Search

OBJECTIVE To verify the existence of intertransverse joints (ITJs) in young foals. ANIMALS 11 warmblood foals. PROCEDURES Postmortem examination of the lumbar area in foals < 200 days old using CT, MRI, dissection, and histomorphology. Data were analyzed with descriptive statistics. RESULTS Age of foals varied between 1 and 200 days (median, 11 days). Ten foals had 6 lumbar (L) vertebrae, and 1 foal had 5. All 11 foals, irrespective of age, had ITJs between the first sacral and last lumbar vertebrae and between the last and second-to-last lumbar vertebrae. In 6 foals (all with 6 L vertebrae), ITJs also existed between the fourth and fifth L vertebra. One foal, also with 6 L vertebrae, additionally had a unilateral (right) ITJ between the transverse processes of the third and fourth L vertebra. Based on CT, width of ITJs was seemingly greater in young (< 1 month old) foals because of the incomplete ossification of the transverse processes. The ITJs were confirmed and further characterized by MRI, dissection, and histomorphology. CLINICAL RELEVANCE ITJs already exist in very young warmblood foals and are present at birth. During the first months of life, these juvenile ITJs develop similarly to other synovial joints with increasing ossification and concomitant decrease of thickness of the cartilage layer. Knowledge of the presence of these ITJs in young animals is clinically relevant, as they should be recognized as nonpathologic when for instance a young foal is presented for presumed arthropathy and examined with advanced imaging techniques.

An established lipopolysaccharide (LPS) model previously described in Warmbloods, was inconsistent in Standardbred horses, where lameness was not detected despite the presence of synovitis. The present study aimed to determine the dose of LPS from E. coli O55:B5 required to induce mild to moderate lameness following middle carpal joint injection in Standardbred horses and to quantitate the induced lameness over time, with and without anti-inflammatory pre-treatment. In a baseline trial, eight healthy, clinically sound Standardbred horses were used in a rule-based dose-escalation design trial, starting at a dose of 10 endotoxin units (EU). Lameness at trot was evaluated visually and quantitatively (using an inertial-sensor system and pressure plate analysis). Synovial fluid aspirates were analysed for total nucleated cell counts, total protein and prostaglandin E2 (PGE2). Following 2 months wash-out, the effective LPS-dose determined in the baseline trial was used to evaluate the effect of anti-inflammatory treatment. A mixed model for repeated measures with horse as random effect was used for analysis. After injection of 10 EU LPS, the desired degree of lameness was observed in the baseline trial, with maximal lameness at post-injection hour (PIH) 4, followed by a rapid decline and return to baseline by PIH 48. No lameness was observed following pre-treatment with meloxicam. In synovial fluid, PGE2 was significantly higher at PIH 8 and PIH 24 in the baseline trial compared with following meloxicam pre-treatment. In conclusion, injection of the middle carpal joint with 10 EU LPS consistently induces a transient lameness and synovitis in Standardbred horses.

At Federation Equestre Internationale (FEI) competitions, horses undergo veterinary inspection for judgement of ‘fit-to-compete’. However, FEI Veterinary Delegates (VDs) often differ in opinion. The aim of the present study was to evaluate intra- and inter-observer agreements of fit-to-compete judgement and compare these with objective gait analysis measurements. Twelve horses were evaluated by three experienced VDs and one veterinary specialist and video-recorded for re-evaluation later. Simultaneously, quantitative gait analysis measurements were acquired. Inter-observer agreement during live evaluations was fair (κ = 0.395, 58% agreement). Intra-observer agreement between live observations and videos at one and 12 months was 71% and 73% respectively. Sensitivity and specificity of motion symmetry measured with quantitative gait analysis system were 83.3% and 66.7% respectively, against the consensus of all observers as a reference. These findings might suggest that more VDs should be used to adequately judge fit-to-compete. Quantitative-gait-analysis may be useful to support decision making during fit-to-compete judgement.

Clinical assessment of spinal motion in horses is part of many routine clinical exams but remains highly subjective. A prerequisite for the quantification is the assessment of the expected normal range of motion and variability of back kinematics. The aim of this study was to objectively quantify spinal kinematics and between-measurement, -surface and -day variation in owner-sound horses. In an observational study, twelve owner-sound horses were trotted 12 times on four different paths (hard/soft straight line, soft lunge left and right). Measurements were divided over three days, with five repetitions on day one and two, and two repetitions on day three (recheck) which occurred 28-55 days later. Optical motion capture was used to collect kinematic data. Elements of the outcome were: 1) Ranges of Motion (ROM) with confidence intervals per path and surface, 2) a variability model to calculate between-measurement variation and test the effect of time, surface and path, 3) intraclass correlation coefficients (ICC) to determine repeatability. ROM was lowest on the hard straight line. Cervical lateral bending was doubled on the left compared to the right lunge. Mean variation for the flexion-extension and lateral bending of the whole back were 0.8 and 1 degrees. Pelvic motion showed a variation of 1.0 (pitch), 0.7 (yaw) and 1.3 (roll) degrees. For these five parameters, a tendency for more variation on the hard surface and reduced variation with increased repetitions was observed. More variation was seen on the recheck (p

Application Understanding muscular adaptations could inform objective lameness-detection for early diagnosis/treatment,\ud ultimately serving to detect sub-clinical issues in supposed healthy horses and to reduce pain/ incapacity in lame horses.\ud Introduction The prevalence and impact of lameness on equine welfare has led to extensive research, which has\ud biomechanically analysed lameness-related alterations in movement. Despite this, limited information is available about\ud adaptive muscle activity that facilitates movement during lameness. Surface electromyography (sEMG) is a non-invasive\ud method for quantifying muscle activity. However, no equine studies have employed sEMG to compare inherent and\ud adaptive activity during non-lame and standardised lameness conditions, respectively. The aim of this preliminary study\ud was to compare Triceps Brachii (TB) muscle activity in horses before and after induced forelimb (FL) lameness, using\ud sEMG data.\ud Material and methods Six clinically non-lame horses (5 mares, 1 stallion, age: 7.0±3.7 years, height: 162.3±4.0 cm, body\ud mass: 572.7±45.8 kg) were used. sEMG sensors (Delsys Trigno, Delsys Inc.) were attached bilaterally to locations above\ud TB (long head), that were prepared by removing all hair and cleaning with isopropyl alcohol. Retro-reflective markers were\ud attached to anatomical landmarks for quantitative lameness evaluation (QHorse, Qualisys AB) and gait event detection.\ud sEMG (2000 Hz) and 3D kinematic (200 Hz) data were synchronously collected from horses during in-hand trot trials,\ud conducted on a straight, hard surfaced runway before (baseline) and after FL lameness induction. Baseline data were\ud initially collected, then temporary, mild FL lameness (2-3/5 AAEP Lameness Scale) was induced using mechanical bolt\ud pressure, applied to the tip of the frog and monitored by qualified veterinarians (T.S., F.S.B.) using a modified horseshoe\ud (Merkens and Schamhardt, 1988). Left and right FL lameness induction were randomised. Following data collection, the\ud bolt/ sole pressure was removed and no horses showed adverse reactions to lameness inductions, or residual lameness. For\ud stride segmentation, gait events were detected using kinematic data that were low-pass filtered (Butterworth 4th order, 10\ud Hz cut-off) and analysed in accordance with the methods described by Holt et al. (2017). To quantify lameness, MinDiff\ud was calculated using poll vertical displacement data, where healthy horses exhibit MinDiff between -6 – 6mm and left and\ud right FL lameness are exhibited as more positive and negative values, respectively (Rhodin et al., 2016). Raw sEMG\ud signals were DC-offset removed, high-pass filtered (Butterworth 4th order, 40 Hz cut-off) (St. George et al., 2018), and fullwave\ud rectified. Integrated EMG (iEMG) and average rectified value (ARV) were calculated using stride duration as\ud temporal domain. To reduce inter-subject variability, iEMG and ARV from each horse were normalised to the maximum\ud value observed for each limb (left/ right FL) across all strides from the baseline condition. Data from the “lame” and “nonlame”\ud limb were grouped, according to the limb where lameness was induced. A 2x2 repeated measures ANOVA was used\ud to compare muscle activity between limb (lame, non-lame) and condition (baseline, induced FL lameness). Post-hoc\ud analyses using Bonferroni correction were performed where significant main effects were found.\ud Results Mean ± sd MinDiff were baseline:-1.8 ± 8.7 mm, left FL lameness induction:-55.3 ± 34.1 mm, right FL lameness:\ud 56.8 ± 17.9 mm. Significant interactions between limb and condition were found for iEMG (p < 0.05, n2=0.74) and ARV (p\ud < 0.05, n2=0.75). Post hoc analyses of iEMG and ARV data revealed muscle activity was significantly higher in the lame\ud limb (p < 0.05) and significantly lower in the non-lame limb (p < 0.01) during the induced FL lameness condition.\ud Conclusion Preliminary findings reveal neuromuscular adaptations in TB during induced FL lameness. Significant\ud increases in stance duration have been reported during FL lameness (Weishaupt et al., 2006). Therefore, significant\ud increases in lame limb muscle activity may be due to prolonged stabilisation of the shoulder and elbow joints, as a\ud compensatory mechanism of gait adaptation to lameness. Further investigations of additional muscles and chronic lameness\ud cases are required to determine whether sEMG can provide a complimentary tool for objective lameness detection.

Extracellular vesicle (EV) concentration, characteristics and function in equine synovial fluid (SF) during normal growth and development has not previously been studied. Isolation of EVs was performed in SF from three healthy foals and two adult horses by differential ultracentrifugation (10,000 g and 200,000 g); EVs were purified by sucrose density gradient floatation and analysed by high-resolution flow cytometry (FCM), buoyant density and western blotting. Additionally, repeated biomarker analysis of sulphated glycosaminoglycans (GAG), matrix metalloproteinase (MMP), C-terminal crosslinked telopeptide type II collagen (CTX-II), collagenase cleaved neopeptide type II collagen (C2C) was performed in SF from 10 foals and six adult horses. In contrast with the quantitative EV profile, the biomarker profile in SF from juvenile joints was substantially different from that in SF from adult animals. However, there were qualitative differences in the high-resolution FCM scatter plots. Future in-depth functional analyses may reveal differences between juvenile and mature EVs in SF.