Horse-level risk factors for fatal distal limb fracture in racing Thoroughbreds in the UK
ABSTRACT Fractures below the level of the radius or tibia (distal limb fractures) are the most common cause of equine fatality on UK racecourses; however, little is known about their epidemiology or aetiology. Identification of risk factors could enable intervention strategies to be designed to reduce the number of fatalities.
To identify horse-level risk factors for fatal distal limb fracture in Thoroughbreds on UK racecourses.
A case-control study design was used. Fractures in case horses were confirmed by post mortem examination and 3 matched uninjured controls were selected from the race in which the case horse was running. One hundred and nine cases were included and information was collected about previous racing history, horse characteristics and training schedules. Conditional logistic regression was used to identify the relationship between a number of independent variables and the likelihood of fracture.
Horses doing no gallop work during training and those in their first year of racing were at significantly increased risk of fracture on the racecourse. Case horses were also more likely to have trained on a sand gallop, i.e. a gallop described by trainers as being primarily composed of sand.
Modifications to training schedules, specifically within the first year of racing, may have a large impact on the risk of fatal distal limb fracture on the racecourse. Horses should do some gallop work in training and our results suggest that the minimum distance galloped should be between 805-2012 m (4-10 furlongs)/week.
The information from this study can be used to alter training schedules in an attempt to reduce the incidence of fatal distal limb fracture in Thoroughbred racehorses. Training should include some gallop work, and further studies, recording the exact level of work, will help to identify an optimum range of training speeds and distances which will reduce the liklihood of catastrophic fracture on the racecourse.
- SourceAvailable from: Tim Parkin
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- "The frequency and severity of MSC create a substantial financial burden for the racing industry, compromise equine welfare and create negative publicity for the sport. Many previous studies have attempted to identify risk factors for MSC in racehorses (see, for example, Stephen et al., 2003; Ely et al., 2004; Parkin et al., 2004a; Pinchbeck et al., 2004; Jacklin and Wright, 2012). These studies varied in many ways, including case definition, identity of the target population, and whether diagnoses were made in racing and/or training. "
ABSTRACT: A retrospective cohort study of important musculoskeletal conditions of Thoroughbred racehorses was conducted using health records generated over a 15 year period (n = 5062, 1296 sires). The prevalence of each condition in the study population was: fracture, 13%; osteoarthritis, 10%; suspensory ligament injury, 10%; and tendon injury, 19%. Linear and logistic sire and animal regression models were built to describe the binary occurrence of these musculoskeletal conditions, and to evaluate the significance of possible environmental risk factors. The heritability of each condition was estimated using residual maximum likelihood (REML). Bivariate mixed models were used to generate estimates of genetic correlations between each pair of conditions. Heritability estimates of fracture, osteoarthritis, suspensory ligament and tendon injury were small to moderate (range: 0.01–0.20). Fracture was found to be positively genetically correlated with both osteoarthritis and suspensory ligament injury. These results suggest that there is a significant genetic component involved in the risk of the studied conditions. Due to positive genetic correlations, a reduction in prevalence of one of the correlated conditions may effect a reduction in risk of the other condition.The Veterinary Journal 06/2013; 198(3). DOI:10.1016/j.tvjl.2013.05.002 · 2.17 Impact Factor
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- "In contrast, Cohen and coworkers reported that injured horses had undergone significantly less cumulative high speed exercise than control horses during a 1–2 month period prior to the race in which the injury happened (Cohen et al. 2000). Such conflict may be due to differences in studies populations under different racing jurisdictions or could be as a result of differences in case definitions and study design (Cohen et al. 2000; Parkin 2002). "
ABSTRACT: Orthopaedic injury is common in the racing Thoroughbred and is a cause of both economic loss to the industry, as well as being an obvious welfare issue. Fatal injuries sustained during racing are an obvious major concern and it is important that all is done to reduce their frequency. As a consequence of the importance of these causes of horse morbidity and mortality, the Horserace Betting Levy Board in the UK has invested considerable resources into research in recent years in this area in an attempt to decrease the frequency of such injuries. This review summarises current knowledge relating to epidemiological investigations relating to fractures, falling and fatalities in the racing Thoroughbred. Studies identify the importance of track surface conditions, the importance of pre-existing orthopaedic pathology, as well as issues relating to the horse's past training and racing experience as important determinants of both injury and death. Such findings can now be used to develop interventions to reduce racehorse injury and death for the benefit of both the industry and the horse.Equine Veterinary Journal 09/2011; 43(6):643-9. DOI:10.1111/j.2042-3306.2011.00457.x · 2.37 Impact Factor
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- "Several epidemiological studies have been published investigating risk factors for wastage and/or injuries in Thoroughbred racehorses (Rossdale et al. 1985, Parkin et al. 2004a,b, Verheyen and Wood 2004), event horses (Singer et al. 2003; Murray et al. 2006; Singer et al. 2008) and dressage horses (Murray et al. 2010). Anecdotal information suggests that elimination rates at endurance rides vary between countries and eliminations occur more frequently at higher speeds; however, to date, no large scale evidence-based data are available to support these hypotheses. "
ABSTRACT: Endurance is the fastest growing Féderation Équestre International (FEI) discipline and the large number of eliminations on veterinary grounds needs to be investigated. To document elimination rates and explore potential risk factors for elimination due to lameness or metabolic reasons in 9 countries representing 5 continents. Data for rides of ≥ 100 km ('elite endurance rides') in Australia, France, Italy, South Africa, Spain, United Arab Emirates (UAE), UK, Uruguay and USA were collected from the FEI website. Data were collected for all started horses on the country, number of horses in the class, ride distance, class (e.g. young rider class) and the average speed of the winning horse. Retirements, eliminations for lameness, metabolic and other reasons were recorded. Uni- and multivariable logistic regression models were used to assess the effect of country, number of horses in the class, ride distance and young rider class on 2 outcomes (elimination for lameness and metabolic reasons). Data for 157 classes at 91 events were analysed. The UAE had the highest number of entries (1497), followed by France (1029) and Spain (408). Of 4326 started horses, 46.0% finished the ride. Lameness was the most common cause of elimination in all countries followed by metabolic reasons (69.2 and 23.5% of all eliminations, and 31.8 and 10.8% of all started horses, respectively). Eight percent of horses were retired by the rider, having passed the veterinary examination. In multivariable analysis, the risk of elimination for lameness was associated with the country in which the ride was held, and the risk significantly increased (OR = 1.60) for horses competing in rides with ≥ 80 entries. The risk of elimination for metabolic reasons was also significantly associated with the country in which the ride was held and the risk significantly increased (OR = 2.17) for horses competing in rides with ≥ 100 entries in the multivariable analysis. Elimination rates vary between countries, with lameness being the most common reason for elimination globally. Analysis of retrospective data showed country and number of started horses to be risk factors for elimination due to lameness and for elimination due to metabolic disorders. A prospective study is needed to assess the effects of environmental conditions, individual horse speed and other variables on the risk of specific causes of elimination.Equine Veterinary Journal 11/2010; 42(38):637-43. DOI:10.1111/j.2042-3306.2010.00220.x · 2.37 Impact Factor