A Delphi Study to Determine International and National Equestrian Expert Opinions on Domains and Sub-Domains Essential to Managing Sporthorse Health and Welfare in the Olympic Disciplines.

The public is increasingly questioning equestrianism's social license to operate. While the focus historically centered on horseracing, increased scrutiny is now being placed on how dressage, showjumping, and eventing are addressing equine management and welfare concerns. Nominated equestrian federation and equestrian organization experts (n = 104) directly involved in international and/or national-level horse sports took part in a four-stage, iterative Delphi to obtain consensus on what factors should be considered essential to manage sporthorse health and welfare. Five core domains were agreed as essential: training management, competition management, young horse management, health status and veterinary management, and the horse-human relationship. Two further domains: stable and environmental management, and welfare assessment were rated as important but not essential, as most respondents felt that these areas were already managed well. Participants felt increased education and guidance combined with further policy development and regulation are needed to support stakeholders to optimize sporthorse management. An appetite to engage with research to generate evidence that promotes sporthorse welfare was evident. The development of a sporthorse welfare charter and evidence-based guidelines to inform the management and monitoring of sporthorses' health and welfare are recommended to provide horses with a good life and to safeguard the future of equestrian sports.

The effect of acute equine temporomandibular joint inflammation on response to rein-tension and kinematics.

Background: Although the temporomandibular joint (TMJ) is the major contact point between the reins in the riders' hand, the bit in the mouth, and the rest of the horse under saddle, the role of inflammation of this joint on equine locomotion and rein tension is unknown. Objective: To determine the effect of acute TMJ inflammation on rein-tension and horse movement when horses were long-reined on a treadmill. Study design: A randomized, controlled, cross-over design. Methods: Five horses were trained by one clinician to walk and trot on a treadmill wearing long-reining equipment instrumented with a rein-tension device and reflective optical tracking markers. Subjective assessment of horse's dominant side, and movement, were determined without rein-tension (free walk and trot); and with rein-tension (long-reined walk and trot). Continuous rein-force data from both sides were collected over ~60s from each trial. Movement was recorded using a 12-camera optical motion capture system. One randomly assigned TMJ was subsequently injected with lipopolysaccharide and the treadmill tests repeated by investigators blinded to treatment side. A second, identical assessment was performed 10 days later with the opposite TMJ being the target of intervention. Results: All horses showed reduced rein-tension on the injected (inflamed) side. Increased rein-tension was required on the non-injected side at trot, to maintain them in the correct position on the treadmill post-injection. The only kinematic variable to show any significant change due to rein tension or TMJ inflammation during the walk or trot was an increase in forward head tilt in the presence of rein tension in the trot after injection. Main limitations: Low number of horses and investigation of response to acute inflammation only. Conclusion: TMJ inflammation changed, subjectively and objectively, the response to rein-input, but the horses did not become lame.

Determining Objective Parameters to Assess Gait Quality in Franches-Montagnes Horses for Ground Coverage and Over-Tracking - Part 1: At Walk.

Ground coverage and over-tracking are two gait quality traits describing the forward movement of the front respectively the hind limbs in relation to stride length and over-tracking distance. To investigate the complex interplay of different movement patterns in ground coverage and over-tracking, limb and body kinematics of 24 Franches-Montagnes (FM) stallions were measured with 3D optical motion capture (OMC) on a treadmill during an incremental speed test at the walk (1.4-2.0 m/s). The significance and amount of explained variance of kinematic parameters on stride length and over-tracking distance were estimated using linear mixed-effect models, with speed and horse as random effects. Two separate models were tested: a full model with all parameters measurable by OMC, and a reduced model with a subset of parameters also measurable with inertial measurement units (IMUs). The kinematic parameters were correlated to the subjective scores from six breeding experts to interpret their external validity. The parameter for ground coverage at the walk, explaining most of the variance in stride length, were the maximal forelimb retraction angle (11%) measured with OMC, and the range of pelvis pitch (10%) if measuring with IMUs. The latter was also the most relevant for quantifying over-tracking, explaining 24% to 33% of the variance in the over-tracking distance. The scores from most breeding experts were significantly correlated (r ≥ |0.41|) with the fore- and hind limb protraction angles, which reflect the textual definition of ground coverage and over-tracking. Both gait quality traits can be objectively quantified using either OMC or IMUs.

Gait quality scoring data of Franches-Montagnes stallions at walk and trot on a treadmill by experts of the breed and their reliability.

This article presents the data obtained from the scoring of 24 stallions of the Franches-Montagnes (FM) horse breed by six experts of this breed. The experts scored six traits at walk and eight at trot from the video recordings of these stallions walking and trotting on a treadmill during an incremental speed test. The scores were given on a scale of one to nine. All experts scored the same videos twice (two scoring tests) with a time interval of two years, and without feedback from the first scoring. Video sequences were presented in a different order between first and second scoring. The inter- and intra-rater reliability of the data was assessed using intraclass correlation coefficients (ICC) to evaluate its quality.

"Feel the Force"-Prevalence of Subjectively Assessed Saddle Fit Problems in Swiss Riding Horses and Their Association With Saddle Pressure Measurements and Back Pain.

Ill-fitting saddles can impair the well-being and performance of horses. Saddle fit is generally assessed subjectively by a trained professional or with an electronic saddle pressure mat, but little is known about the agreement between both methods. The study aims were (1) to assess the prevalence of saddle fit issues in a riding sound Swiss horse population, (2) to investigate how well the subjective assessment correlates with objectively measured pressure magnitude and distribution under the saddle during riding, and (3) how well both correlate with back pain of the horse. Only 10% of the saddles were free of the assessed problems. Pressures exceeded clinically relevant thresholds in 15% of the horses. There was no clear correlation between back pain and pressure magnitude, but back pain was associated with certain subjectively assessed fit problems. Statistically significant associations between fit problems and the expected pressure patterns were found for panel angles, curvature of the saddle, width of the panel channel, and the waist of the saddle. There was no or limited association of pressure patterns with the balance of the saddle, width and angle of the tree head, or the symmetry of the panels. The results revealed that certain fit problems were reflected in the electronically measured pressure distribution and that the subjective assessment can therefore provide relevant information. Pressure magnitude showed only limited association with back pain, which indicates that there are other factors involved in the development of back problems in horses.

Asymmetries of horses walking and trotting on treadmill with and without rider.

BACKGROUND: Left-right movement symmetry is a highly desirable characteristic in sport horses. OBJECTIVES: This study compared movement symmetry in well-trained dressage horses in unridden and unrestrained position and ridden in a dressage frame, and investigated possible associations between gaits. STUDY DESIGN: Experimental study. METHODS: Seven sound, high-level dressage horses were measured at walk and sitting trot on a treadmill at several speeds under two conditions: with and without rider. Left-right differences in stance duration, stance protraction and retraction based on longitudinal hoof positions, ipsilateral limb tracking, minimum and maximum vertical positions of the dorsal spinous processes of the sixth thoracic (T6), third sacral vertebrae (S3) and wing of atlas, and vertical ground reaction forces were calculated and analysed in mixed models. RESULTS: At walk, five body variables indicated increased asymmetry in the ridden condition compared with unridden condition: forelimb stance duration (unridden/ridden left-right differences 9 vs 13 ms; P = .008), forelimb stance protraction (P = .004), stance retraction (P = .001) and first force peak (P = .003), and hindlimb stance retraction (P = .01). At trot, six body variables were more asymmetrical in the ridden condition: forelimb stance duration (2.5 vs 3.8 ms, P = .004); hindlimb stance protraction (P < .0001) and retraction (P = .01), T6 minimum (4 vs 6 mm, P = .001), T6 maximum (9 vs 11 mm, P = .01) and S3 maximum (6 vs 12 mm, P < .001). Five variables had significant associations between asymmetries at walk and trot, but only three demonstrated a positive slope. MAIN LIMITATIONS: A limited number of horses and riders were studied. Measurements were performed on a treadmill. CONCLUSIONS: High-level horses moved slightly more asymmetrically when ridden in a dressage frame than in the unridden condition.

Adaptation strategies of horses with induced forelimb lameness walking on a treadmill.

BACKGROUND: There is a paucity of research describing the gait pattern of lame horses at the walk. OBJECTIVES: To describe the changes in motion pattern and vertical ground reaction forces (GRFz) in horses with induced forelimb lameness at the walk and compare those changes with the changes observed at the trot. STUDY DESIGN: Experimental study. METHODS: In 10 clinically sound Warmblood horses, moderate forelimb lameness was induced using a sole pressure model followed by trot and walk on a treadmill. Kinematic data were collected using 3D optical motion capture (OMC), and GRFz by an instrumented treadmill. Mixed models were used to compare sound baseline versus forelimb lameness (significance was set at P < .05). RESULTS: Lameness induction significantly reduced peak GRFz on the second force peak, and vertical impulse in the lame limb. Stride and stance duration in all limbs were reduced. Lameness significantly affected the vertical movement symmetry of the head and withers. Maximum limb retraction angle, fetlock extension and protraction speed were reduced in the lame limb. Body centre of mass (COM) translation was reduced in the side-to-side direction and increased in the vertical and fore-aft directions. Several compensatory kinetic and kinematic changes were observed in the nonlame limbs. The observed changes in both kinetics and kinematics were generally smaller at walk with fewer variables being affected, compared to the trot. MAIN LIMITATIONS: Only one degree and type of orthopaedic pain (sole pressure) was studied. CONCLUSIONS: Compensatory strategies of forelimb lameness at the walk include alteration of several kinetic and kinematic parameters and have some specific patterns and inter-individual differences that are not seen at the trot. However, much like at the trot, head movement and forelimb vertical force symmetry seem to be the most useful parameters to detect forelimb lameness at walk.

Riding Soundness-Comparison of Subjective With Objective Lameness Assessments of Owner-Sound Horses at Trot on a Treadmill.

Lameness is a symptom indicative of pain or injury of the locomotor apparatus. Lame horses generally should not be ridden. However, owners' ability to assess lameness has been questioned. This study's aim was to use subjective lameness assessments and objective gait analysis to generate a descriptive overview of movement and weight-bearing asymmetries of owner-sound riding horses. 235 horses were subjectively assessed in a field study, and the owner's perception of their horse's orthopedic health was recorded through an online survey. 69 horses were re-evaluated by gait analysis at an equine hospital. During trot on an instrumented treadmill, the gait was scored by a veterinarian using lameness grades from 0/5 (sound) to 3/5 (moderate lameness visible at trot). Movement asymmetry of the head (HDmin) and pelvis (PDmin) and weight-bearing asymmetry were quantified simultaneously. The prevalence of subjectively scored lameness grade ≥2/5 in one or more limbs was 55% during study part 1 and 74% during study part 2. Movement asymmetry of the head and/or pelvis exceeding HDmin ≥12 mm and/or PDmin ≥6 mm was found in 57% of the horses. 58% showed weight-bearing asymmetries between contralateral front and/or hind limbs of ≥3% body mass. Gait analysis showed considerable variability of movement and weight-bearing asymmetry values, sometimes independent of the clinical lameness grade, especially in the forehand. Several horses with lameness grade ≤1/5 had asymmetry values greater than mentioned thresholds. The analysis of movement and weight-bearing asymmetry revealed that these objective variables did not necessarily act uniformly and therefore should be interpreted with caution.

Husbandry, Use, and Orthopedic Health of Horses Owned by Competitive and Leisure Riders in Switzerland.

The use of horses in competitive sports receives increasing criticism from the public, mainly due to the potential for injury. However, it is unclear if orthopedic and other health issues are more common in competition horses than those in leisure horses. The aim of this study was to assess husbandry, use, and orthopedic health in Swiss riding horses and to compare these aspects between horses owned by self-identified competitive riders (CR) and leisure riders (LR) in Switzerland. A total of 237 owners completed an online survey providing information on their athletic ambitions, their horse's husbandry, health, training, and tack. Two experienced veterinarians assessed gait irregularities, muscular development, and back pain in the horses and evaluated saddle fit. Compared with horses owned by competitive riders (CH), a higher proportion of horses kept by leisure riders (LH) were kept unshod, under more natural conditions, and turned out with other horses. LH were exercised less frequently, and LR trained less frequently with instructors. CR reported less time since the last saddle check and the use of more training aids during riding. No differences between the two groups could be found in orthopedic health, muscular development, or back pain, but LH had higher body condition scores and a slightly higher proportion of saddles with at least one fit problem. Our data revealed no increased prevalence of the assessed health problems in competition horses compared with leisure horses in Switzerland. However, suboptimal saddle fit and muscular development, back pain, and gait irregularity are frequent in both groups and deserve more attention.

Influence of Functional Rider and Horse Asymmetries on Saddle Force Distribution During Stance and in Sitting Trot.

Asymmetric forces exerted on the horse's back during riding are assumed to have a negative effect on rider-horse interaction, athletic performance, and health of the horse. Visualized on a saddle pressure mat, they are initially blamed on a nonfitting saddle. The contribution of horse and rider to an asymmetric loading pattern, however, is not well understood. The aim of this study was to investigate the effects of horse and rider asymmetries during stance and in sitting trot on the force distribution on the horse's back using a saddle pressure mat and motion capture analysis simultaneously. Data of 80 horse-rider pairs (HRP) were collected and analyzed using linear (mixed) models to determine the influence of rider and horse variables on asymmetric force distribution. Results showed high variation between HRP. Both rider and horse variables revealed significant relationships to asymmetric saddle force distribution (P < .001). During sitting trot, the collapse of the rider in one hip increased the force on the contralateral side, and the tilt of the rider's upper body to one side led to more force on the same side of the pressure mat. Analyzing different subsets of data revealed that rider posture as well as horse movements and conformation can cause an asymmetric force distribution. Because neither horse nor rider movement can be assessed independently during riding, the interpretation of an asymmetric force distribution on the saddle pressure mat remains challenging, and all contributing factors (horse, rider, saddle) need to be considered.

Biomechanical findings in horses showing asymmetrical vertical excursions of the withers at walk.

The walk and trot are inherently symmetrical gaits, making them potentially suitable for the detection of left-right asymmetries. The aims of this study were to describe asymmetrical vertical excursions of the withers at walk in non-lame high-level dressage horses and to seek associations between these asymmetric movements and other kinematic variables and vertical ground reaction forces (vGRFs). Seven dressage horses, judged clinically as being sound, walked unridden and unrestrained on a treadmill with an integrated force measuring system (480 Hz), from which spatiotemporal and vGRF variables were extracted. Markers were tracked by 12 infrared cameras (240 Hz). The vertical position of the sixth thoracic vertebra (T6), limb protraction and retraction distances throughout stance, and global limb lengths were determined. Contralateral trial-mean differences were calculated, including difference in T6 minimum vertical position between contralateral steps (T6minDiff). Mixed models were used to study associations between symmetry parameters. Trial-mean T6minDiff ranged between 0.3-23 mm. Of the seven horses, five consistently dropped the withers more in early left forelimb stance, one was fairly symmetrical, and one dropped the withers more in early right forelimb stance. Comparisons between contralateral limbs showed the following associations. The forelimb that was retracted when T6min was lowest showed greater retraction at toe-off (1 mm increase predicted 0.17 mm T6minDiff increase) and shorter stance duration (1 ms decrease predicted 0.3 mm T6minDiff increase). The hind limb that was in midstance when T6min was lowest showed a greater range of motion during the stance phase (1 mm increase in protraction or retraction predicted 0.2 mm T6minDiff increase). The haunches were displaced away from the side of the forelimb that was protracted when T6min was lowest (1 mm lateral shift predicted 0.07 mm T6minDiff increase). Forelimb and hind limb vGRF parameters were non-significant. Asymmetry of vertical withers movement in horses assessed as being sound at trot was related to a complex pattern of asymmetries in spatiotemporal variables throughout the stride cycle rather than to vertical load redistribution between the forelimbs. This suggests that the asymmetry may be due to inherent laterality rather than weight-bearing lameness.

Passive Dynamics Explain Quadrupedal Walking, Trotting, and Tölting.

This paper presents a simplistic passive dynamic model that is able to create realistic quadrupedal walking, tölting, and trotting motions. The model is inspired by the bipedal spring loaded inverted pendulum (SLIP) model and consists of a distributed mass on four massless legs. Each of the legs is either in ground contact, retracted for swing, or is ready for touch down with a predefined angle of attack. Different gaits, that is, periodic motions differing in interlimb coordination patterns, are generated by choosing different initial model states. Contact patterns and ground reaction forces (GRFs) evolve solely from these initial conditions. By identifying appropriate system parameters in an optimization framework, the model is able to closely match experimentally recorded vertical GRFs of walking and trotting of Warmblood horses, and of tölting of Icelandic horses. In a detailed study, we investigated the sensitivity of the obtained solutions with respect to all states and parameters and quantified the improvement in fitting GRF by including an additional head and neck segment. Our work suggests that quadrupedal gaits are merely different dynamic modes of the same structural system and that we can interpret different gaits as different nonlinear elastic oscillations that propel an animal forward.

Comparison of limb loading and movement of Icelandic horses while tölting and trotting at equal speeds.

OBJECTIVE: To compare gait mechanics and limb loading in Icelandic horses tölting and trotting at equal speeds and estimate their impact on orthopedic health. ANIMALS: 12 orthopedically normal Icelandic horses. PROCEDURES Kinetic and kinematic gait variables were simultaneously recorded as each horse was ridden at a tölt and trot on an instrumented treadmill at 3.4 m/s and 3.9 m/s. Differences between gaits were tested via 1-factor repeated-measures ANOVA. RESULTS: Horses had a higher stride rate and lower stride impulses at a tölt than at a trot. For forelimbs at a tölt, shorter relative stance duration resulted in higher peak vertical force (Fz(peak)). Conversely, for hind limbs, longer relative stance duration resulted in lower Fz(peak). The higher head-neck position at a tölt versus trot caused no weight shift to the hind limbs, but a higher forehoof flight arc and lower proretraction movement were identified. Stance durations for forelimbs were briefer than for hind limbs at a tölt, and the inverse was observed at a trot. Minimal height of the horse's trunk at the point of Fz(peak) of the respective limb suggested a spring-like mechanism for all limbs at a tölt. Hind limb measurements revealed no evidence of increased collection. Stride-to-stride limb timing varied more at a tölt than at a trot. At a trot, horses had brief or no suspension phases and a slightly 4-beated footfall rhythm was common. Post hoc energetic estimations revealed that tölting at the measured speeds was less advantageous than trotting. CONCLUSIONS AND CLINICAL RELEVANCE: High forelimb action in Icelandic horses and higher head-neck position at a tölt were associated with more restricted limb proretraction, higher Fz(peak), and faster force onset than at a trot. The impact of these differences on orthopedic health needs to be investigated more in detail.

Effects of shoeing on intra- and inter-limb coordination and movement consistency in Icelandic horses at walk, tölt and trot.

To enhance expressiveness of forelimb movement and improve the four-beat rhythm of the tölt, Icelandic horses are commonly ridden with excessively high and long hooves. The aim of this study was to objectively assess the effect of shoeing on intra- and inter-limb coordination and limb movement consistency (inter-stride variability) at walk, tölt and trot. Thirteen sound and fit Icelandic horses accustomed to exercise with a rider on a treadmill were assessed with long and high hooves commonly used for competition (S(H)) and with the hooves trimmed according to the standards of normal shoeing (S(N)). Limb timing variables were extracted from the four vertical ground reaction force curves measured with an instrumented treadmill. Measurements were taken at walk and at two tölting and trotting speeds. High hooves with long toes reduced stride rate and increased breakover duration. At the tölt, the footfall rhythm showed less tendency to lateral couplets. Movement consistency of the walk remained unchanged, whereas, at the tölt, stride-to-stride variability of selected time parameters increased in SH and/or at the higher velocity. At the faster trotting speed, variability of hind limb duty factor decreased, whereas variability of contralateral step duration in the forelimb increased. High hooves with long toes improve the clearness of the four-beat footfall rhythm of the tölt, but disturb the movement consistency of the gait. The prolonged breakover duration observed in all gaits may have negative implications for the health of the palmar structures of the distal foot.

Effects of shoeing on limb movement and ground reaction forces in Icelandic horses at walk, tölt and trot.

Tölt is a symmetric four-beat gait with a speed range extending into that of trot and canter. Specific shoeing methods, such as unnaturally high and long hooves, are used to enforce individual gait predisposition. The aim of this study was to assess the consequences of this shoeing style on loading and movement of the limbs at walk, tölt and trot, and at different velocities. Simultaneous kinetic and kinematic gait analysis was carried out at walk (1.4m/s) and at two tölting and trotting speeds (3.3m/s and 3.9 m/s) on an instrumented treadmill. Thirteen sound Icelandic horses were first measured with high, long front hooves (SH) and, 1 week later, after trimming the hooves according to standard shoeing principles (SN). Comparing SH with SN, front hooves had 21 ± 5 mm longer dorsal hoof walls, and the shoeing material per hoof was 273 ± 50 g heavier. In all three gaits, gait quality, as it is currently judged, was improved with SH due to a lower stride rate, a longer stride length and a higher, but not wider, forelimb protraction arc, which were also positively associated with speed. Forelimb-hind limb balance remained unchanged, but limb impulses were higher. Apart from an increase of ≤ 2.2% in the forelimbs at the faster speed of both tölt and trot, SH had little influence on vertical peak forces.

Saddle pressure distributions of three saddles used for Icelandic horses and their effects on ground reaction forces, limb movements and rider positions at walk and tölt.

Icelandic horse riding practices aim to place the rider further caudally on the horse's back than in English riding, claiming that a weight shift toward the hindquarters improves the quality of the tölt (e.g. giving the shoulder more freedom to move). This study compared saddle pressure patterns and the effects on limb kinetics and kinematics of three saddles: an Icelandic saddle (S(Icel), lowest point of seat in the hind part of the saddle), a treeless saddle cushion (S(Cush)) and a dressage-style saddle (S(Dres)). Twelve Icelandic horses were ridden with S(Icel), S(Cush) and S(Dres) on an instrumented treadmill at walk and tölt. Saddle pressure, limb forces and kinematics were recorded simultaneously. With S(Cush), pressure was highest under the front part of the saddle, whereas the saddles with trees had more pressure under the hind area. The saddles had no influence on the motion patterns of the limbs. The slight weight shift to the rear with S(Cush) and S(Icel) may be explained by the more caudal position of the rider relative to the horse's back.

Applied load on the horse's back under racing conditions.

With the intention of limiting the weight on horses' backs and guaranteeing maximal freedom of movement, commonly used racing saddles are small and have minimal cushioning. Poor saddle cushioning may limit performance or even affect soundness of the back. The aim of this study was to measure the pressure under an average racing saddle ridden by a jockey at racing speed. Saddle pressure using a medium-sized racing saddle (length 37 cm, weight 450 g) was measured in five actively racing Thoroughbred horses. All horses were trained at the same facility and ridden by their usual professional jockey, weighing 60 kg. The horses were ridden on a race track at canter (mean velocity, V1 ± standard deviation, SD: 7.7 ± 0.4m/s) and gallop (V2 ± SD: 14.0 ± 0.7 m/s). Maximal pressure was 134 kPa at V1 and 116 kPa at V2. Mean peak pressure was 73.6 kPa at V1 and 54.8 kPa at V2. The maximal total force did not differ between the two velocities and was approximately twice the jockey's bodyweight. The centre of pressure lateral range of motion differed significantly, with excursions of 23 mm at V1 and 37 mm at V2; longitudinal excursion was 13 mm for V1 and 14 mm for V2. The highest pressure (>35 kPa) was always localised along the spinous processes over an average length of 12.5 cm. It was concluded that racing saddles exert high peak pressures over bony prominences known to be sensitive to pressure.

Atrial natriuretic peptide and cardiac troponin I concentrations in healthy Warmblood horses and in Warmblood horses with mitral regurgitation at rest and after exercise.

OBJECTIVE: Atrial natriuretic peptide (ANP) and cardiac troponin I (cTnI) serve as biomarkers for increased cardiac pressure/volume loading and for myocardial stress or damage. The objective was to describe the time course of plasma ANP concentrations (CpANP) and plasma cTnI concentrations (CpcTnI) in horses with mitral regurgitation (MR) compared to healthy horses at rest and after exercise, and to describe the relationship of CpANP with cardiac dimensions and intracardiac pressures. ANIMALS: 15 healthy Warmblood horses and 7 Warmblood horses with MR. METHODS: Cardiac dimensions at rest were measured using echocardiography. All horses underwent standardized treadmill exercise. Biomarker concentrations and intracardiac pressures were measured at rest and after exercise. Hypotheses were tested using statistical methods. The level of significance was P < 0.05. RESULTS: Horses with MR showed increased left atrial (LA) and left ventricular (LV) dimensions but similar exercise capacity compared to healthy horses. Pulmonary capillary wedge pressures (PCWP) and CpANP increased with exercise. Horses with MR had higher PCWP and higher CpANP at rest and after exercise compared to healthy horses, with the maximum difference in CpANP reached 10 min after exercise. CpANP was significantly related to PCWP and - although inconsistently and only in healthy horses - to echocardiographic indices of LA and LV size and function. CpcTnI was low throughout the study in both groups. CONCLUSIONS: CpANP is increased in horses with MR and is related to LA pressures and to left heart dimensions. MR is not necessarily associated with exercise intolerance and exercise-induced myocardial stress or damage.

High-speed cinematographic evaluation of claw-ground contact pattern of lactating cows.

To evaluate the manner in which a cow's claws make contact with the ground at the walk, the gait, and in particular the claw-ground contact pattern, were studied in 12 healthy, lactating dairy cows, using high-speed cinematography (500frames/s) while the animals were walking on a treadmill. The results showed that the limbs were advanced around the contralateral limbs in a sigmoid curve. The feet contacted the ground with the foot axis and the tips of the claws rotated slightly outwards. In all cows the lateral claws contacted the ground before the medial claws in the hindlimbs, and in 10/12 cows in the forelimbs. The heel of the lateral claws was the region of initial contact with the ground in the hindlimbs of all cows and in the forelimbs in 9/12 cows. Lateral 'heel first' contact in the fore and hindlimbs appeared to be the normal gait pattern in these animals. Compared with a previous study of heifers, lactating cows had a larger step width in the hindlimbs and a smaller step width in the forelimbs. These ground contact patterns offer an explanation for the predisposition to claw disorders of the lateral claw of the hindlimb. The results of this study reinforce the suggestion that soft floor surfaces should be provided for cattle to prevent mechanical injury to the claws.

Short term analgesic effect of extracorporeal shock wave therapy in horses with proximal palmar metacarpal/plantar metatarsal pain.

Extracorporeal shock wave therapy (ESWT) is an accepted form of treatment for chronic cases of proximal suspensory desmitis (PSD). Subjective evaluation of horses shortly after being treated with ESWT has led clinicians to comment on an immediate reduction in lameness. This study aimed to evaluate the analgesic effect of ESWT on 16 horses with PSD or PSD-like pain in a fore- or hindlimb. To objectively assess lameness, gait analysis was performed on an instrumented treadmill before and 6, 24, 48 and 72h after ESWT of the origin of the suspensory ligament and the results compared to the effects of local anaesthesia. Stride frequency, stance duration, vertical impulse and peak vertical force were determined. Thermographic imaging and evaluation of skin sensitivity of the treated area were carried out before and after ESWT in the same interval as gait analysis. The results showed that there were no significant improvements in the investigated parameters at any time after ESWT; however, in horses with affected forelimbs the contralateral weightbearing asymmetry decreased significantly 72h after ESWT. Neither skin sensitivity nor thermographic imaging revealed changes that could be attributed to ESWT.