft palate also had eytological evidence of lower respiratory airway disease. The results of this study suggest that there is a significantly different metabolic response (HR, blood lactate, Pao2) to exercise in poor compared to good performers. As both upper and/or lower respiratory problems can be associated with poor racing performance, a detailed examination of the upper and lower respiratory tracts at rest, during and after exercise is advised.
Airway cooling and mucosal injury during cold weather exercise
Authors: DAVIS M. S. , LOCKARD A. J. , MARLIN D. J. , FREED A. N. 
Published: June 2010

SummaryIn human subjects that exercise strenuously in cold weather, there is evidence that hyperventilation with cold air leads to peripheral airway cooling, desiccation and mucosal injury. Our hypothesis was that hyperventilation with cold air can result in penetration of unconditioned air (air that is not completely warmed and humidified) into the peripheral airways of exercising horses, resulting in peripheral airway mucosal injury. To test this hypothesis, a thermister‐tipped catheter was inserted through the midcervical trachea and advanced into a sublobar bronchus in three horses that cantered on a treadmill at 6.6 m/s while breathing cold (5°C) air. The mean (± s.e.) intra‐airway temperature during cantering was 33.3 ± 0.4°C, a value comparable to the bronchial lumen temperatures measured in man during maximal exercise while breathing subfreezing dry air. In a second experiment, 6 fit Thoroughbred racehorses with satisfactory performance were used to determine whether strenuous exercise in cold conditions can produce airway injury. Horses were assigned to Exercise (E) or Control (C) groups in a random crossover design. Samples of bronchoalveolar lavage fluid (BALF) in the E treatment were recovered within 30 min of galloping exercise in 4°C, 100% relative humidity (E), while in C BALF samples were obtained when the horses had not performed any exercise for at least 48 h prior. Ciliated epithelial cells in BALF were higher in E than in the C treatment. Similar results have been found in human athletes and laboratory animal models of cold weather exercise. These results support the hypothesis that, similar to man, horses that exercise in cold weather experience peripheral airway mucosal injury due to the penetration of unconditioned air.Furthermore, these results suggest that airway cooling and desiccation may be a factor in airway inflammation commonly found in equine athletes.
Effect of instillation into lung of autologous blood on pulmonary function and tracheobronchial wash cytology
Authors: ART T. , TACK S. , KIRSCHVINCK N. , BUSONI V. , VOTION D. , FREEMAN K. , LEKEUX P. 
Published: June 2010

SummaryThis study aimed at measuring the functional consequences and the pulmonary cytology changes following a simulation of pulmonary haemorrhage. Pulmonary function tests including lobeline‐induced hyperventilation, cytology of tracheo‐bronchial wash (TBW) and thoracic radiographs were performed before, as well as 1, 7, 14 and 28 days after, the instillation of 300 ml of blood into the lungs of 4 horses deemed free of exercise‐induced pulmonary haemorrhage (Group 1). Control data (Group 2) were obtained by instilling the same volume of saline into the lungs of the same horses in a crossover design (control). The instillation of blood or saline resulted in an increase in the number of neutrophils in the TBW. Thoracic radiographs showed increased opacity in the caudodorsal region of the lungs in 4/4 (Day 1) and 2/4 horses (Day 7), inGroup 1, and in 2/4 (Day 1) and 0/4 horses (Day 7) in the control group. These changes were attributed to the instillation procedure rather than the nature of the instilled material. Breathing mechanics and arterial blood gases at rest were not affected in eitherGroups 1or2. However, the maximal expiratory peak flow recorded during lobeline‐induced hyperventilation was significantly lower (P<0.05) and the total pulmonary resistance significantly higher (P<0.05) on Day 1 inGroup 1, but notGroup 2. These observations suggest that expiratory flows might be partly limited in bleeders when breathing at high airflow.
Alveolar fibrosis and changes in equine lung morphometry in response to intrapulmonary blood
Authors: MCKANE S. A. , SLOCOMBE R. F. 
Published: June 2010

SummaryNecropsy studies of horses suffering exercise‐induced pulmonary haemorrhage (EIPH) have identified mild inflammatory lesions with evidence of alveolar fibrosis and bronchiolitis. These lesions were thought to be the result of viral infections that predisposed the affected regions of the lung to EIPH. We have shown previously that during erythrophagocytosis in the alveolar space, there is a prolonged period of macrophage influx and activation. This present study used morphometric analysis to quantify the effects of macrophage activity during erythrophagocytosis, on the alveolar cell population and physical structure of the alveolar walls. Segments of the bronchial tree were inoculated with either autologous whole blood or serum, at 15, 8, 3 days, 24 h and 30 min prior to euthanasia. Blood inoculation produced many significant changes in the alveolar morphometry including, increased numbers of alveolar macrophages, increased septal thickness, and a markedly increased percentage of collagen in the alveolar walls. Signs of chronic inflammation including increased macrophage activity and erythrophagocytosis coincided with increased alveolar macrophage numbers (10,688 ± 1708 cells/mm3to 30,957 ± 6831 cells/mm3), septal thickness (4.1 ± 0.4 μm to 6.1 ± 0.5 μm) and alveolar septal collagen content (6.6 ± 0.5% to 27.5 ± 3.3%). The results suggest that intrapulmonary blood induces a macrophage dominated inflammatory response, septal thickening and the development of alveolar fibrosis. These changes are the probable cause of the observed alveolar fibrosis and bronchiolitis that was once suspected to be the originating cause of EIPH.
Right ventricular pressure dynamics during exercise: relationship to stress echocardiography
Authors: DURANDO M. M. , REEF V. B. , BIRKS E. K. 
Published: June 2010

SummaryThorough evaluation of myocardial function remains difficult to evaluate under exercising conditions. This study described right ventricular (RV) pressure dynamics during and immediately following exercise. Nine Thoroughbreds without evidence of cardiac disease completed treadmill exercise at 110% of the speed necessary to elicit V̇O2maxwhile RV pressures were recorded. RV pressure dynamics were calculated at rest, maximal speed and at 10 s intervals for 2 min after exercise. Stress echocardiography was performed at rest and within 120 s after exercise. Mean dP/dtmax and dP/dtmin values were significantly greater at maximal speed and up to 30 s immediately postexercise than at rest and all time points from 60 to 120 s postexercise. Mean dP/dtmax and dP/dtmin were not significantly different from resting values after 60 s postexercise. Tau (the time constant for ventricular relaxation) decreased significantly with exercise, but was not significantly different from rest at time points from 60 to 120 s following exercise. Mean % fractional shortening (FS) increased postexercise; however, the coefficient of variability was large. Wall motion indices also showed large variability postexercise. These temporal changes in normal horses suggest that exercising RV pressure dynamics may provide a better estimation of cardiac function during exercise than postexercise stress echocardiography.
Relationship between body composition, blood volume and maximal oxygen uptake
Authors: KEARNS C. F. , McKEEVER K. H. , JOHN‐ALDER H. , ABE T. , BRECHUE W. F. 
Published: June 2010

SummaryIt has long been known that body mass and, more specifically, lean body mass are strongly correlated with maximal oxygen uptake (V̇O2max) in man and animals. However, there are no data to date describing this phenomenon in the horse. The purpose of this paper is to examine the relationship between body composition and V̇O2maxin the horse. Twenty‐three healthy and unfit Standardbred mares performed an incremental exercise test (GXT) to measure V̇O2max. Rump fat thickness (RTH), a measure of fat covering, was measured using B‐mode ultrasound. Plasma volume, total blood volume and red cell volume were determined, using the Evan's Blue dye dilution technique and packed cell volume. V̇O2maxwas correlated with body mass (r = 0.541; P<0.01) and exercise haematocrit (exHCT; r = 0.407; P<0.05) but not RTH or the other haematological variables. To eliminate the influence of body mass on the individual variables, a regression analysis was performed on the mass‐residuals of V̇O2max, RTH, plasma volume and exHCT. The residuals of V̇O2maxwere correlated negatively with the residuals of RTH (r = −0.687; P = 0.0003) and positively with the residuals of exHCT (r = 0.422; P = 0.045) but not plasma volume. V̇O2maxcould be predicted from a linear combination of the residuals of RTH and exHCT (r = 0.767; P<0.0001). These data indicate that V̇O2maxin the horse is significantly related to fat‐free mass (FFM), independent of body mass. Red blood cells from the splenic reserve constitute an important factor in the horse's ability to achieve a high V̇O2max. Therefore, lean body mass may be a more appropriate basis for assessing metabolic function in the athletic horse.
Effect of NaCI and NaHCO3on serum ionised calcium and blood gas status during sprinting
Authors: BEARD L. A. , HINCHCLIFF K. W. 
Published: June 2010

SummarySodium bicarbonate is often administered to horses before racing in an attempt to delay fatigue and improve performance. We examined the effect of acid‐base status on serum ionised calcium concentration (iCa) during high intensity exercise in 8 Standardbred mares. In a randomised, blinded, cross‐over study, mares were administered each of 3 treatments, NaCl (0.7 g/kg bwt), NaHCO3(1 g/kg bwt) in 3 l water, or 3 l of water only, 4 h before performing a standardised exercise test to fatigue on a treadmill. Mixed venous blood samples were collected as the horses ran for 5 min at 3 m/s, to fatigue at a predetermined speed (approximately 113% V̇O2max) and for 5 min at 3 m/s. There was no effect of treatment on time to fatigue (P = 0.744). NaHCO3attenuated (P<0.05) the exercise‐induced decrease in venous pH (mean ± s.e. 6.97, 6.95 and 7.06 ± 0.02 at end of sprint for water, NaCl and NaHCO3, respectively). Both serum total calcium concentration (tCa) and iCa increased (P<0.05) with running. NaHCO3decreased iCa (P<0.05) compared to water; iCa of 1.58 and 1.44 ± 0.04 mmol/l before exercise and 1.69 and 1.49 ± 0.05 end sprint, for water and NaHCO3treatments, respectively. These results demonstrate an effect of NaHCO3on iCa during exercise. Further study is necessary to determine the effect of alterations in iCa on exercise performance.