Explore the vast range of titles available.

The purpose of this prospective study was to evaluate the effects of single and repeated intra-articular administration of allogeneic, umbilical cord-derived, neonatal mesenchymal stem cells (MSC) in horses with lameness due to osteoarthritis (OA) of a metacarpophalangeal joint (MPJ). Twenty-eight horses were included. Horses were divided into two groups. Horses in group MSC1 received an MSC injection at M0 and a placebo injection at M1 (1 month after M0). Horses in group MSC2 received MSC injections at M0 and at M1. Joint injections were performed with a blinded syringe. Clinical assessment was performed by the treating veterinarian at M1, M2 and M6 (2 and 6 months after M0), including lameness evaluation, palpation and flexion of the joint. Radiographic examination of the treated joints was performed at inclusion and repeated at M6. Radiographs were anonymized and assessed by 2 ECVDI LA associate members. Short term safety assessment was performed by owner survey. A 2-month rehabilitation program was recommended to veterinarians. There was a significant improvement of the total clinical score for horses in both groups. There was no significant difference in the total clinical score between groups MSC1 and MSC2 at any time point in the study. There was no significant difference in the total radiographic OA score, osteophyte score, joint space width score and subchondral bone score between inclusion and M6. Owner-detected adverse effects to MSC injection were recorded in 18% of the horses. Lameness caused by OA improved significantly over the 6-month duration of the study after treatment with allogeneic neonatal umbilical cord-derived MSCs combined with 8 weeks rest and rehabilitation. There is no apparent clinical benefit of repeated intra-articular administration of MSCs at a 1-month interval in horses with MPJ OA when compared to the effect of a single injection.

Lameness detection in horses is a critical challenge in equine veterinary practice, particularly when symptoms are mild. This study aimed to develop a predictive system using a support vector machine (SVM) to identify the affected limb in horses trotting in a straight line. The system analyzed data from inertial measurement units (IMUs) placed on the horse’s head, withers, and pelvis, using variables such as vertical displacement and retraction angles. A total of 287 horses were included, with 256 showing single-limb lameness and 31 classified as sound. The model achieved an overall accuracy of 86%, with the highest success rates in identifying right and left forelimb lameness. However, there were challenges in identifying sound horses, with a 54.8% accuracy rate, and misclassification between forelimb and hindlimb lameness occurred in some cases. The study highlighted the importance of specific variables, such as vertical head and withers displacement, for accurate classification. Future research should focus on refining the model, exploring deep learning methods, and reducing the number of sensors required, with the goal of integrating these systems into equestrian equipment for early detection of locomotor issues.

This study aimed to document the effects of an eight hour journey on behavioural, clinical, haematological, environmental and respiratory parameters, and to identify possible associations between factors. Twelve horses underwent clinical examination, respiratory endoscopy with tracheal wash (TW) aspiration, and collection of venous and arterial blood before (BJ) and after the journey (AJ). TW were submitted for conventional quantitative bacteriological evaluation and genetic microbiome analyses. Behaviour was assessed in stables prior to transportation and throughout the journey. Transportation caused mild, but significant, effects on fluid and electrolyte balance and an acute phase response, characterized by neutrophilia, hyperfibrinogenaemia and hyperglobulinaemia. The proportion of neutrophils in TW, tracheal mucus and TW bacterial concentration was increased AJ, with preferential replication of Pasteurellaceae. Horse behaviour en route predicted clinical and respiratory outcomes. The frequency of stress related behaviours was greatest in the first hour of the journey, and balance-related behaviours were most common in the final hour of the journey. Horses which lowered their heads less frequently en route and showed more stress-related behaviours had higher physiological stress (serum cortisol and heart rate on arrival), increased tracheal mucus and inflammation scores, and higher TW bacterial concentration AJ (P<0.05). Six horses with abnormal lung auscultation AJ proved to have had higher tracheal inflammation scores at preloading (P = 0.017), an overall higher concentration of bacteria in their TW (P = 0.013), and an increased percentage of neutrophils in TW at five days AJ (P = 0.003) in comparison to the other horses. While transport-related health problems are multifactorial, clinical examination, including auscultation and endoscopic inspection of the lower respiratory tract before and after journey, and behavioural observation en route may identify animals at increased risk of transport associated respiratory disease.

Abstract Background The frequency, characteristics, and relationship with performance of arrhythmias occurring during high-intensity exercise in Thoroughbred racehorses remain poorly understood. Hypothesis/Objectives Describe the frequency, characteristics, and association with subsequent race performance of arrhythmias occurring during intense exercise. Animals Seventy-one racehorses competing in races sanctioned by the Hong Kong Jockey Club. Methods Risk-based case–control study. Single-lead ECGs were recorded during high-intensity trials using wearable devices. Ectopic depolarizations identified during warm-up, maximal exercise, and fast and slow recovery were characterized by frequency and morphology. Horses with ECG recordings obtained before a race were included. Race performance was classified as poor (finishing in the last 3 positions) or good (finishing in the first 3 positions). Associations between ECG variables and race performance were assessed using odds ratios. Results A total of 405 ECGs were recorded within 21 days before 1 or more race starts (82 poor- and 142 good-performance starts). Arrhythmias were detected in 73% and 81% of ECGs preceding good and poor performances, respectively. Ectopic beats during maximal exercise occurred in 57% of ECGs before good and in 70% before poor performances. The odds of performing poorly increased with each additional ectopic beat (odds ratio [OR], 1.15; 95% confidence interval [CI], 1.04-1.28; P = .01), and horses with any ectopic beat were nearly twice as likely to underperform (OR, 1.8; 95% CI, 0.86-3.81; P = .02). Conclusions and clinical importance Ectopic beats are common and adversely associated with athletic performance. Electrocardiographic monitoring during intense exertion might enable detection of clinically important arrhythmias.

Abstract Background Detailed characterization of arrhythmias can be performed by multiple catheter mapping; but this has not yet been explored in horses. Objectives Perform ultrasound-guided multiple catheter mapping of the right heart during sinus rhythm and right and left atrial pacing to identify activation patterns characteristic of the origin of ectopy. Obtain His signals and effective refractory periods (ERP). Animals Eight healthy adult horses. Methods Experimental study. Recording catheters were placed at the terminal crest, intervenous tubercle, caudal vena cava, and coronary sinus. Right atrial pacing was performed in standing, sedated horses from each catheter and from the cranial vena cava, right atrial appendage, and right atrial free wall. Left atrial pacing was performed during general anesthesia at the four pulmonary vein ostia, left atrial appendage, and interatrial septum. Atrial activation patterns were recorded from the catheters during sinus rhythm and during pacing at the different sites. During sinus rhythm, the His bundle was recorded, and ERP at different sites was determined. Results Characteristic activation maps during sinus rhythm and pacing were identified. Late coronary sinus activation indicated ectopy originating from the right atrium or ostium III. The direction of coronary sinus electrode activation aided in differentiating left atrial ectopy locations. His signals were recorded in 5/8 horses. Atrial ERP varied between 170 and 420 ms with inter-horse and intra-horse variation. Conclusions and Clinical Importance Performing an electrophysiological study in horses, including multiple catheter recording, was feasible. Pacing-induced ectopy resulted in characteristic activation patterns, which might aid in identifying the site of atrial ectopy.

Tendon injuries are a common age-related degenerative condition where current treatment strategies fail to restore functionality and normal quality of life. This disease also occurs naturally in horses, with many similarities to human tendinopathy making it an ideal large animal model for human disease. Regenerative approaches are increasingly used to improve outcome involving mesenchymal stem cells (MSCs), supported by clinical data where injection of autologous bone marrow derived MSCs (BM-MSCs) suspended in marrow supernatant into injured tendons has halved the re-injury rate in racehorses. We hypothesized that stem cell therapy induces a matrix more closely resembling normal tendon than the fibrous scar tissue formed by natural repair. Twelve horses with career-ending naturally-occurring superficial digital flexor tendon injury were allocated randomly to treatment and control groups. 1X10(7) autologous BM-MSCs suspended in 2 ml of marrow supernatant were implanted into the damaged tendon of the treated group. The control group received the same volume of saline. Following a 6 month exercise programme horses were euthanized and tendons assessed for structural stiffness by non-destructive mechanical testing and for morphological and molecular composition. BM-MSC treated tendons exhibited statistically significant improvements in key parameters compared to saline-injected control tendons towards that of normal tendons and those in the contralateral limbs. Specifically, treated tendons had lower structural stiffness (p<0.05) although no significant difference in calculated modulus of elasticity, lower (improved) histological scoring of organisation (p<0.003) and crimp pattern (p<0.05), lower cellularity (p<0.007), DNA content (p<0.05), vascularity (p<0.03), water content (p<0.05), GAG content (p<0.05), and MMP-13 activity (p<0.02). Treatment with autologous MSCs in marrow supernatant therefore provides significant benefits compared to untreated tendon repair in enhancing normalisation of biomechanical, morphological, and compositional parameters. These data in natural disease, with no adverse findings, support the use of this treatment for human tendon injuries.

The aim of this study was to determine whether horses exhibiting unilateral hindlimb lameness unload (rest) the lame limb more than the contralateral limb. The resting/unloading of the hindlimbs and the time spent lying down were measured using accelerometers. Ten non-lame horses and 20 lame horses were recruited for participation and monitored for 11 h overnight with accelerometers (MSR145, sampling rate: 1 Hz, and measuring range: ±15 g) attached to the lateral metatarsal and metacarpal regions of each limb. Metatarsal and metacarpal orientation were used to determine whether the limb was unloaded (rested) or loaded, respectively, or whether the horses were lying down. The relation of resting time between non-lame and lame limbs (non-lame/lame: 0.85 ± 1.2) of the lame horses differed significantly (p = 0.035) from that of the non-lame horses (right/left: 1.08 ± 0.47). Non-lame horses rested their hindlimbs evenly (left: 15 ± 10%; right: 17 ± 16%). Horses with unilateral hindlimb lameness unloaded the lame limb longer (lame limb: 61.8 ± 25.3%, non-lame limb: 38.2 ± 25.3%) than their contralateral limb. The lame horses (13 ± 11%) lay down longer (p = 0.012) than the non-lame horses (3 ± 6%). The degree of lameness determined by the participating veterinarians (Vet Score) (r = −0.691, p < 0.01) and the asymmetry evaluated by the lameness locator (ALL) (r = −0.426, p = 0.019) correlated with the resting ratio (rest time ratio). Both factors were also correlated with the time spent lying down (Vet Score (r = 0.364, p = 0.048) and the ALL (r = 0.398, p = 0.03)). The ALL and VET Score were significantly correlated (r = 0.557, p = 0.01). The results of this study provide a good baseline for future research into how individual resting patterns may help to detect pain.

Abstract Background Paroxysmal atrial fibrillation (pAF) occurs sporadically in horses and has been implicated in poor performance. Diagnosis in large numbers of horses has previously relied on post-exercise ECGs. Hypothesis/Objectives Describe pAF-like bursts detected during exercise and determine their effect on speed, stride, and racing performance. Methods Retrospective case control study, evaluating records of exercising ECG consultations referred to a specialist practice to identify horses with pAF-like bursts. Controls were selected from the same population as racehorses with normal exercising ECGs. Results Eleven cases with pAF-like bursts and 10 controls with normal exercising ECGs were identified, among 100 ECG consultations. The pAF-like bursts occurred in all horses during peak exercise (60-68 km/h; heart rate, 206-217 beats per minute), with normal ECGs during warm-up and recovery. The duration of pAF-like bursts ranged from 10 to 90 s, returning to normal rhythm in all horses before the end of peak exercise. During the pAF-like bursts, 5 horses decelerated, 3 accelerated, and in 3 horses speed was unaffected. Immediately after the pAF-like bursts, 5 horses slowed down, 4 horses did not change their speed and 2 horses accelerated. Root mean square of successive differences (RMSSD) and standard deviation of normal-to-normal intervals (SDNN) during peak exercise were high in all horses. During recovery, RMSSD was normal and SDNN was high in both the pAF-like burst and control horses. Racing performance after the pAF-like burst was available for 8 horses and 7 did not race successfully. Conclusion and clinical importance Paroxysmal atrial fibrillation-like bursts occurred during high-intensity exercise in racehorses and may be missed on post-exercise ECGs. These findings emphasize the value of peak-effort ECGs for detecting transient arrhythmias.

Human asthma is a complex and heterogeneous disorder characterized by chronic inflammation, bronchospasm and airway remodeling. The latter is a major determinant of the structure-function relationship of the respiratory system and likely contributes to the progressive and accelerated decline in lung function observed in patients over time. Corticosteroids are the cornerstone of asthma treatment. While their action on inflammation and lung function is well characterized, their effect on remodeling remains largely unknown. An important hindrance to the study of airway remodeling as a major focus in asthma research is the lack of reliable non-invasive biomarkers. In consequence, the physiologic and clinical consequences of airway wall thickening and altered composition are not well understood. In this perspective, equine asthma provides a unique and ethical (non-terminal) preclinical model for hypothesis testing and generation. Severe equine asthma is a spontaneous disease affecting adult horses characterized by recurrent and reversible episodes of disease exacerbations. It is associated with bronchoalveolar neutrophilic inflammation, bronchospasm, and excessive mucus secretion. Severe equine asthma is also characterized by bronchial remodeling, which is only partially improved by prolonged period of disease remission induced by therapy or antigen avoidance strategies. This review will focus on the similarities and differences of airway remodeling in equine and human asthma, on the strengths and limitations of the equine model, and on the challenges the model has to face to keep up with human asthma research.

Abstract Background Sudden cardiac death is common in racehorses. Factors associated with the QT interval that could predispose to fatal cardiac arrhythmias are unknown. Cardiac restitution, expressed as a ratio of QT/TQ, has been used in humans to assess arrhythmia risk but has not been described in horses during maximal intensity exercise. Hypothesis/Objective Describe factors associated with the QT interval and cardiac restitution ratio (CRR) in clinically normal Standardbred racehorses under race-day conditions. Animals Archival electrocardiograms from 42 Standardbred horses during live racing in Ontario. Methods Observational study performing an automated cardiac restitution analysis. Cardiac cycles were obtained from rest, non-race exercise, non-race recovery, live racing, and post-race recovery periods. Multivariable linear regression analysis was performed with both QT interval and CRR as outcomes of interest. Results Analysis of 3827 sequential pairs of cardiac cycles was performed. Exercise period and RR interval were highly associated with both QT interval and CRR. Other significant associations varied by exercise period and included: racing gait, sex, age, whether the horse received furosemide, and whether the horse experienced complex ventricular arrhythmias after racing. Interactions between gait and furosemide, and sex and gait were also significant. Conclusions and Clinical Importance An automated cardiac restitution analysis is feasible in exercising racehorses. The QT-RR interval relationship is multifactorial, and there are numerous significant associations that must be considered to interpret changes in QT interval and CRR in horses.