Differences in equine spinal kinematics between straight line and circle in trot.

Work on curved tracks, e.g. on circles, is commonplace within all forms of horse training. Horse movements in circles are naturally asymmetric, including the load distribution between inner and outer limbs. Within equestrian dressage the horse is expected to bend the back laterally to follow the circle, but this has never been studied scientifically. In the current study 12 horses were measured (optical motion capture, 100 Hz) trotting on left and right circles and on the straight without rider (soft surface). Data from markers placed along the spine indicated increased lateral bending to the inside (e.g. left bending on the left circle) of the thoracolumbar back (difference left circle vs. straight - 3.75°; right circle + 3.61°) and the neck (left - 5.23°; right + 4.80° vs. straight). Lateral bending ROM increased on the circle (+ 0.87° and + 0.62°). Individual variation in straight-circle differences was evident, but each horse was generally consistent over multiple trials. Differences in back movements between circle and straight were generally small and may or may not be visible, but accompanying changes in muscle activity and limb movements may add to the visual impression.

Intersegmental strategies in frontal plane in moderately-skilled riders analyzed in ridden and un-mounted situations.

The symmetry of the rider is highly relevant, and in the equestrian community it is generally thought that a symmetrical rider has a better possibility to influence the horse in an optimal way. The aim of the study was to analyse and compare frontal plane kinematics of the core body segments in ten riders while riding and while rocking a balance chair from side-to-side. It was hypothesized that the riders were asymmetrical in relation to their intersegmental strategies when comparing between left and right directions and that individual riders would display the same postural strategies when riding and when rocking the balance chair. Ten moderately-skilled riders wore a full-body marker set that was tracked by a motion capture system as they rocked a balance chair from side to side. Inertial measurement units attached to the head, trunk and pelvis were used to measure the segmental movements while riding in left and right directions. Roll rotation data for head, trunk and pelvis were averaged over available strides/cycles. Results from mixed models showed that the riders were asymmetric when comparing riding in left vs right directions, for example the trunk was rotated 19° to the right on the right circle and 14° to the left on the left circle, on average. Riders adopted the same asymmetrical posture whether they were riding in the left or right direction on straight lines, circles or leg yielding. A significant relationship was found between postural asymmetries when riding and when rocking the balance chair, one degree of pelvis or head roll asymmetry on the chair predicted 2.4 (SE 0.9) degrees of asymmetry while riding. Future studies may investigate the value of seated, off-horse postural training for improving rider symmetry and thereby equestrian performance.

Lateral movement of the saddle relative to the equine spine in rising and sitting trot on a treadmill.

Saddle slip, defined as a progressive lateral displacement of the saddle during ridden exercise, has recently been given attention in the scientific press as a potential sign of lameness. The aim of this study was to objectively quantify the normal lateral movement (oscillations) of the saddle relative to the horse in non-lame horses, and associate this movement to the movements of the horse and rider. Data from seven Warmblood dressage horses competing at Grand Prix (n = 6) or FEI Intermediate (n = 1) level, ridden by their usual riders, were used. Simultaneous kinetic, kinematic and saddle pressure measurements were conducted during sitting and rising trot on a force-measuring treadmill. The maximum lateral movement of the caudal part of the saddle relative to the horse's spine (MAX) was determined for each diagonal step. A mixed model was applied, with MAX as outcome, and T6 and S3 vertical position, rigid body rotation angles (roll, pitch, yaw) of the horse's and rider's pelvis, vertical ground reaction forces, saddle force, and rider position (rising in rising trot, sitting in rising trot or sitting in sitting trot) as explanatory variables. The least square means for MAX were 14.3 (SE 4.7) mm and 23.9 (SE 4.7) mm for rising and sitting in rising trot, and 20.3 (SE 4.7) mm for sitting trot. A 10 mm increase in maximum pelvic height at push off increased MAX by 1.4 mm (p<0.0001). One degree increase in rider pelvis roll decreased MAX 1.1 mm, and one degree increase in rider pelvis yaw increased MAX 0.7 mm (both p<0.0001). The linear relationships found between MAX and movements of both horse and rider implies that both horse and rider movement asymmetries are reflected in the lateral movements or oscillations of the saddle in non-lame horses.

Vertical movement symmetry of the withers in horses with induced forelimb and hindlimb lameness at trot.

BACKGROUND: The main criteria for lameness assessment in horses are head movement for forelimb lameness and pelvic movement for hindlimb lameness. However, compensatory head nod in horses with primary hindlimb lameness is a well-known phenomenon. This compensatory head nod movement can be easily misinterpreted as a sign of primary ipsilateral forelimb lameness. Therefore, discriminating compensatory asymmetries from primary directly pain-related movement asymmetries is a prerequisite for successful lameness assessment. OBJECTIVES: To investigate the association between head, withers and pelvis movement asymmetry in horses with induced forelimb and hindlimb lameness. STUDY DESIGN: Experimental study. METHODS: In 10 clinically sound Warmblood riding horses, forelimb and hindlimb lameness were induced using a sole pressure model. The horses were then trotted on a treadmill. Three-dimensional optical motion capture was used to collect kinematic data from reflective markers attached to the poll, withers and tubera sacrale. The magnitude and side (left or right) of the following symmetry parameters, vertical difference in minimum position, maximum position and range-up were calculated for head, withers, and pelvis. Mixed models were used to analyse data from induced forelimb and hindlimb lameness. RESULTS: For each mm increase in pelvic asymmetry in response to hindlimb lameness induction, withers movement asymmetry increased by 0.35-0.55 mm, but towards the contralateral side. In induced forelimb lameness, for each mm increase in head movement asymmetry, withers movement asymmetry increased by 0.05-0.10 mm, in agreement with the head movement asymmetry direction, both indicating lameness in the induced forelimb. MAIN LIMITATIONS: Results must be confirmed in clinically lame horses trotting overground. CONCLUSIONS: The vertical asymmetry pattern of the withers discriminated a head nod associated with true forelimb lameness from the compensatory head movement asymmetry caused by primary hindlimb lameness. Measuring movement symmetry of the withers may, thus, aid in determining primary lameness location.

Comparing subjective and objective evaluation of show jumping competition and warm-up arena surfaces.

The development of safety and quality standards for equestrian surfaces needs to be based on objective, repeatable measurements which allow comparisons between surfaces. These measurements should incorporate the assessment of surface performance by riders. This study provides data from objective and subjective assessment of functional properties of high-level show jumping competition and warm-up arenas. Twenty-five arenas in nine international show jumping events were evaluated by mechanical in-situ testing with a surface tester, rider assessments using visual analogue scales (198 riders provided 749 arena evaluations), descriptions of arena constructions and by laboratory tests of surface material. Mixed models were used to present subjective evaluation of rider perception of the functional properties for each arena while controlling for rider and event. The association between objective and subjective assessments were also explored creating mixed models, controlling for rider and event. Mechanical measurements of impact firmness, and to a lesser extent cushioning and grip, had a significant positive association with the riders' perception. Responsiveness as assessed by the Orono biomechanical surface tester (OBST) was negatively associated with the riders' perceptions, which suggests riders and the OBST had different concepts of this functional property and that further developments of the OBST might be necessary. Objectively measured uniformity showed no useful association with riders' perception. Even though arena assessments were made by top level riders, a substantial inter-rider variation was demonstrated.

Environmental Risk Factors for Diabetes Mellitus in Cats.

BACKGROUND: Diabetes in cats resembles type 2 diabetes in people. The etiology is not fully understood, but both genetic and environmental factors are believed to contribute. OBJECTIVES: To assess the associations of environmental risk factors with diabetes in cats. ANIMALS: Cats with a diagnosis of diabetes (n = 396) insured by a Swedish insurance company during years 2009-2013, and a control group (n = 1,670) matched on birth year. METHODS: A web-based questionnaire was used in a case-control study. An invitation to participate was sent to owners of 1,369 diabetic cats and 5,363 control cats. The survey contained questions related to the cat's breed, age, sex, neutering status, body condition, housing, access to the outdoors, activity level, diet, eating behavior, feeding routine, general health, stressful events, other pets in the household, medications, and vaccination status. Data were analyzed by multiple logistic regression. RESULTS: Response rate was 35% for the diabetic group and 32% for the control group. Indoor confinement, being a greedy eater, and being overweight were associated with an increased risk of diabetes. In cats assessed by owners as being normal weight, there was an association between eating predominantly dry food and an increased risk of diabetes (Odds ratio 3.8; 95% confidence intervals 1.3-11.2). CONCLUSIONS AND CLINICAL IMPORTANCE: Dry food is commonly fed to cats worldwide. The association found between dry food and an increased risk of diabetes in cats assessed as normal weight by owners warrants further attention.

Lungeing on hard and soft surfaces: Movement symmetry of trotting horses considered sound by their owners.

REASONS FOR PERFORMING STUDY: Lungeing is often part of the clinical lameness examination. The difference in movement symmetry, which is a commonly employed lameness measure, has not been quantified between surfaces. OBJECTIVES: To compare head and pelvic movement symmetry between surfaces and reins during lungeing. STUDY DESIGN: Quantitative gait analysis in 23 horses considered sound by their owners. METHODS: Twenty-three horses were assessed in-hand and on the lunge on both reins on hard and soft surfaces with inertial sensors. Seven movement symmetry parameters were quantified and used to establish 2 groups, namely symmetrical (n = 9) and forelimb-lame horses (n = 14), based on values from straight-line assessment. Movement symmetry values for left rein measurements were side corrected to allow comparison of the amount of movement symmetry between reins. A mixed model (P<0.05) was used to study effects on movement symmetry of surface (hard/soft) and rein (inside/outside with respect to movement symmetry on the straight). RESULTS: In forelimb-lame horses, surface and rein were identified as significantly affecting all head movement symmetry measures (rein, all P<0.0001; surface, all P<0.042). In the symmetrical group, no significant influence of surface or rein was identified for head movement symmetry (rein, all P>0.245; surface, all P>0.073). No significant influence of surface or rein was identified for any of the pelvic movement symmetry measures in either group. CONCLUSIONS: While more symmetrical horses showed a consistent amount of movement symmetry across surfaces/reins, horses objectively quantified as lame on the straight showed decreased movement symmetry during lungeing, in particular with the lame limb on the inside of a hard circle. The variation within group questions straight-line movement symmetry as a sole measure of lameness without quantification of movement symmetry on the lunge, ideally on hard and soft surfaces to evaluate differences between reins and surfaces. In future, thresholds for lungeing need to be determined using simultaneous visual and objective assessment.

Rater agreement of visual lameness assessment in horses during lungeing.

REASONS FOR PERFORMING STUDY: Lungeing is an important part of lameness examinations as the circular path may accentuate low-grade lameness. Movement asymmetries related to the circular path, to compensatory movements and to pain make the lameness evaluation complex. Scientific studies have shown high inter-rater variation when assessing lameness during straight line movement. OBJECTIVES: The aim was to estimate inter- and intra-rater agreement of equine veterinarians evaluating lameness from videos of sound and lame horses during lungeing and to investigate the influence of veterinarians' experience and the objective degree of movement asymmetry on rater agreement. STUDY DESIGN: Cross-sectional observational study. METHODS: Video recordings and quantitative gait analysis with inertial sensors were performed in 23 riding horses of various breeds. The horses were examined at trot on a straight line and during lungeing on soft or hard surfaces in both directions. One video sequence was recorded per condition and the horses were classified as forelimb lame, hindlimb lame or sound from objective straight line symmetry measurements. Equine veterinarians (n = 86), including 43 with >5 years of orthopaedic experience, participated in a web-based survey and were asked to identify the lamest limb on 60 videos, including 10 repeats. The agreements between (inter-rater) and within (intra-rater) veterinarians were analysed with κ statistics (Fleiss, Cohen). RESULTS: Inter-rater agreement κ was 0.31 (0.38/0.25 for experienced/less experienced) and higher for forelimb (0.33) than for hindlimb lameness (0.11) or soundness (0.08) evaluation. Median intra-rater agreement κ was 0.57. CONCLUSIONS: Inter-rater agreement was poor for less experienced raters, and for all raters when evaluating hindlimb lameness. Since identification of the lame limb/limbs is a prerequisite for successful diagnosis, treatment and recovery, the high inter-rater variation when evaluating lameness on the lunge is likely to influence the accuracy and repeatability of lameness examinations and, indirectly, the efficacy of treatment.

Head and pelvic movement asymmetry during lungeing in horses with symmetrical movement on the straight.

REASONS FOR PERFORMING STUDY: Lungeing is commonly used as part of standard lameness examinations in horses. Knowledge of how lungeing influences motion symmetry in sound horses is needed. OBJECTIVES: The aim of this study was to objectively evaluate the symmetry of vertical head and pelvic motion during lungeing in a large number of horses with symmetric motion during straight line evaluation. STUDY DESIGN: Cross-sectional prospective study. METHODS: A pool of 201 riding horses, all functioning well and considered sound by their owners, were evaluated in trot on a straight line and during lungeing to the left and right. From this pool, horses with symmetric vertical head and pelvic movement during the straight line trot (n = 94) were retained for analysis. Vertical head and pelvic movements were measured with body mounted uniaxial accelerometers. Differences between vertical maximum and minimum head (HDmax, HDmin) and pelvic (PDmax, PDmin) heights between left and right forelimb and hindlimb stances were compared between straight line trot and lungeing in either direction. RESULTS: Vertical head and pelvic movements during lungeing were more asymmetric than during trot on a straight line. Common asymmetric patterns seen in the head were more upward movement during push-off of the outside forelimb and less downward movement during impact of the inside limb. Common asymmetric patterns seen in the pelvis were less upward movement during push-off of the outside hindlimb and less downward movement of the pelvis during impact of the inside hindlimb. Asymmetric patterns in one lunge direction were frequently not the same as in the opposite direction. CONCLUSIONS: Lungeing induces systematic asymmetries in vertical head and pelvic motion patterns in horses that may not be the same in both directions. These asymmetries may mask or mimic fore- or hindlimb lameness.

Incidence of Diabetes Mellitus in Insured Swedish Cats in Relation to Age, Breed and Sex.

BACKGROUND: Diabetes mellitus (DM) is a common endocrinopathy in cats. Most affected cats suffer from a type of diabetes similar to type 2 diabetes in humans. An increasing prevalence has been described in cats, as in humans, related to obesity and other lifestyle factors. OBJECTIVES: To describe the incidence of DM in insured Swedish cats and the association of DM with demographic risk factors, such as age, breed and sex. ANIMALS: A cohort of 504,688 individual cats accounting for 1,229,699 cat-years at risk (CYAR) insured by a Swedish insurance company from 2009 to 2013. METHODS: We used reimbursed insurance claims for the diagnosis of DM. Overall incidence rates and incidence rates stratified on year, age, breed, and sex were estimated. RESULTS: The overall incidence rate of DM in the cohort was 11.6 cases (95% confidence interval [CI], 11.0-12.2) per 10,000 CYAR. Male cats had twice as high incidence rate (15.4; 95% CI, 14.4-16.4) as females (7.6; 95% CI, 6.9-8.3). Domestic cats were at higher risk compared to purebred cats. A significant association with breed was seen, with the Burmese, Russian Blue, Norwegian Forest cat, and Abyssinian breeds at a higher risk compared to other cats. No sex predisposition was found among Burmese cats. Several breeds with a lower risk of DM were identified. CONCLUSIONS AND CLINICAL IMPORTANCE: Our results verify that the Burmese breed is at increased risk of developing DM. We also identified several previously unreported breeds with increased or decreased risk of DM.

Incidence of and mortality from kidney disease in over 600,000 insured Swedish dogs.

Kidney disease is an important cause of morbidity and mortality in dogs. Knowledge about the epidemiology of kidney disease in the dog population is valuable and large-scale epidemiological studies are needed. The aim of the present study was to use insurance data to estimate kidney-related morbidity and mortality in the Swedish dog population. Insurance company data from insured dogs during the years 1995-2006 were studied retrospectively. Incidence and mortality were calculated for the whole group of dogs as well as divided by sex and breed. The total number of veterinary care insured dogs was 665,245. The total incidence of kidney disease in this group of dogs was 15.8 (15.3-16.2) cases/10,000 dog-years at risk. The number of dogs in the life insurance was 548,346 and in this group the total kidney-related mortality was 9.7 (9.3-10.2) deaths/10,000 dog-years at risk. The three breeds with the highest incidence of kidney disease were the Bernese mountain dog, miniature schnauzer and boxer. The three breeds with the highest mortality caused by kidney disease were the Bernese mountain dog, Shetland sheepdog and flat-coated retriever. In conclusion, the epidemiological information provided in this study concerning kidney disease in dogs can provide valuable information for future research.

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.

A cohort study of epilepsy among 665,000 insured dogs: incidence, mortality and survival after diagnosis.

The main objective of this study was to estimate the incidence and mortality rates of epilepsy in a large population of insured dogs and to evaluate the importance of a variety of risk factors. Survival time after a diagnosis of epilepsy was also investigated. The Swedish animal insurance database used in this study has previously been helpful in canine epidemiological investigations. More than 2,000,000 dog-years at-risk (DYAR) were available in the insurance database. In total, 5013 dogs had at least one veterinary care claim for epilepsy, and 2327 dogs were euthanased or died because of epilepsy. Based on veterinary care claims the incidence rate of epilepsy (including both idiopathic and symptomatic cases) was estimated to be 18 per 10,000 DYAR. Dogs were followed up until they were 10 (for life insurance claims) or 12 years of age (veterinary care claims). Among the 35 most common breeds in Sweden, the Boxer was at the highest risk of epilepsy with 60.3 cases per 10,000 DYAR, and also had the highest mortality rate of 46.7 per 10,000 DYAR (based on life insurance claims). Overall, males were at a higher risk than females (1.4:1). Median survival time (including euthanasia and death) after diagnosis was 1.5 years. In general, breeds kept solely for companionship lived longer after diagnosis than those kept for dual-purposes, such as hunting and shepherd and working breeds. The study demonstrates marked breed differences in incidence and mortality rates, which are assumed to reflect genetic predisposition to epilepsy.

Variation in training regimens in professional showjumping yards.

REASONS FOR PERFORMING STUDY: Training regimens of showjumping horses under field conditions are largely undocumented. OBJECTIVES: The aims of this study were to quantify and compare training regimens used in professional-level showjumping yards, with respect to time exercised and type of activity. STUDY DESIGN: Prospective cohort study. METHODS: A prospective 6-month cohort study of showjumping horses in 4 European countries (The Netherlands, Sweden, Switzerland, Great Britain) was designed to analyse training and health data, in yards with several horses in training and riders competing at professional level. Riders documented the daily frequency and duration of all physical activities of the horses. Variation in training routines were compared between riders, location and time. Mixed-models analysis was used to examine factors associated with total time exercised and time spent in flatwork. RESULTS: In 4 countries, the 31 participating riders trained 263 European Warmbloods. The total days at risk (e.g. days in which the horses were considered fit for exercise) was 39,262. Mean time spent in daily exercise, including ridden work, lungeing and treadmill exercise, varied between riders from 19-52 min/day at risk. There was considerable variation in activities and level of heavy work and light exercise, i.e. turnout. Total time exercised and time spent in flatwork differed with month, country and proportion of days lost to training. Low variation of activities was associated with decreased total time trained and increased time spent in flatwork. CONCLUSIONS: Riders at this elite professional level of showjumping used training regimens that vary substantially in time spent training and other physical activities and showjumping horses are challenged differently during training despite competing at the same level. Whether all training regimens prepare the horses equally for the demands of competition remains to be determined.

Days-lost to training and competition in relation to workload in 263 elite show-jumping horses in four European countries.

Orthopaedic, or other, injuries in sports medicine can be quantified using the 'days-lost to training' concept. Both the training regimen and the surface used in training and racing can affect the health of racehorses. Our aim was to associate 'days-lost to training' in elite-level show-jumpers to horse characteristics, training and management strategies, and the time spent working on various training and competition surfaces. We designed a longitudinal study of professional riders in four European countries. Data were recorded using training diaries. Reasons for days-lost were classified into non-acute and acute orthopaedic, medical, hoof-related, and undefined. We produced descriptive statistics of training durations, relative to type of training, surfaces used, and days-lost. We created zero-inflated negative-binomial random-effects models using the overall days-lost as outcome. In the whole dataset, duration variables related to training surfaces were analysed as independent. The Swedish data only were also used to test whether duration variables were related to competition surfaces. Thirty-one riders with 263 horses provided data on 39,028 days at risk. Of these, 2357 (6.0%) were days-lost (55% and 22% of these were due to non-acute and acute orthopaedic injuries, respectively) in 126 horses. In the all-country model, controlling for season, a significant variable was country. Switzerland and the UK had lower incidence-rate ratios (IR) compared to Sweden (IRs 0.2 and 0.03, respectively). Horses with previous orthopaedic problems had almost a doubled IR (1.8) of days-lost due to orthopaedic injury, compared to baseline. If the horse had jumping training more than 1 min per day at risk the IRs were 6.9-7 (compared to less than this amount of time); this was, however, likely an effect of a small baseline. Variation in training was a protective factor with a dose-response relationship; the category with the highest variation had an IR of 0.1. In the Swedish model, controlling for season, there was an association of year (IR 2.8 year 2010). Further, if the horse rested >17-25% of the days at risk, or >33% of the DAR2, had IRs 3.5 and 3.0, compared to less time. Horses ≥ 6 years had IRs of 1.8-2.0, compared to younger horses. Limited training use of sand surface was a risk-factor (IR 2.2; >4 ≤ 12 min/day at risk), compared to not training on sand. Training/competing on sand-wood was a protective factor (IRs 0.4-0.5) compared to not using this surface.

Effect of lungeing on head and pelvic movement asymmetry in horses with induced lameness.

Lungeing is an important part of lameness examinations, since the circular path enforced during lungeing is thought to accentuate low grade lameness. However, during lungeing the movement of sound horses becomes naturally asymmetric, which may mimic lameness. Also, compensatory movements in the opposite half of the body may mimic lameness. The aim of this study was to objectively study the presence of circle-dependent and compensatory movement asymmetries in horses with induced lameness. Ten horses were trotted in a straight line and lunged in both directions on a hard surface. Lameness was induced (reversible hoof pressure) in each limb, one at a time, in random order. Vertical head and pelvic movements were measured with body-mounted, uni-axial accelerometers. Differences between maximum and minimum height observed during/after left and right stance phases for the head (HDmax, HDmin) and pelvis (PDmax, PDmin) were measured. Mixed models were constructed to study the effect of lungeing direction and induction, and to quantify secondary compensatory asymmetry mechanisms in the forelimbs and hind limbs. Head and pelvic movement symmetries were affected by lungeing. Minimum pelvic height difference (PDmin) changed markedly, increasing significantly during lungeing, giving the impression of inner hind limb lameness. Primary hind limb lameness induced compensatory head movement, which mimicked an ipsilateral forelimb lameness of almost equal magnitude to the primary hind limb lameness. This could contribute to difficulty in correctly detecting hind limb lameness. Induced forelimb lameness caused both a compensatory contralateral (change in PDmax) and an ipsilateral (change in PDmin) hind limb asymmetry, potentially mimicking hind limb lameness, but of smaller magnitude. Both circle-dependent and compensatory movement mechanisms must be taken into account when evaluating lameness.

Movements of the horse's mouth in relation to horse-rider kinematic variables.

The aim of this study was to investigate the behavioural response of horses to rein contact and the movement of the riders' hands through analysis of data from horses ridden at two different head and neck positions. It was hypothesised that the riders' hand movements and rein tension would generate behavioural responses from horses and that these responses would be more marked when horses were ridden 'on the bit' than when unrestrained. Data were collected from seven dressage horse/rider combinations at sitting trot on a high speed treadmill. Kinematics were recorded using a 12-camera, infrared-based opto-electronic system. Three horses wore a rein tension meter. Behavioural registrations were made from video. Behavioural responses included lip movement, mouth movement, open mouth, change in ear position, head tilt and tail movement. Mouth movements were associated with the suspension phase of the trot. Head and neck position was non-significant in the final models, while rein tension and the distance between the rider's hand and the horse's mouth were related to mouth movements. Interactions between horses and riders are complex and highly variable.

Comparison of sampling sites and laboratory diagnostic tests for S. equi subsp. equi in horses from confirmed strangles outbreaks.

BACKGROUND: Strangles is a contagious equine-specific disease caused by Streptococcus equi subsp. equi. Unfortunately, detection of S. equi can fail in up to 40% of horses with strangles. Whereas recent molecular biologic methods and sampling techniques have improved recovery of S. equi optimal sampling methods and laboratory analyses remain ill-defined. OBJECTIVES: To determine the yield of S. equi from horses with acute strangles in confirmed outbreaks by field-sampling methods subjected to culture and biochemical identification, and real-time PCR directly and after culture. ANIMALS: Fifty-seven horses of varying breeds and ages from 8 strangles outbreaks. METHODS: Prospective study. Culture with biochemical identification and real-time PCR directly, and from culture, were performed on nasal swabs, nasopharyngeal swabs, and nasopharyngeal lavages. RESULTS: Real-time PCR directly from samples identified the highest number of infected horses, with 45/57 nasal swabs, 41/57 nasopharyngeal swabs, and 48/57 nasopharyngeal lavages S. equi positive. Biochemical identification (highest positives 22/57) was inferior to real-time PCR for S. equi recovery regardless of sampling method. Real-time PCR of nasopharyngeal lavage directly and after culture yielded 52/57 positives whereas direct real-time PCR of nasopharyngeal lavage combined with either nasopharyngeal swabs or nasal swabs yielded 53/57 positives. Three horses were negative on all samples. CONCLUSIONS AND CLINICAL IMPORTANCE: Nasopharyngeal lavage analyzed by a combination of real-time PCR directly and after culture or, alternatively, real-time PCR directly on a nasopharyngeal lavage and a nasal/nasopharyngeal swab can identify S. equi in over 90% of acute strangles cases.

Acquired equine polyneuropathy in Norway and Sweden: a clinical and epidemiological study.

REASONS FOR PERFORMING STUDY: Acquired equine polyneuropathy (AEP, also known as 'Scandinavian knuckling syndrome'), is a serious disease of unknown aetiology, which emerged clustering in horse farms in Sweden, Norway and Finland in the 1990s. Clinical and epidemiological data regarding the syndrome are scarce. OBJECTIVES: To describe the clinical and epidemiological findings and outcome in outbreaks of AEP and compare risk factors in affected and unaffected horses on affected farms in Norway and Sweden during 2007-2009. METHODS: Neurological examinations were performed and data collected regarding demography, usage, turning-out, feeding, prophylactic strategies and long-term outcome. RESULTS: Thirteen affected farms with 157 horses of various breeds, of which 42 were AEP cases, were studied. Typical digital extensor dysfunction and knuckling of pelvic limbs were noted in 34 definitive cases. Eight additional plausible cases had a severe, acute course of neurological disease. There were no signs of brain orcranial nerve dysfunction. Cases occurred from December to April, with new cases emerging within 100 days of the index case. Affected and unaffected horses were fed wrapped forage. Prevalence for AEP was 27% and case fatality 29%. The median duration of AEP in survivors was 4.4 months (1-17 months). Survivors returned to full work within 19 months (median 6.6 months). Acquired equine polyneuropathy was less prevalent in horses aged > 12 years and young horses had a higher chance of survival than older horses. Management factors did not differ between affected and unaffected horses. CONCLUSIONS: Acquired equine polyneuropathy is a potentially fatal neurological disease characterised by pelvic limb knuckling. Surviving horses returned to normal function after a long period of rest. Cases were clustered in farms during the winter/spring season. Wrapped forage was used in all farms. POTENTIAL RELEVANCE: The results provide valuable insights into the dinical examination, handling and prognosis of cases of AEP, an emerging neurological disease of unknown aetiology in horses.

Breed variations in the incidence of pyometra and mammary tumours in Swedish dogs.

Dogs enrolled in a Swedish insurance company (during 1995-2006) were studied for development of pyometra and mammary tumours (MTs), with special attention to breed and age. There were over 260,000 female dogs with over 1,000,000 dog-years at risk (DYAR) in the database, using data on bitches up to 10 years of age and 110 breeds with over 1000 DYAR. In total, 20 423 bitches were diagnosed with pyometra and 11,758 with MTs and 30,131 with either or both of the two diseases. The incidence rate (IR) for pyometra was 199 (95% CI 196-202), for MTs 112 (95% CI 110-114) and for either or both of the two diseases 297 (95% CI 294-301) dogs per 10,000 DYAR. The mean age of diagnosis pyometra was 7.0 years (SD ± 2.2), MTs 8.0 years (SD ± 1.6). In all breeds, the overall proportion of the bitches that developed disease by 10 years of age was for pyometra 19%, MTs 13%, and either or both of two diseases 30%. The top 10 breeds diagnosed with either or both of the two diseases were the Leonberger (73%), Irish Wolfhound (69%), Bernese Mountain Dog (69%), Great Dane (68%), Staffordshire Bull Terrier (66%), Rottweiler (65%), Bullterrier (62%), Doberman (62%), Bouvier des Flandres (60%), Airdaleterrier (60%). These data provide information of the combined disease incidence in a large number of different breeds. Breed variations in incidence rate suggests genetic components in disease development. Our study may be valuable in the search for genetic risk-factors or protective factors.