Effect of superficial harrowing on surface properties of sand with rubber and waxed-sand with fibre riding arena surfaces: a preliminary study

A recent epidemiological study identified various aspects of arena surfaces and arena surface maintenance that were related to risk of injury in horses and that arena maintenance is important in reducing injury risk. However, there has been little research into how properties of arena surfaces change with harrowing. This study aimed to compare the properties of different arena surface types pre- and post-harrowing. The Orono Biomechanical Surface Tester fitted with accelerometers and a single- and a three-axis load cell was used to test 11 arenas with two different surfaces types, sand with rubber (SR) and waxed-sand with fibre (WSF). Three drop tests were carried out at 10 standardised locations on each arena. Mixed models were created to assess the effect of surface type, pre- or post-harrowing, and drop number on the properties of the surface, including maximum horizontal deceleration, maximum vertical deceleration, maximum vertical load and maximum horizontal load.Post-harrowing, none of the parameters were altered significantly on SR. On WSF, maximum vertical deceleration and maximum vertical load significantly decreased post-harrowing. The differences in the effects of superficial harrowing on SR and WSF could be attributed to the different compositions and sizes of the surface material. The results suggest that different maintenance techniques may be more suitable for different surface types and that the effects of superficial harrowing are short-lived due to the rapid re-compaction of the surface with repeated drops on WSF. Further work is required to determine the effects of other maintenance techniques, and on other surface types.     

Preliminary Examination of Farriery and Hoof Care Practices and Owner-Reported Injuries in Sport Horses in New Zealand

Retrospective management and owner-reported injury data, and measurement of forelimb hoof conformation, were collected via a cross-sectional survey from a convenience sample of 96 registered show jumping (n = 67) and dressage (n = 29) horses. Most of the horses were medium- to upper-level performers, aged 9 (interquartile range [IQR] 7–12) years, and in the current rider's ownership for 28 (IQR 12–60) months. The horses were trained 45 (IQR 35–60) minutes, 6 days per week, on a sand or sand mix arena. Failure to train for ≥7 days was reported in 26 of 96 horses, generally associated with lameness diagnosed by a veterinarian (16/29), with a median time-off of 26 (IQR 14–93) days. During the preceding 12 months, 33% of the riders had been working with the farrier on hoof-related issues, 30% of which had involved ≤2 issues. This remedial work often involved a veterinarian (14/30) or allied health practitioner (6/30). Most horses were hot shod (67/89) with conventional fullered shoes. Uneven feet were identified in 16 of 89 horses but were not positively associated with inability to train, possibly reflecting the minor variation between feet. Uneven feet were associated with variation in heel length and angle measurements and a greater sole length and reduced sole width, rather than smaller and boxy. Multiple correspondence plots identified an association of uneven feet with the dressage horses rather than show jumping horses.     

The effect of collection and extension on tarsal flexion and fetlock extension at trot

A recent epidemiological study indicated that various factors may be related to injury in dressage horses, but the mechanism by which these injuries occur has yet to be determined. The suspensory ligament (SL) is a frequent site of injury, and it is assumed that greatest strain is placed on this structure in collected trot; this has yet to be proved conclusively. The study aimed to investigate the effect of collected and extended trot on the hindlimb movement pattern. Four dressage horses were fitted with markers and inertial motion sensors (IMS). High‐speed video was obtained for 2 strides on each rein in collected and extended trot on 3 different surfaces: waxed outdoor; sand/plastic granules; and waxed indoor. Maximal tarsal flexion during stance and distal metatarsal coronary band ratio (MTCR), representing fetlock extension, were determined. Inertial motion sensor data determined stride duration, speed and stride length. Data were compared between collection and extension within horses on each surface, and compared between surfaces. Collected trot had significantly lower speed and stride length but longer stride duration than extended trot on all surfaces. All horses had less tarsal flexion and fetlock extension in collected compared with extended trot (P<0.05), which is likely to increase SL loading. The study findings indicate that extended trot may increase SL strain, providing a possible explanation for the high incidence of SL injury in horses trained for extravagant movement. It is possible that substantial use of extended trot could be a risk factor for development of suspensory desmitis, which might be one contributory factor in the prevalence of suspensory desmitis in young horses repeatedly undertaking extravagant movement.     

The Use of a Technical Device for Testing the Sport-Functional Properties of Riding Surfaces

The riding surface is an important and modifiable factor in the development injuries in sport horses. An objective and simple examination of the sport-functional properties of riding surfaces, such as shock absorption, is thus desirable. The aim of the present study was to evaluate the use of a handy device to test the sport-functional properties of riding surfaces. Therefore, a technical device, called Artificial Athlete, was used on five riding surfaces: two sand–synthetic indoor arenas, one sand–sawdust indoor arena, and two outdoor arenas, one with a sand footing layer and one with a grass surface. The shock absorption, the energy restitution, and the vertical deformation measurements were acquired by the Artificial Athlete. Additionally, the hoof acceleration of six warmblood horses trotting by hand on the five investigated riding surfaces was recorded. The parameters of the Artificial Athlete and the acceleration data during hoof landing were compared. The outcome of the statistical analysis illustrated that the shock absorbing parameter was not in agreement with the results of the acceleration data, whereas the results of the vertical deformation parameter were mostly in accordance with the results of the hoof-acceleration measurement. In conclusion, the use of the Artificial Athlete for testing the sport-functional properties of riding surfaces was assessed as unsuitable because of the large deviations between the results of the shock absorption measured by the Artificial Athlete and the hoof-acceleration data. However, it could be shown that the vertical deformation parameter could be helpful in the assessment of the sport-functional quality of riding surfaces.     

Eprinomectin treatment of psoroptic mange in hunter/jumper and dressage horses: a prospective, randomized, double-blinded, placebo-controlled clinical trial

The purpose of this prospective, double-blinded, placebo-controlled clinical trial was to investigate the efficacy of topical eprinomectin for the treatment of psoroptic mange infestation in horses. 24 privately owned hunter/jumper and dressage horses were diagnosed with psoroptic mange infestation based on physical findings and skin scraping results were enrolled and randomly assigned to either topical eprinomectin pour-on solution (at a dose of 500mug/kg body weight weekly once for four applications) treatment group or a placebo group (purified water). Clinical evaluations and skin scrapings were done by the same veterinary investigator at the beginning, during and at the end of the treatment. Both owners and veterinary investigator were blinded to the allocation to the groups. The efficacy of eprinomectin was assessed both clinically and parasitologically by the presence or absence of viable mites. Horses were scraped for psoroptic mites on days 7, 14, 21, 28 and 40 for follow-up. Fisher's exact test was used to assess differences between the eprinomectin treatment and placebo in the number of horses without mites (cure rates) on each assessment date. It was found that significantly fewer eprinomectin treated horses had P. equi mites detected on skin scrapings (p<0.01) than the placebo group. In conclusion, eprinomectin was effective and safe therapy against natural infestations of P. equi in the horses included in this study.     

Effect of Crumb Rubber Made From Recycled Tires on Air Quality in an Indoor Riding Arena: A Pilot Study

Our hypothesis was that recycled crumb rubber can significantly decrease air particulate matter when applied on the top of existing arena sand, and the objective of our study was to test this hypothesis. Treatments were as follows: A (control—existing sand floor), B (recycled rubber 1.5″), and C (recycled rubber 3″). Air quality was measured using three DC1100 monitors (Dylos Corporation; Riverside, CA). Data collections occurred during advanced riding classes twice per week for 3 weeks using randomly assigned horses and riders. Data were analyzed as a three-way analysis of variance with fixed effects using a Tukey post hoc test with SAS (version 9.4; SAS Institute Inc) and significance established at P < .05. Application of the recycled rubber material significantly reduced air particulate matter in both treatments B and C for particles measured at 0.5 μm and 2.5 μm. We observed no significance associated with monitor or time. We observed no difference between treatments B and C. Recycled rubber material significantly reduced particulate matter in the air during an indoor riding class when applied over existing arena sand flooring.     

Effect of Competition on Nitric Oxide, Carbon Monoxide, and Cyclic Guanosine Monophosphate Levels in Training Horses

The aim of this study was to compare the effect of exercise on nitric oxide (NO), carbon monoxide (CO), and cyclic guanosyl monophosphate (cGMP) levels in jumping and dressage horses involved in competition. Blood samples were collected from the jugular vein of 100 horses involved in jumping or dressage competition at three time points: baseline at rest, on reaching the schooling but before exercise, and over a jump or dressage course. Fourteen healthy horses not involved in competition were used as control group. Exercise increased plasma CO concentration in both jumping and dressage horses, and this effect was more apparent in dressage horses. Exercise also increased NO plasma concentration in jumping horses, whereas it did not significantly modify NO plasma concentration in dressage horses. After exercise, plasma cGMP concentration was higher in both groups. Our results show that different signaling pathways are initially activated by exercise and that this activation is specific to the different modes of exercise. This information can be used to optimize warm-up and cool-down procedures for sport horses or to optimize training programs for equine athletes.     

Prevalence of Helicobacter equorum in faecal samples from horses and humans

Recently, a new enterohepatic Helicobacter species, H. equorum, was isolated from faecal samples of two clinically healthy horses. At the onset of this study, nothing was known about the prevalence of this organism in horses, nor was there any information available on the possible zoonotic character of this agent. This study aimed to determine the prevalence of H. equorum in faecal samples from equine and human origin. Therefore, faecal samples of 120 healthy privately owned horses, 227 healthy riding-school horses and 239 hospitalised horses were screened for H. equorum-DNA by means of a PCR amplifying a 1074-bp fragment of the 23S rRNA gene with primers specific for H. equorum. The vast majority of the hospitalised horses were under treatment with an antimicrobial agent at the moment of sampling, while the other horses had not been treated with an antimicrobial agent in the 14 days preceding the sampling. Stool samples of 531 humans suffering from gastro-intestinal disease and 100 clinically healthy humans were likewise examined. H. equorum-DNA was demonstrated in faeces from 0.8% of the privately owned horses, 3.1% of the riding-school horses and 7.9% of the hospitalised horses. The prevalence of H. equorum was significantly higher in hospitalised than in healthy, privately owned horses (P=0.02). H. equorum-DNA was not detected in human samples. These results indicate that the prevalence of H. equorum in horses may be influenced by the health status of the investigated horse population and/or by antimicrobial treatment. We may additionally assume that this micro-organism does not commonly infect humans.     

Canter lead change kinematics of superior olympic dressage horses

Limb contact variables of the gaits of superior dressage horses were determined for competitors at the 1988 Seoul Summer Olympic Games in the finals of the Individual Dressage competition. Two 16-mm motion picture cameras were aimed perpendicular to the plane of motion along the HXF and KXM diagonals of the standard dressage arena, and filmed at 100 fps. Nineteen of the horses selected as finalists for individual dressage medals were filmed during the Grand Prix Special test executing one-stride canter lead changes, two-stride canter lead changes and the left lead extended canter. Velocities, stride lengths and stride durations were 7.03±.07 m/s, 4.15±.05 m and .592±.004 s for the extended canter. Across all stride frequencies, score was optimized with extended canter strides of the greatest length, with no upper limit detected to optimal stride length. Canter strides with lead changes had lower velocities, shorter strides and longer durations than strides without a lead change, with velocities, stride lengths and stride durations, respectively, of 3.36±.05 m/s, 2.08±.04 m and .617±.003 s for one-stride canter lead change strides; 3.65±.07 m/s, 2.21±.04 m and .605±.003 s for pre-change canter two-stride lead change strides; and 3.95±.07 m/s, 2.44±.04 m and .621±.004 s for post-change canter two-stride lead change strides. This study provided the first objective documentation of the canter limb contact patterns of world-class dressage horses.     

Force and pressure distribution beneath a conventional dressage saddle and a treeless dressage saddle with panels

The objective of this study was to compare forces and pressure profiles beneath a conventional dressage saddle with a beechwood spring tree and a treeless dressage saddle without a rigid internal support and incorporating large panels and a gullet. The null hypothesis was that there is no difference in the force and pressure variables for the two saddles. Six horses were ridden by the same rider using the conventional dressage saddle and the treeless dressage saddle in random order and pressure data were recorded using an electronic pressure mat as the horses trotted in a straight line. The data strings were divided into strides with ten strides analyzed per horse–saddle combination. Variables describing the loaded area, total force, force distribution and pressure distribution were calculated and compared between saddles using a three-factor ANOVA (P < 0.05).Contact area and force variables did not differ between saddles but maximal pressure, mean pressure and area with pressure >11 kPa were higher for the treeless dressage saddle. The panels of the treeless dressage saddle provided contact area and force distribution comparable to a conventional treed saddle but high pressure areas were a consequence of a narrow gullet and highly-sloped panels. It was concluded that, even with a treeless saddle, the size, shape, angulation, and position of the panels must fit the individual horse.     

Genetic parameters of biokinematic variables at walk in the Spanish Purebred (Andalusian) horse using experimental treadmill records

The breeding scheme of Spanish Purebred (SPB) horses includes the selection of dressage performance as a main objective. Specific characteristics of the gaits are required for dressage aptitude and some could be selected for genetically. The gait of 130 SPB horses was recorded on a treadmill at walk (1.7 m/s). Nineteen biokinematic variables were analysed, 18 were directly measured from the video sequences and 1 estimated from the measurements. The data were used to estimate genetic parameters of gaits (heritability and genetic correlations). The aim was to select the biokinematic variables to include in the breeding scheme of this breed, based on their genetic parameters and their relation with dressage performance.The resulting heritabilities were medium-high (51.1% with heritability higher than 0.5). This implies a high response for selection which allows an indirect early selection for dressage performance. The genetic correlations are abundant and range between 0.28 and 0.99, which allows a reduction in the number of selected variables.Based on our results, a selection scheme should include: stride duration and length; fore and hindlimb duration and length; hindlimb maximum height of hoof; maximal retraction–protraction range of forelimb; hindlimb stance phase duration and fore and hindlimb swing phase duration.     

Genetic correlations between dressage,show jumping and studbook‐entry inspection traits in a process of specialization in Dutch Warmblood horses

Sport performance in dressage and show jumping are two important traits in the breeding goals of many studbooks. To determine the optimum selection scheme for jumping and dressage, knowledge is needed on the genetic correlation between both disciplines and between traits measured early in life and performance in competition in each discipline. This study aimed to estimate genetic parameters to support decision‐making on specialization of breeding horses for dressage and show jumping in Dutch warmblood horses. Genetic correlations between performance of horses in dressage and show jumping were estimated as well as the genetic correlation between traits recorded during studbook‐entry inspections and performance in dressage and show jumping competitions. The information on competition comprised the performance of 82 694 horses in dressage and 62 072 horses in show jumping, recorded in the period 1993–2012. For 26 056 horses, information was available for both disciplines. The information on traits recorded at studbook‐entry inspections comprised 62 628 horses, recorded in the period 1992–2013. Genetic parameters were estimated from the whole dataset and from a subset without horses recorded in both disciplines. Additionally, the genetic parameters were estimated in three different time periods defined by horses' birth year. The genetic correlation between dressage and show jumping in the whole dataset was ?0.23, and it was ?0.03 when it was estimated from horses recorded in only one discipline. The genetic correlation between dressage and show jumping was more negative in the most recent time period in all the cases. The more negative correlation between disciplines in more recent time periods was not reflected in changes in the correlations between competitions traits and the traits recorded in the studbook‐first inspection. These results suggest that a breeding programme under specialization might be most effective defining two separate aggregate breeding goals for each of the disciplines.     

Assessment of Resting Insulin and Leptin Concentrations and Their Association With Managerial and Innate Factors in Horses

The purpose of this study was to determine how insulin and leptin concentrations varied in a large population of privately owned horses. Further, the study was designed to examine the relationships between insulin and leptin with innate (sex, age, breed) and managerial (diet, exercise) factors in these horses. Resting blood samples (for determination of glucose, insulin, and leptin concentrations), body condition scores, feed information, and health history were collected from 366 privately owned horses. In this group of horses, 48% were considered overweight (Body Condition Score ≥6) and 8% were considered hyperinsulinemic (insulin concentrations >30 μU/mL). Confirming the findings of studies within research herds, both insulin and leptin concentrations were found to be correlated with body condition score (P < .001). It was also found that geldings had higher insulin concentrations than mares (P < .05). Ponies were found to have higher insulin and leptin concentrations as well as higher body condition scores, than several other breeds examined. While not a specific measure of insulin sensitivity, resting insulin concentrations have been associated with quantitative measurements of insulin sensitivity and may be useful in large-scale studies for estimating insulin and glucose dynamics. Because of the association between insulin resistance and obesity with diseases such as laminitis, the findings of the present study may help owners identify horses that may be at risk for the development of such conditions.     

The effect of occlusal equilibration on sport horse performance

The objective of this study was to investigate the effect of routine dental occlusal equilibration treatment on dressage horse performance. Sixteen horses (11 treated; 5 untreated) ridden by a single rider performed a standardized dressage test twice and were scored by two experienced dressage judges according to recognized movements and rider cues. All horses were sedated and a full-mouth speculum was used to facilitate a complete oral examination. Treated horses had dental equilibration performed using a motorized dental instrument. The horses performed a second test 48-hours after dental equilibration, exactly as the baseline test, with the judges and rider blinded as to treatment group. The total test score as well as the individual movement scores were evaluated for equality of variance and statistical tests were applied to determine the influence of treatment. There was no significant improvement in the test score of horses that had received occlusal equilibration.     

Genetic relations of movement and free-jumping traits with dressage and show-jumping performance in competition of Dutch Warmblood horses

Genetic parameters for traits evaluated at the studbook entry inspection and genetic correlations with dressage and show-jumping performance in competition were estimated. Data comprised 36,649 Warmblood horses that entered the studbook between 1992 and 2002. The genetic analyses were performed using univariate and bivariate animal models. Heritabilities of the studbook entry traits were estimated in the range 0.15–0.40. The movement traits showed moderate to strong mutual genetic correlations, whereas the genetic correlations of movement traits with free-jumping traits were weak to moderate. The free-jumping traits showed strong to very strong mutual genetic correlations.

Competition results of 33,459 horses with performance in dressage and 30,474 horse with performance in show-jumping were linked to the studbook entry data to estimate the genetic relationship with performance in competition. Heritability estimates for dressage and show jumping were 0.14. Genetic correlations of the movement traits with dressage were moderate to strong, and with show-jumping weak to moderate. Genetic correlations of the free-jumping traits with dressage were weak to moderate and unfavourable. The free-jumping traits were genetically strong to very strong correlated to show-jumping. It was concluded that a selection of the traits evaluated at the studbook entry inspection will favourably contribute to estimation of breeding values for sport performance.     

Variation in conformation of Swedish warmblood horses and conformational characteristics of élite sport horses

The variation in conformation of 356 Swedish Warmblood horses is described, using a quantitative method of measuring horses. Thirty-three of the horses were élite dressage horses, 28 were élite showjumpers, 100 were riding school horses and 195 were unselected four-year-olds. Most horses had a long body form. The average height at the withers was 163.4 cm. Sixty per cent of the horses had a bench knee conformation, 50 per cent had a toe-in conformation of the forelimbs and 80 per cent had outwardly rotated hind limbs. The majority of these deviations were mild or moderate. Conformation was influenced by sex and age. Mares were smaller and had longer bodies and shorter limbs. The élite dressage horses and showjumpers had larger hock angles and more sloping scapulas than other horses. The showjumpers also had smaller fetlock angles in the front limbs. It is suggested that the larger hock angles among the elite horses may be because hocks with small angles are more prone to injury, and because small hock angles may negatively influence the ability to attain the degree of collection necessary for good performance in advanced classes.     

Immunization with Trichophyton verrucosum Vaccine in Hunter/Jumper and Dressage Horses with Naturally Occurring Trichophyton equinum Infection: A Prospective,Randomized, Double-Blinded,Placebo-Controlled Clinical Trial

The aim of the current study was to investigate the efficacy of Trichophyton verrucosum vaccine in hunter/jumper and dressage horses with trichophytosis caused by Trichophyton equinum (cross immunity). A total of 25 hunter/jumper and dressage horses between the ages of 2 and 14 years, naturally infected with Trichophyton equinum, were enrolled and randomly assigned to either a placebo or an intramuscular lyophilized Trichophyton verrucosum vaccine group. Clinical evaluations were done by the same investigator, who scored clinical healing at the beginning, during, and at the end of the treatment and was blinded to allocation to the groups. At the end of the trial, vaccine treatment significantly decreased the investigator's clinical scores (P < .001), and no significant changes were detected in the placebo treatment group. In all of the horses vaccinated, the lesions improved gradually within 7 to 12 days after vaccination. Complete clinical remission was detected within 28 to 42 days, and all treated horses became culture negative within 25 days of starting treatment. No clinical healing was observed in nine untreated control horses throughout the study. No recurrence was observed in treated horses within 10 months after therapy. Results of the current study indicate that inactivated Trichophyton verrucosum vaccine may be a safe and effective therapy for horses with Trichophyton equinum infection.     

Use of field records and competition results in genetic evaluation of station performance tested Swedish Warmblood stallions

The main objective of this study was to investigate possibilities to increase accuracy in the selection and test of Swedish warmblood stallions by combining information from stallion performance tests (SPT) with information from competitions and riding horse quality tests (RHQT). Data on 801 stallions judged at the SPT 1979–2005 were used for the analyses, which also included about 14 900 horses from the RHQT, 26 800 horses with results in show jumping and 14 200 horses with results in dressage competitions.Heritability coefficients were on average 0.41 for individual gaits under rider and 0.36–0.65 for jumping traits in SPT. Heritabilities for competition traits were 0.17 for dressage and 0.27 for show jumping. The heritability for overall conformation in SPT was 0.25. Genetic correlations between stallion performance test traits and competition results were 0.44–0.77 for gaits and dressage, and 0.78–0.96 for jumping traits in SPT and show jumping. The genetic correlation between conformation and results in dressage competitions was 0.22.For stallions participating in SPT in 2004 and 2005 accuracy increased when evaluating stallions by adding information from relatives that have taken part in RHQT and competitions. For show jumping accuracy changed from 0.60 to 0.68 for stallions born in Sweden, an increase with 13%, when information from RHQT and competitions in show jumping were used. For stallions born in a foreign country, the corresponding figure was, 5%, lower. For dressage the information from RHQT and competition results in dressage changed the accuracy from 0.41 to 0.55, an increase with 34%, for stallions born in Sweden. The improvement in accuracy for imported stallions was 11%.     

Management of Primary Injuries of the Medial Collateral Ligament of the Carpus in Two Horses

This case report describes the successful management of two horses with medial carpal collateral ligament injury. This is a rare cause of forelimb lameness and existing reports indicate a poor prognosis for return to athletic function with conservative management. Both horses were treated with a combination of box rest with controlled exercise and high-intensity laser therapy (HILT). Both horses returned to previous athletic function, one at Grand Prix level dressage and one at Novice level eventing. With appropriate management, the prognosis for carpal collateral ligament injury may be good. From this report, it is unclear whether a rehabilitation program including HILT offers improved prognosis compared with a rehabilitation program alone.     

Polysaccharide storage myopathy in the M. longissimus lumborum of showjumpers and dressage horses with back pain

This study was designed to investigate whether horses with clinical signs of back pain due to suspected soft tissue injuries were affected by polysaccharide storage myopathy (PSSM). Diagnosis of PSSM in muscle biopsies obtained from the M. longissimus lumborum of 5 showjumpers and 4 dressage horses with a history of back pain is reported. M. longissimus lumborum biopsies of these horses were characterised histopathologically and in 3/9 cases also by electron microscopy. Observations were compared with M. gluteus biopsies of the same horses, and with M. gluteus biopsies obtained from 6 Standardbreds with recurrent exertional rhabdomyolysis and from 6 healthy trotters. M. longissimus biopsies from horses with back pain showed pathognomonic signs of PSSM, i.e. high glycogen and/or abnormal complex amylase-resistant polysaccharide deposits. Similar features were found in M. gluteus biopsies of the same horses. Sections of horses with rhabdomyolysis had increased PAS stain when compared with healthy horses, but did not show amylase-resistant material. Qualitative observations were corroborated by quantitative histochemistry (optical densities) of sections stained with PAS and amylase PAS. This study demonstrated the presence of PSSM in the M. longissimus of showjumpers and dressage horses with back pain and indicates that epaxial muscle biopsy is an option in diagnosing back problems in horses when clinical examination and imaging techniques do not provide a precise diagnosis.