A Ridden-Horse-Ethogram has been developed to differentiate between nonlame and lame horses, and lame horses before and after diagnostic analgesia has abolished musculoskeletal pain, based on video recordings. The objective of this prospective, observational study was to compare real-time application of the Ridden-Horse-Ethogram with analysis of video recordings of the horses by a trained assessor and to determine whether veterinarians, after preliminary training, could apply the ethogram in real time in a consistent way and in agreement with an experienced assessor. Ten equine veterinarians (after preliminary training) and an experienced assessor applied the ethogram to 20 horse-rider combinations performing a purpose-designed dressage test (8.5 min). The horses were a convenience sample, in regular work, and capable of working 'on the bit'. Video recordings of the test were analysed retrospectively by the experienced assessor. Lameness or abnormalities of canter, saddle fit, the presence of epaxial muscle tension/pain and rider skill level were determined by independent experts. The results were that 16 horses were lame; 11 had an ill-fitting saddle; 14 had epaxial muscle tension/pain. The expert determined total scores of 3-6/24 for the nonlame horses; two lame horses scored 3 and 6; 14 lame horses scored 8-16. There was no significant difference in real-time scores and video-based scores for the experienced assessor. There was good agreement between the expert's scores and the mean test observer scores. There was excellent consistency in overall agreement among raters (Intraclass correlation 0.97, P<0.001). There was a significant difference between ethogram scores according to lameness status for real-time (P = 0.017) and video (P = 0.013) observations by the experienced assessor and for the test observers' mean (P = 0.03). There was no effect of muscle pain, saddle fit or rider skill on behaviour. It was concluded that the ethogram was applied consistently by veterinarians with differentiation between nonlame and most lame horses. After appropriate training in its application, the ethogram may provide a useful tool for determining the presence of musculoskeletal pain in horses performing poorly.moderate agreement in application of the Ridden Horse Ethogram among veterinarians to determine the presence of 24 behavioural markers; and (3) there would be a significant difference in the ethogram scores for the nonlame and lame horses. Materials and methodsThis was a prospective, observational study which was approved by the Clinical Ethical Review Committee of the Animal Health Trust (AHT-50-2017). 23. Rearing (both forelimbs off the ground) 24. Bucking or kicking backwards (one or both hindlimbs) Assessments were made in walk, trot and canter and on the left and right reins. A total behaviour score of ≥8 (out of 24) is likely to indicate the presence of musculoskeletal pain.

Skeletal scintigraphy is an established imaging modality, however, its validity as a diagnostic test in lame or poorly performing sports horses has not been determined. The objective of this retrospective cross-sectional analytical study was to determine the accuracy of skeletal scintigraphy as an indiscriminate screening test in sports horses. All sports horses that underwent scintigraphic examination between March 2008 and December 2014 for which a definitive diagnosis was reached were included. Examinations were evaluated blindly. Characteristics of increased radiopharmaceutical uptake were recorded and subjectively categorized as possibly relevant or non-relevant. Kappa statistics were used to assess agreement between test results and final diagnosis. There were 1222 positive clinical diagnoses in 480 horses, of which 687 regions (56.4%) had no associated increased radiopharmaceutical uptake and 99 regions (8.1%) had non-relevant increased radiopharmaceutical uptake. The sensitivity of increased radiopharmaceutical uptake for identification of final diagnosis was low (43.8%) and specificity was high (94.0%). The agreement was fair (κ = 0.36). Relevance categorization improved the test; the sensitivity for final diagnosis was low (35.7%), specificity was high (98.9%), and the agreement was moderate (κ = 0.45). The agreements of increased radiopharmaceutical uptake and relevance categorization with final diagnosis were only substantial for feet (κ = 0.67 and κ = 0.66, respectively) and proximal aspect of the forelimb (elbow, shoulder, and scapula combined) (κ = 0.69 and 0.78, respectively). Scintigraphic examination is unlikely to lead to a full and correct diagnosis of the cause(s) of lameness or poor performance in sports horses when used as an isolated or indiscriminate screening tool.

There is good correlation between increased radiopharmaceutical uptake anywhere in the feet of sports or leisure horses and the presence of foot pain. However, low sensitivity of scintigraphy for identifying lesions contributing to foot pain as determined by magnetic resonance imaging (MRI) has been reported. The aim of this retrospective, cross-sectional, analytical study was to assess the accuracy of scintigraphy for identifying the cause(s) of foot pain, using MRI as the reference standard. Sports and leisure horses that underwent both skeletal scintigraphy and MRI of the front feet between March 2008 and December 2014 and for which a definitive diagnosis of the cause(s) of front foot pain was reached were included (121 feet of 70 horses). Imaging studies were evaluated retrospectively, blindly. Agreements between scintigraphic localization of increased radiopharmaceutical uptake and subjective categorization of lesions with MRI diagnosis were assessed using Kappa statistics (κ). Measures of diagnostic accuracy were calculated. Sensitivity of increased radiopharmaceutical uptake varied among regions (31.8-76.2%) but specificity was at least high for all (84.6-100%). Agreements between both scintigraphy measures and MRI diagnosis were substantial for the distal phalanx (palmar processes and body) (κ = 0.77 and κ = 0.74, respectively), and ungular cartilages and chondral ligaments (κ = 0.62, for both). When all regions were combined, agreements of increased radiopharmaceutical uptake (κ = 0.49) and relevance categorization (κ = 0.45) with MRI diagnosis were moderate. In conclusion, skeletal scintigraphy does not meet the minimum reliability level for a diagnostic test, but is reliable for identification of osseous trauma to the distal phalanx and ungular cartilages.

Background: There is a lack of understanding of the pathological and/or physiological nature of lumbosacral region pain.Objectives: To describe the gross variations of the osseous and soft tissues of the lumbosacral region and report the histological findings of sections of nerve tissue in affected and control horses. Study design:Descriptive post-mortem case series.Methods: All horses had undergone full clinical and gait assessment, including ridden exercise. Horses with a substantial response to infiltration of local anaesthetic solution around the sacroiliac joint regions were included in the affected group (n = 27).Horses for which the source(s) of pain was confirmed by diagnostic anaesthesia to be distant to the lumbosacral region were included in the control group (n = 5). The pelvic regions were isolated and the soft tissues were assessed grossly. Sections of the lumbosacral plexus and cranial gluteal, sciatic and obturator nerves were examined histologically. The osseous specimens were evaluated for anatomical variants and abnormalities. Data were analysed using descriptive statistics.Results: Gross discolouration of the sciatic or obturator nerves was observed in 7 (26%) affected and no control horses. Grade 3/3 histological abnormality scores were assigned in 22% of nerve sections from affected horses compared with 3% from control horses.Several osseous variants (bifid sacral spinous processes, straight-shaped sacroiliac joint surface, short arrow-shaped sacral alae, left-right asymmetry of sacral alae, sacral curvature, absence of the fourth to fifth and ankylosis of the fifth to sixth lumbar articular process joints, left-right asymmetry of caudocranial position of the fourth to fifth and lumbar-sacral articular process joints) and abnormalities (sacroiliac enthesopathy, extra ventral sacroiliac joint surface, lumbosacral symphyseal periarticular modelling, lumbosacral intertransverse joint pitting lesions) were more frequently observed in affected horses. Main limitations:Both control and affected horses may have had preclinical abnormalities.Conclusions: Lumbosacral region pain may reflect the presence of a number of pathological changes. Neural pain may play an important role in some horses.

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