bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of Motion During Manipulation of the Equine Pelvis
Authors: Goff L , Van Weeren P , Jeffcott L , McGowan C
Published: June 2014

Introduction

Manipulation of the equine ilium and sacrum is utilised to assess range of motion at the SIJ. Motion of the ilium and sacrum during manual force application to the equine pelvis has been measured previously in vitro. The aim of this study was to measure the amount and direction of motion in vivo including comparison of bone fixated and skin mounted sensors.

Methods

Orientation sensors were skin‐mounted over tuber sacrale (TS) and 3rd sacral spinous process (SP) of six standing Thoroughbred horses. Orientations of each TS and sacrum were recorded by one investigator during six trials of manual force applied to the pelvis, inducing cranial, caudal and oblique rotations. The study was repeated with the sensors mounted onto pins implanted into TS and SP. Mean values were reported in Euler angles for the three orthogonal planes lateral bend (LB), flexion‐extension (F‐E) and axial rotation (AR). Correlation between skin and bone fixated markers (Spearman R) was determined with significance set at P<0.05.

Results

The largest mean values recorded during rotations applied to the pelvises were for F‐E (2.08 ± 0.35o) with bone fixated sensors. Axial rotation gave the largest values recorded with skin‐mountings (1.70 ± 0.48o). There was poor correlation between skin‐mounted and bone implanted markers.

Conclusions

Bony kinematics during external movement applied to the pelvis cannot be predicted from skin‐mounted sensors, due to differences between skin‐ and bone‐mounted sensors. Manipulation of the equine pelvis can be expected to produce motion in the plane of F‐E, but axial movement should be interpreted with caution due to the potential effects of skin motion.

Ethical Animal Research

Ethical approval for animal use was obtained by the institutional animal ethics committee (University of Queensland). Sources of funding: Rural Industries Research and Development Council, Australia. Competing interests: none.
Thoracolumbar Flexion‐Extension During Water Treadmill Walking
Authors: Nankervis K , Entwistle L , Gervaise‐Brazier S , Earl S , Twigg‐Flesner A
Published: June 2014

Introduction

Water treadmill exercise is used for rehabilitating horses with back dysfunction, yet little is known about the effect of this type of exercise on back movement.

Methods

8 horses walked in water level with the hoof, fetlock, hock and stifle. Reflective markers over the dorsal spinous processes of T6, T10, T13, T18, L3, L5 and S3 and left and right tuber coxae were used to measure flexion‐extension range of movement (F‐E ROM) around T10, T13, T18, L3 and L5, vertical displacement of the pelvis (Pelvic ROM) and vertical distance between T13 and L5 (lowest and highest point of the back). 3D coordinates were tracked using ProReflex cameras. 5–9 strides were analysed for each horse at each water height. Repeated measures ANOVA and post hoc tests were used to determine differences in measured variables between water heights (P < 0.05).

Results

Peak flexion of T10, T13, T18 and L3 occurred in hock height water. Peak extension of T18, L3 and L5 occurred in stifle height water without a significant difference in F‐E ROM between water heights (P>0.05). Pelvic ROM was greatest in stifle height water, with no significant difference between water heights. The vertical distance between T13 and L5 was greatest in stifle height water (P<0.05 between hoof and hock height water) as a result of an elevation of L5 relative to T13.

Conclusions

As water height increases L5 is elevated relative to T13, increasing the tendency for extension of the thoracolumbar spine. To maximise thoracolumbar flexion and avoid extension, water at hock height is more beneficial then stifle height water.

Ethical Animal Research

Project approved by Hartpury College Research Ethics Committee. Sources of funding: Hartpury College. Competing interests: none.
The Innate Immune Response in the Airways and in Blood is Altered by Training in Horses
Authors: Frellstedt L , Waldschmidt I , Dupuis‐Tricaud M , Lekeux P , Art T
Published: June 2014

Introduction

Lower airway diseases are common problems in sports and racing horses. In humans, exercise causes increased susceptibility to respiratory infections associated with down‐regulated expression of Toll‐like receptors (TLRs), co‐stimulatory and antigen‐presenting molecules. Because numerous cell types are implicated in important defense mechanisms against airborne infections, we aimed to assess the effect of training on innate immune responses of pulmonary alveolar macrophages (PAM), equine bronchial epithelial cells (EBEC) and blood monocytes.

Methods

PAM, EBEC and monocytes were collected at rest and after a standardized exercise test (SET) from eight untrained, trained and deconditioned horses. We compared their respective expression of TLR1‐9 by qPCR and their cytokinic responses following exposure to various TLR ligands by ELISA. Data were reported as least square means and analyzed by a global linear mixed model.

Results

The mRNA expression of TLR3 was down‐regulated by training in PAM (P<0.0001) and monocytes (P<0.015), whereas the mRNA expression of TLR4 was up‐regulated in monocytes (P = 0.0004) only. Monocytes stimulated with TLR2‐ and TLR4‐ligands showed increased cytokine secretion after training and deconditioning (P<0.025). EBEC from trained horses produced less TNF‐alpha (P<0.05) after treatment with ligands of TLR2 and TLR3 compared with EBEC from untrained horses. The production of TNF‐alpha (P<0.001) and IFN‐beta (P<0.001) in non‐stimulated and stimulated PAM was decreased in trained and deconditioned horses.

Conclusions

The impaired cytokine production in PAM and EBEC after a training period might explain the increased susceptibility to respiratory viral infections and is associated with the activation of cells at the systemic level.

Ethical Animal Research

This work was approved by the Animal Ethics Committee of the National Veterinary School of Alfort (agreement number: 13/12/11‐9). Sources of funding: Hippolia Foundation, the Conseil Regional de Basse‐Normandie, the European Regional Development Fund and the Fonds unique interministeriel. Competing interests: none.
Heart Rate Recovery Time in Exercise Testing of Endurance Horses
Authors: Madsen MF , Kanters JK , Buhl R
Published: June 2014

Introduction

Endurance horses must attain heart rates below a certain limit (usually 64 beats/min) to pass veterinary inspections in endurance rides. The time necessary for heart rate recovery is therefore important in this equestrian discipline. The objective was to determine heart rate (HR) and heart rate recovery time (HRtime) of endurance horses exercised at various velocities.

Methods

Twelve Arabian endurance horses completed an incremental field exercise test with concurrent ECG‐recording. Horses were actively competing at distances of 80–160 km. The exercise protocol defined five intervals with intended velocity range of 11–13 km/h, 15–17 km/h, 18–20 km/h, 21–25 km/h, and >25 km/h, respectively. Each interval was terminated by a halt lasting until HR declined to 64 beats/min. Velocity was determined by a global positioning system, while HR and HRtime were calculated from the ECG. Descriptive statistics was performed.

Results

Velocity, HR and HRtime (as mean ± SD); Interval 1: 12.4 ± 0.9 km/h, 104 ± 11 beats/min, 50 ± 34 s; Interval 2: 15.9 ± 0.5 km/h, 120 ± 9 beats/min, 128 ± 81 s; Interval 3: 20.0 ± 0.6 km/h, 133 ± 10 beats/min, 202 ± 120 s; Interval 4: 22.9 ± 1.0 km/h, 140 ± 11 beats/min, 264 ± 170 s; and Interval 5: 29.3 ± 3.8 km/h, 171 ± 15 beats/min, 341 ± 187 s. HR showed linear correlation with velocity. HRtime varied between horses especially after greater velocities, with a tendency of being shortest in the best performing horses. Four outliers of HRtime were excluded from horses reluctant to stand still during the halt due to anticipatory excitement.

Conclusions

Heart rate recovery time shows great individuality and could potentially be used as a performance indicator in endurance horses. Possible fluctuations of HR due to anticipatory excitement during the halt may prolong HRtime and must be accounted for.

Ethical Animal Research

Explicit owner informed consent for participation in this study is not stated. Sources of funding: University of Copenhagen. Competing interests: None.
Field Survey on Fetlock Problems in Young Horses
Authors: Morgan K , Kanstrup A , Rundgren M
Published: June 2014

Introduction

Problems in the musculoskeletal system are the most common reason for impaired function and culling in insured riding horses in Sweden. Impaired function of the fetlock, e.g. arthritis, is a believed to be a multi‐factorial problem. The aim of the pilot study was to find factors associated with problems in the fetlock.

Methods

This study focused on horses 5–7 years with fetlock problems. A questionnaire on training and management (feeding, housing, shoeing) was sent to 200 horse‐owners with insurance policies on their horses; 100 had claimed insurance compensation for problems in the fetlock (I‐horses) and 100 owners had healthy horses that served as controls (C‐horses). The results of the proportions in each group were compared with a Chi‐squared test. The response rate was 42%.

Results

The results showed significant differences for training‐related factors but not for management‐related factors. The healthy C‐horses were ridden for a longer period of time at each occasion (58.5 minutes per day) compared to I‐horses (51.3 minutes per day) (P = 0.043). The C‐horses jumped once a week and the I‐horses 0.5 times per week (P = 0.0075). There was a tendency for shorter period of training free weeks to be beneficial (C‐horses 4.0 weeks, I‐horses 5.5 weeks per year; P = 0.083). A larger proportion of the I‐horses participated in the Swedish Riding Horse Quality Test for four‐year old horses (P = 0.043).

Conclusions

The results indicated that training‐related factors were associated with whether a horse remained healthy or not. Further studies on training and educational systems of young horses are needed to prevent impaired function.

Ethical Animal Research

No animals were used in the study. Sources of funding: This study was financed by the insurance company ‘Agria’ which approved submission of the results for presentation and publication in conjunction with ICEEP 9. Competing interests: none.
Effects of Different Exercise Intensities During Detraining on Aerobic Capacity in Thoroughbred Horses
Authors: Mukai K , Hiraga A , Takahashi T , Ohmura H , Jones JH
Published: June 2014

Introduction

Thoroughbred racehorses often experience periods of detraining due to locomotor disorders and subsequent rehabilitation. We hypothesised that regularly exercising horses at different intensities during a period of detraining would differentially maintain their cardiopulmonary and O2 transport capacities.

Methods

Twenty‐seven Thoroughbred horses trained for 18 weeks then underwent 12 weeks of detraining according to one of three protocols: 1) cantering at 70% maximal rate of O2 consumption (VO2max) for 3 min/d for 5 d/wk (C group), 2) walking for 1 h/d for 5 d/wk (W group) and 3) stall rest (S group). Standardised treadmill exercise tests were performed before and after detraining during which cardiopulmonary and O2 transport variables were measured. Data were analysed with two‐way ANOVA and pairwise comparisons made with Tukey's test. Significance was defined as P≤0.05.

Results

Mass‐specific VO2max, maximal cardiac output and maximal stroke volume of all groups decreased after detraining with no differences between groups. The run time to exhaustion, speed eliciting VO2max, speed eliciting maximal heart rate and speed at which plasma lactate concentration reached 4 mmol/l of the C group did not change but those of the W and S groups decreased after detraining. Arterial‐(mixed‐venous) O2 concentration difference did not change after detraining in any group, and maximal heart rate decreased in the W and S groups.

Conclusions

These results suggest it may be possible to identify a minimum threshold exercise intensity or protocol during detraining in horses that maintains significant elements of performance‐related variables and minimises reductions in O2 transport capacity.

Ethical Animal Research

Protocols for the study were approved by the Animal Welfare and Ethics Committee of the Japan Racing Association (JRA) Equine Research Institute. Sources of funding: Japan Racing Association. Competing interests: none.
Young Friesian Horses Show Familial Aggregation in Fitness Response to a 7‐Week Performance Test
Authors: Munsters C , van den Broek J , van Weeren R , Sloet van Oldruitenborgh‐Oosterbaan M
Published: June 2014

Introduction

The aims of the study were to monitor fitness level of young Friesian horses and to assess whether fitness data has a predictive value for the final performance score and whether familial aggregation of response to training could be detected.

Methods

Sixty‐six young Friesian horses, offspring of six different stallions (A, B, C, D, E and F), underwent a 7‐week performance test. Horses were given a performance score for their dressage ability (0–110 points), and fitness was evaluated with standardised‐exercise‐tests (SET) at the beginning (SET‐I) and the end (SET‐II) of the period. Heart rate (HR; beats/min) was measured in both SET, and plasma lactate concentration (LA; mmol/L) was measured only in SET‐II. The majority of data were analyzed with an ANOVA‐test or a linear‐model (P<0.05).

Results

Fitness of horses improved significantly between SET‐I and II (P = 0.015). There was a large heterogeneity in responsiveness to training; some horses were high‐responders, whereas others were non‐ or low‐responders. There was a familial aggregation of HRcanter‐1 response to training (P = 0.039); offspring of stallion C decreased significantly more in HR than offspring of stallions A (P = 0.09), D (P = 0.013) and F (P = 0.009). HR had no predictive value for the performance score, but horses that did not reach the anaerobic threshold in SET‐II scored significantly better (73.8 ± 5.6 points) than horses that did (69.9 ± 5.9 points, P = 0.025).

Conclusions

The present study reports, for the first time in the horse, familial aggregation of HR‐response to training. HR could not predict final performance score, but LA‐concentrations during SET‐II were predictive.

Ethical Animal Research

Consent was obtained from the owners of all horses. Sources of funding: partly financially supported by the Royal Friesian Horse Studbook (KFPS). Competing interests: none.
Subjective Evaluation of Muscle Conformation in Horses Subjected to Pace Training or not
Authors: Ragnarsson S , Jansson A
Published: June 2014

Introduction

Muscle conformation is often discussed among practitioners and it is sometimes suggested that specific training strategies affect muscle conformation. This study attempted to investigate; 1) if it is possible for practitioners to judge whether a horse is subjected to pace training or not based on subjective analysis of hind‐end muscle conformation and 2) which terminology practitioners would use when doing this.

Methods

Photos were taken from behind (transverse plane) in 10 Icelandic horses trained for mounted pace racing and 11 used for riding but not pacing. Body condition score was 7.4 and 7.5 (SE 0.3, P>0.05) in pacers and non‐pacers, respectively (9 degree scale, ANOVA, Tukey test). Three experienced horse practitioners (A, B, C) were informed that the 21 photos showed horses trained for pace racing and horses not trained as pacers and they were instructed to separate photos into two groups based on their subjective impression of muscle conformation.

Results

Practitioner A divided horses into groups called “even” (n = 13) and “narrow” (n = 8); B into groups called “strong” (n = 11) and “weak” (n = 10); and C into “high” (n = 9) and “wedged” ” (n = 12). The practitioners assumed that “even”, “strong” and “high” horses were pacers and 10, 10 and 12 observations were correct in practitioner A, B and C, respectively (mean ± SD: 51 ± 5%). The number of cases where all practitioners agreed and grouping also matched pacers and non‐pacers were 7.

Conclusions

It appears not to be possible to judge whether an Icelandic horse is pace trained based on observations of the hind‐end musculature. The terminology used appeared to refer either to the conformation or to a presumed strength.

Ethical Animal Research

Explicit owner informed consent for participation in this study is not stated. Sources of funding: Holar University College, Iceland. Competing interests: none.
Effects of Amount of Intensive Training on VLa4 in 3‐Year Old Standardbred Horses
Authors: Ringmark S , Hedenström U , Lindholm A , Jansson A
Published: June 2014

Introduction

The effects of different amounts of training on performance of young horses have not yet been studied in a long term perspective. The aim of this study was therefore to assess the effect on VLa4 of two training programs performed from the age of 2 to 3 in Standardbred horses.

Methods

Fourteen horses were in March as 2‐year olds divided into two groups; one was randomized to a training program including intensive exercise (control) and the other to a training program with reduced amount of intensive exercise (distance −30% compared to control). Group division was partly based on breeding index (means: control 110, reduced 109) and gluteus medius fiber type ratio (IIA/IIB, both groups mean 1.34). Horses were trained ∼2 times/week. After 14 months, a VLa4‐test was performed on a track (4 x 1000 m). Speed was measured by GPS and increased by ∼3 s/1000 m for every interval. Blood samples were collected after each interval and lactate concentration was determined using Lactate Pro. Exponential regression analysis of speed and lactate concentration were used to estimate individual VLa4. ANOVA and Tukey's test were used to analyse differences between groups.

Results

There was no difference in VLa4 between the control and reduced exercise group (10.6 ± 0.1 and 10.8 ± 0.1 m/s).

Conclusions

The study indicates that it might be possible to reduce the amount of intensive training by ≤30% without impairing performance of 3 year old Standardbred horses.

Ethical Animal Research

The study was approved by the local ethics committee in Umeå. Sources of funding: Swedish University of Agricultural Sciences, Swedish National Trotting School at Wången, Swedish Trotting Association, Swedish Horse Council Foundation, Swedish Horse Racing Totalisator Board (ATG), Trioplast AB, Dow Chemicals, Polar Sverige AB, and Scandivet AB. Competing interests: none.
Effect of Conditioning Horses with Runs of 100 Meters at Near Maximal Speed Alone or in Combination with Low Intensity Exercise
Authors: Signorini R , di Lascio N , Brero L , Genolet J , Lindner A
Published: June 2014

Introduction

Exercising horses one, two, or three times per week during 6 weeks using two intervals with near‐maximal speed over 100 m elicited a decrease of VLa4, a widely accepted parameter of fitness and competitive success of horses (speed at which, under defined conditions, the blood lactate concentration reaches 4 mmol/l). Therefore, two field studies were performed to examine the possibility of avoiding decline in VLa4 with this type of exercise.

Methods

Study 1) 6 horses were submitted to the same exercise as above once per week during the first 2 weeks of a conditioning period (CP) adding one interval in each exercise session every 2 weeks for the following 6 weeks. Study 2) 6 horses did the same as horses in study 1 plus once per week an exercise bout at their individual VLa2 during 35 minutes. Before, every 2 weeks during, and 2 weeks after the CP, horses were subjected to standardized exercise tests to determine their VLa4 (and VLa2 where convenient) and maximal speed (speedmax). The effect of conditioning on VLa4 and speedmax was examined using two‐way repeated measures analysis of variance and Fisher's test.

Results

In study 1 mean VLa4 declined during the first 4 weeks of CP but increased to the initial level thereafter (P<0.05) while speedmax remained the same over time. In study 2 VLa4 decreased continuously (P<0.01) while speedmax increased (P<0.01).

Conclusions

The results might be important to train horses racing over different distances.

Ethical Animal Research

All procedures were approved by the Bioethical Committee of the University Nacional del Litoral, Esperanza, Argentina. Sources of funding: Verein zur Förderung der Forschung im Pferdesport, Germany, AVIGAN Alimentos Balanceados and Pellfood. Competing interests: none.
Evaluation of Masks for Field Testing of Exercising Horses
Authors: Sides R , Bayly W , Kirkpatrick R , Renner E , Gough K , Katz L , Evans D
Published: June 2014

Introduction

The ability to accurately assess equine oxygen consumption (VO2) under field conditions has been limited by the need for unrestricted gas exchange.

Methods

Two variations of a mask and an associated electronics control module (ECM) were designed to enable breath‐by‐breath measurement of airflows with two 8.0 cm diameter pneumotachometers located 7.5 cm in front of each narus and connected to differential pressure transducers mounted on the outside of the mask. The ECM was comprised of electronics for signal filtering to the flow transducers, an oxygen sensing cell, and an analog‐to‐digital converter all powered by a lithium‐ion battery. The battery also powered a pump connected to gas sampling ports between the nares and pneumotachometers. Airflow and oxygen content of inspired and expired gases were recorded through the ECM and electronically transferred to a notebook. VO2 was determined from these recordings by an operator using a customized software analysis program. One mask encased the lower head (E). The other left the jaw free so horse could wear a bit and be ridden (R). Multiple treadmill exercise tests were undertaken by 6 horses to measure VO2max and blood gases. Each mask was worn twice and results compared to those from an open flow‐through system (O) by 2‐way RMANOVA (P<0.05). Utility of the system was evaluated using the intraclass correlation coefficient of 4 independent raters.

Results

Blood gases and VO2max (152.0 ± 4.0 (mean ± SEM; O), 147.7 ± 4.3 (E), 150.7 ± 3.3 (R) ml/(kg.min) were not different between masks. VO2 measures were reproducible for each mask. Agreement between the 4 raters was excellent (intraclass correlation coefficient = 0.99).

Conclusions

Masks capable of measuring VO2 during field exercise were developed, tested and found accurate by multiple users.

Ethical Animal Research

Studies performed were approved by the Institution's Animal Care and Use Committee (protocol #3807). Sources of funding: Institutional sources. Competing interests: Washington State University has filed notice of its intent to apply for a patent for facemask used in this study.
Quantifying Warm‐Up in Showjumping Horses Over 3 Consecutive Days
Authors: Tranquille C , Walker V , Hodgins D , Goosen T , McEwen J
Published: June 2014

Introduction

The objective was to quantify warm‐up (WU) jumping patterns/duration in showjumping horses.

Methods

Ten mixed breed horses (9.1 ± 1.9 yrs) were assessed at a British Equestrian Federation (BEF) World Class Performance three day training session. Riders received coaching during WU and after jumping a 15 fence (1.35–1.45 m) course once on day‐1 and twice on day‐2; on day‐3 the second round was an 8 fence jump‐off. Fence type/height, number of jumping efforts (JE) and lead take‐off/landing limbs during WU were recorded. Rider global‐positioning‐system recorded speed. Inertial motion sensors fixed to the lateral aspect of metatarsal/metacarpal bones, recorded time spent in each pace/rein plus stride length (SL) during WU and course. Paired Students T‐tests were used to compare variables between days, as well as WU and course.

Results

Mean WU duration, time in each pace and on each rein did not differ within rider between days, however there were inter‐rider differences (mean WU duration = 18 mins; range = 12–27 mins). Number of JE and fence type/height did not differ between days. During WU, there was marked canter lead, jump landing and leaving lead limb asymmetry (left canter lead predominating in all cases). There was no preference in canter lead when approaching WU fences. Horses cantered slower and with a shorter SL during WU compared to when jumping the course (speed‐WU:4.21 ± 0.09 m/sec; course:5.53 ± 0.15 m/sec; SL‐ WU:2.59 ± 0.06 m; course:3.16 ± 0.08 m).

Conclusions

Results provide preliminary information on WU duration, and suggest that showjumping horses may WU asymmetrically, predominately on the left rein, at competitions and during training. This could have implications for injury risk to a particular forelimb or hindlimb in showjumping horses.

Ethical Animal Research

Explicit owner informed consent for participation in this study is not stated. Sources of funding: The World Class Development Programme is funded by the Department for Culture, Media and Sport, through Exchequer and National Lottery funds, via UK Sport. Competing interests: none.
Role of The CO2 System in Regulating Intramuscular Hydrogen Ion Concentration during Exercise in Horses
Authors: Vengust M , Richards J , Staempfli H , Viel L , Heigenhauser G
Published: June 2014

Introduction

Elimination of CO2 from skeletal muscle (mCO2) during exercise is important for the regulation of intramuscular [H+] ([mH+]). Carbonic anhydrase (CA) catalyses the hydration/dehydration reaction of CO2 to facilitate its elimination. We hypothesised that extracellular CA inhibition and subsequent increase in PCO2 will result in increased m[H+] and decreased exercise performance.

Methods

Six horses were exercised on a treadmill until fatigue without (Con) and with acetazolamide (CA inhibitor) treatment (Acz; 30 mg/kg, 30 min before exercise). Arterial and mixed‐venous blood was sampled, and biopsies collected from gluteal muscles at fatigue. Whole blood (wb) arteriovenous difference across the muscle (a‐v) of [Na+], [K+], [Cl−], [Lac−], [SID], and PCO2, mCO2 and m[H+] were determined. Paired t‐test was used to assess statistical significance (P<0.05).

Results

Duration of exercise to fatigue was not affected by Acz. Compared to Con, Acz increased mCO2 (Con 16.5(mean) ± 3.6(SE), Acz 20.5 ± 2 mmol/L) and mixed‐venous and arterial PCO2 but had no effect on VCO2. No difference was observed in m[H+] between Con (118 ± 18 nmol/L) and Acz (99 ± 16 nmol/L). Acetazolamide did not affect plasma [H+]. Based on the a‐v differences Acz increased [Na+]wb and [K+]wb release, increased [Cl‐]wb uptake and did not affect [Lac‐]wb release by the muscle. Acz decreased a‐v[SID]wb (Con 6.2 ± 2.8 mmol/L, Acz −0.3 ± 2 mmol/L).

Conclusions

Although PCO2 and mCO2 were elevated no difference in [mH+] was observed. An increase in m[H+] due to elevated mCO2 was attenuated by strong ion fluxes between intramuscular and vascular spaces. Strong ion exchanges are important in attenuating m[H+] and maintaining exercise performance.

Ethical Animal Research

The study protocols were approved by the Animal Care Committee of the University of Guelph according to the Guide to the Care and Use of Experimental Animals (Canadian Council on Animal Care, Ottawa, Ontario). Sources of funding: Ontario Ministry of Agriculture and Food ‐ Equine Program, Department of Clinical Studies at the University of Guelph, Canadian Institutes of Health Research and the Slovenian Research Agency grant P4‐0053. Competing interests: none.
Genetic Component of Endurance Ability
Authors: Younes M , Robert C , Cottin F , Barrey E
Published: June 2014

Introduction

Arabian horses have the best records in long distance endurance racing (80–160 km). The endurance horses are interesting models to calculate the heritability (h2) of exercise ability. Heritability indicates the percentage of trait transmitted by parents to their descendants (h2 = Genetic variance/Total variance). In human athletes, heritability of physiological traits calculated using twin design were 0.12, 0.72 and 0.32 for VO2max, Heart Rate max and endurance capacity respectively. Heritabilities of 0.28 and 0.06 for speed and placing respectively are reported in endurance horses. The aim of this study was to calculate the heritability of recovery heart rate, cardiac recovery time and average speed in long distance endurance racing.

Methods

The results of 132 endurance races (80–160 km) from 2007 to 2011 were analyzed. The database included 4421 horses of known pedigrees representing 655 sires with a mean of 18.5 products per sire. The data were analyzed using Restricted Estimator of Maximal Likelihood (REML, VCE6) method with animal mixed model including country, ride distance, age, gender, common environment as fixed effects and animal genetic as random effect.

Results

Heritabilities (SE) were 0.12 (0.06), 0.15 (0.02) and 0.46 (0.08) for speed, recovery heart rate and cardiac recovery time respectively.

Conclusions

The speed and heart rate recovery seem more influenced by training and environmental effects than the cardiac recovery time which is more influenced by genetics. This high heritability is consistent with heritability of V200 found in French Trotter population previously and may indicate a putative quantitative trait linkage.

Ethical Animal Research

Explicit owner informed consent for participation in this study is not stated. Sources of funding: National Studs (IFCE) and the Arabian Horse Association (ACA). Competing interests: none.
Acid‐Base Alterations in Barrel Racing Quarter Horses of Different Fitness Levels Assessed Via The Simplified Strong Ion Approach
Authors: Brito HCD , Charlie‐Silva I , Faria CCS , Queiroz‐Neto A , Ferraz GC
Published: June 2014

Introduction

The evaluation of acid‐base balance of horses is important because it detects alterations that affect their performance and health. There are studies relating these changes with endurance type effort, but few regarding sprint exercise. The purpose of this study was to determine whether the fitness level of Quarter Horses performing barrel racing could be differentiated by quantitative acid‐base analysis.

Methods

For this purpose, 10 horses were distributed into two groups: high (HF) and lower (LF) fitness as defined by the trainer. GPS and frequency meter were used for the measurements. Venous blood gas analysis was performed using a portable analyzer (I‐stat) before and after exercise. Strong ion difference (SID), anion gap (AG), strong ion gap (SIG) and concentration of non‐volatile buffers (Atot) were determined. Variables before and after exercise were compared within and between groups by t‐test (P<0.05).

Results

The average track distance was 125 m. There were no differences between maximum or average velocity and heart rate, which were 30.76 ± 0.53 km/h, 22.85 ± 0.28 km/h, 206 bpm ± 3.91 versus 27.7 ± 2.4 km/h, 21.94 ± 0.3 km/h and 203 bpm ± 5.77 for the HF and LF groups, respectively. SID values before exercise were significantly lower for the LF group. Both groups showed a significant increase in Atot and AG, while pH, HCO3‐, SIG and SID decreased significantly after exercise.

Conclusions

Metabolic acidosis was observed using both the traditional and the quantitative approach. It was not possible to differentiate the fitness level of horses in the study.

Ethical Animal Research

All procedures were approved by the institutional animal care and use committee of the university (CEUA, Process: 008481/11). Explicit owner informed consent for participation in this study is not stated. Sources of funding: UNESP Reitoria (PIBIC). Competing interests: none.
Acid‐Base Imbalances in Endurance Racing Using Traditional and Quantitative Approaches
Authors: Ferraz GC , Teixeira‐Neto AR , Silva IC , Nardi KB , Queiroz‐Neto A
Published: June 2014

Introduction

Acid‐base disturbances are frequently assessed using traditional variables PCO2, pH, and bicarbonate. This study aimed to compare the changes in acid‐base balance in horses performing a CEI endurance race (160 km) using traditional and quantitative methodologies.

Methods

Blood samples were drawn before racing, at the vet‐gate (66 km), immediately after racing, and 2 and 15 h after racing from 18 participating horses. The mean velocity of the horses was 17 km/h. PCO2 and pH were measured (I‐Stat). Strong ion difference (SID), anion gap (AG), strong ion gap (SIG) and total volatile buffers (Atot) were calculated using formulas from the literature. Data for finishers (F) and non‐finishers (N) was compared with an unpaired test. Data collected for finishers at all time‐points was compared by repeated ANOVA followed by Tukey's test.

Results

PCO2 was lower in group N at the 66 km time‐point. In group F, AG had a bimodal behaviour, declining immediately after exercise and then increasing at 2 and 15 hours. There was a slight increase in pH post‐exercise. After 2 hours, Atot increased while PCO2 decreased. Compared to SIG immediately after racing, SIG at 2 and 15 hours after racing was decreased. Traditional methodology suggested mild respiratory and metabolic alkalosis, possibly due to hyperventilation of the finishers. Quantitative methodology suggested metabolic acidosis reflected by decreasing SID trend and a significant increase of Atot.

Conclusions

Acid‐base imbalances are present in endurance racing horses and differences were found between the traditional and quantitative methods of assessment.

Ethical Animal Research

All procedures were approved by the institutional animal care and use committee of the university (CEUA, Process: 007347/13). Explicit owner informed consent for participation in this study is not stated. Sources of funding: FAPESP ‐ Fundação de Amparo à Pesquisa do Estado de São Paulo (Process 2013/00449‐8). Competing interests: none.
Serum Immunoglobulin Concentrations in Racing Endurance Horses
Authors: McKenzie E , Esser M , Payton E
Published: June 2014

Introduction

Serum immunoglobulin fractions were evaluated in horses participating in multi‐day endurance exercise.

Methods

Serum IgGa, IgGb, IgG(T), IgA, and IgM were measured using horse‐specific ELISA kits in 44 trained horses prior to racing, after each day of racing 50 miles per day and in 15 untrained matched control horses. Data were analyzed via repeated measures ANOVA (P<0.05).

Results

44, 18 and 9 horses completed one, two and three days of racing, respectively. Serum IgA before racing (1.97 ± 0.14 mg/dL) was similar to controls (1.48 ± 0.19) and after one, two or three days of racing (1.98 ± 0.13, 1.80 ± 0.15 and 1.76 ± 0.26). Serum IgM before racing (1.02 ± 0.05 mg/dL) was similar to controls (1.08 ± 0.12) and after one, two or three days of racing (1.03 ± 0.06, 0.91 ± 0.08 and 0.89 ± 0.11). Serum IgG(T) before racing (6.10 ± 0.41 mg/dL) was similar to controls (6.29 ± 0.58) and after racing one, two or three days (6.23 ± 0.45, 6.62 ± 0.63, and 6.65 ± 1.34). Serum IgGa was 2.41 ± 0.10 mg/dL before racing, and was similar to controls (2.45 ± 0.22) and each day of racing (2.58 ± 0.14, 2.39 ± 0.20, and 2.61 ± 0.22, on days one, two and three of racing). Resting serum IgGb concentration was significantly lower in control (5.71 ± 0.54 mg/dL) than trained horses (7.65 ± 0.41).

Conclusions

Serum IgGb is higher in trained endurance horses, perhaps reflecting immune stimulation related to disease exposure or more frequent vaccination.

Ethical Animal Research

All procedures were approved by the Oregon State University Institutional Animal Care and Use Committee. Owner informed consent was obtained for all horses in the study. Sources of funding: Department of Biomedical Sciences at Oregon State University. Competing interests: none.
Effect of A 90‐km Endurance Race on Resistance to Oxidation and Inflammation Levels in 6‐Year Old Horses
Authors: Robert C , Barrey E , Patrice T
Published: June 2014

Introduction

The aim of this study was to determine whether serum anti‐oxidant defenses are impaired by endurance exercise and to investigate possible correlation with performance in the race.

Methods

Blood samples were obtained from 23 Arabian or half‐Arabian horses (6 years old) the day before (T0) and 30 minutes after (T1) a 90‐km race. Performance records available included speed, heart rate 10 and 30 minutes after arrival and the rating by veterinarians based on recovery and gait (5 categories from ‘eliminated’ to ‘excellent’). Absorbance at 413 nm (A413), at 650 nm (A650) and absorbance of Rose Bengal (RB) were measured in sera at T0 and T1 (a higher absorbance means a lower antioxidant capacity). Relationships between blood variables and between T0 values and race results were evaluated using correlation analysis and means comparisons.

Results

All horses finished the race with an average speed of 16.3 km/h. Three horses were eliminated for lameness, one was excellent and the others were distributed between the other three categories. After the race, a significant increase of RB, A413, A413‐A650, PT and CK (P<0.001) was observed. At T0, RB and CK were significantly correlated (r = 0.52, P<0.01). At T1, absorbance values were significantly correlated with muscle enzymes and haptoglobin (r = 0.50–0.67, P<0.05). The speed of the horse was negatively correlated with RB at T0 (r = −0.42, P<0.05). No significant difference in absorbance values could be detected between the recovery categories.

Conclusions

A higher resistance to oxidative stress was observed before the race in the best performing horses.

Ethical Animal Research

The study design was approved by the Ethics Committee for the Alfort Veterinary School and the University of Paris‐Est under number 12/07/11‐1; owner informed consent was obtained before any manipulation on horses. Sources of funding: National Studs (IFCE), the Eperon Funds and the Arabian Horse Association (ACA). Competing interests: none.
A Standardised Gaited Field Test Produces Changes in Blood Biomarkers and Heart Rate in Four‐Beat Gaited Horses
Authors: Silva F , Melo S , Abreu J , Manso H , Manso Filho H
Published: June 2014

Introduction

There is little information about biochemical and physiologic responses to exercise in Brazilian gaited horses. The aim of this study was to evaluate blood biomarkers and heart rate (HR) in gaited horses during a standardized gaited field test (SGT).

Methods

Sixteen horses performed a SGT (10 min warm‐up, 30 min of marcha gait and 15 min recovery). Blood samples and HR were collected at rest, after warm‐up, after 15 (F + 15) and 30 min (F + 30) of marcha, and after recovery. Assays were performed to measure glucose, lactate, total plasma protein, hematocrit, urea, creatinine, glutamine, glutamate, triglycerides, total cholesterol, Ca, P, Mg, Na, Cl and K. HR was measured using a HR monitor. Results were analyzed using one‐way or two‐way ANOVA. Post‐hoc analyses included the Holm‐Sidak test, Student's t‐tests, and Pearson's correlation analyses. The null hypothesis was rejected when P<0.05.

Results

[Glucose] and [lactate] increased during SGT (P<0.05). A significant interaction between phase of SGT and fitness level was observed for [glucose] but not for [lactate]. The SGT also produced increases (P<0.05) in hematocrit, [TPP], [urea], [creatinine], [triglycerides], [P] and [K] and a reduction (P<0.05) in [Ca]. HR increased from ∼47 bpm at rest, to ∼140 bpm at F + 15 and F + 30 (P<0.05).

Conclusions

This study documents submaximal aerobic exercise, as performed during the GST is sufficient to alter energy biomarkers in gaited horses.

Ethical Animal Research

The study was approved by UFRPE's animal research committee (#62/2007‐CTA/DZ/UFRPE). Sources of funding: CAPES, IRCA Animal Nutrition and Cascatinha, Recanto da Serra, Annette and Abreu horse farms. Competing interests: none.
Accuracy of a Point‐of‐Care Lactate Analyzer for Measuring Blood and Plasma L‐Lactate Concentrations in Exercising Standardbreds
Authors: Constable P , Sulimai N , Tinkler S , Ko J , Couetil L
Published: June 2014

Introduction

The Accutrend® Lactate (formerly Accusport®) is a low cost point‐of‐care L‐lactate analyser. The analyser is widely used in the training of horses and has been used for research studies and to assist the clinical management of critically ill horses. The analyser is reported to be linear from 0.8–22.0 mmol/L (blood) and 0.7–26.0 mmol/L (plasma); however, test performance at high L‐lactate concentrations in equine blood and plasma has not been well documented. The purpose of this study was to determine the accuracy of the Accutrend® Lactate analyzer over a wide range of L‐lactate concentrations in paired blood and plasma samples.

Methods

Duplicate jugular blood samples were collected from 8 trained Standardbreds before, during, and after a simulated race on a treadmill into 4 mL partially evacuated tubes containing lithium heparin. Blood and plasma L‐lactate concentrations were measured using a colorimetric lactate‐oxidase mediated reaction (BM‐Lactate® test strips and Accutrend® Lactate) and the reference enzymatic method (L‐lactic dehydrogenase spectrophotometry at 340 nm using samples deproteinized with 8% perchloric acid). Data was analysed using Deming regression and Bland‐Altman plots adjusted for repeated measures (P<0.05).

Results

The reference method measured a wide range of L‐lactate concentrations in 128 blood (0.2–23.8 mmol/L) and 127 plasma (0.3–41.1 mmol/L) samples. The Accutrend® Lactate analyzer provided an accurate method of L‐lactate measurement, but only when blood and plasma L‐lactate concentrations were <12.5 mmol/L (79% of samples) and <15.0 mmol/L (64% of samples), respectively.

Conclusions

Blood L‐lactate concentrations >12.5 mmol/L and plasma L‐lactate concentrations >15.0 mmol/L measured by the Accutrend® Lactate analyzer underestimate the true value by a variable amount when compared with the enzymatic reference method.

Ethical Animal Research

The study was approved by the Institutional Animal Care and Use Committee at Purdue University. Sources of funding: Supported, in part, by a grant from the Indiana Horse Racing Commission. Competing interests: none.
Efficacy of Intravenous Dexamethasone Versus Placebo in Experimental Foot Lameness in Horses
Authors: Foreman C , Foreman J , Bergstrom B
Published: June 2014

Introduction

There are no refereed blinded controlled documentations of the skeletal analgesic efficacy of intravenous dexamethasone. The objective was to test the hypothesis that intravenous dexamethasone is more efficacious in alleviating lameness than placebo in a reversible adjustable heart bar shoe model of equine foot pain.

Methods

Eight healthy horses (7 Thoroughbreds, 1 Warmblood, aged 6.5 ± 3.3 years, age range 2–11 years) underwent weekly intravenous treatments 1 hour after lameness induction. Treatments were isotonic saline placebo at 1 ml/45 kg bwt, or dexamethasone (2 mg/ml in polyethylene glycol) at 0.045 mg/kg bwt, a typical dose used twice daily in the USA for anti‐inflammatory effect. Treatments were randomly assigned and administered by a co‐investigator who had no input on Heart Rate (HR) and Lameness Score (LS) measurements. Another investigator unaware of treatment assignments monitored HR and LS every 20 min for 5 hours after lameness induction and then hourly through 12 hours post‐treatment. One week later treatment assignments were reversed and the experiment was repeated. Repeated measures ANOVA and post hoc Tukey's test were used to identify significant effects at P<0.05.

Results

After treatment, mean HR and LS were not different between treatments (P>0.05). HR and LS remained elevated over pre‐lameness values throughout the 13‐hour post‐lameness monitoring period (P<0.05).

Conclusions

It was concluded that intravenous dexamethasone was no more effective than saline placebo. Neither treatment was effective at alleviating lameness over a 12‐hour post‐treatment period in this model. Dexamethasone at 0.045 mg/kg bwt should not affect acute foot lameness during equine exercise or performance.

Ethical Animal Research

The study was approved by the University of Illinois Institutional Animal Care and Use Committee. Sources of funding: Fédération Equestre Internationale. Competing interests: none.
Chuckwagon Field Study: High‐Sensitivity Cardiac Troponin‐T Increases with Exercise But Is Not Correlated with the Presence of Arrhythmias During Exercise
Authors: Massie S , Leguillette R
Published: June 2014

Introduction

In chuckwagon racing, dubbed the “half‐mile of hell”, teams often race multiple consecutive days. Horses are in peak condition, however rare cases of sudden death attributed to cardiovascular failure occur. There are concerns regarding cumulative racing and its impact on the risk of sudden death. The objective was to determine if cumulative exercise affects integrity of the myocardium, assessed by high‐sensitivity troponin‐T (cTnT), and if the presence of arrhythmias during race or recovery affects plasma cTnT concentrations.

Methods

Heart rate and electrical activity were recorded on 148 horses (9 ± 2.7 years) during racing days 1 and 2. 750 plasma samples were analysed (374 pre‐exercise, 376 post‐exercise) comparing cTnT before and after activity (paired t‐test). Associations between consecutive racing days, age and cTnT were analysed (ANOVA, Pearson Correlation). The relationship between arrhythmias and cTnT was also examined.

Results

cTnT increased significantly with exercise (pre: 4.52 ng/L ± 0.17, post: 5.20 ng/L ± 0.23, P<0.001). However cTnt was not affected by cumulative exercise. A correlation between age and cTnT was found. 4235 arrhythmic events were recorded. No association existed between cTnT (post‐exercise) and the presence of arrhythmias during exercise and recovery.

Conclusions

This is the first study examining the effect of exercise on high‐sensitivity cTnT in horses and first large‐scale study on chuckwagon horses. Racing increases cTnT, however values remain low, suggesting myocardial damage of little clinical significance. Chuckwagon horses have long careers therefore age and cTnT could be further examined. cTnT was not affected by the presence of arrhythmias during exercise, indicating chuckwagon racing is well tolerated.

Ethical Animal Research

The study was approved by the Veterinary Sciences Animal Care Committee of the University of Calgary (AC120049) and onwer informed consent was obtained. Sources of funding: Clinical Research Fund from the University of Calgary's Faculty of Veterinary Medicine. Summer Studentships were funded by NSERC. Competing interests: none.