Description of veterinary events and risk factors for fatality in National Hunt flat racing Thoroughbreds in Great Britain (2000-2013).

BACKGROUND: No large-scale studies have described veterinary events occurring in National Hunt (NH) flat racing or investigated risk factors for fatality in this race type. OBJECTIVES: To describe injuries and conditions requiring veterinary attendance on race day and to determine risk factors for racehorse fatality in NH flat racing in Great Britain. STUDY DESIGN: Retrospective cohort study (2000-2013). METHODS: Information from all NH flat races held over the study period, including horse, race and veterinary event report details, was combined. Veterinary events were described by type and anatomical structure(s) affected. Incidence per 1000 starts were calculated for all veterinary events and by event group, and stratified by certain horse- and race-level variables. Risk factors for fatality were determined using multivariable logistic regression modelling. RESULTS: Over the 14-year study period, 544 veterinary events were recorded, providing an overall incidence of 13.0 events per 1000 starts. The most common events were bone injuries (23.5%) and tendon or ligament injuries (16.4%). A fatal outcome was recorded for 117 horses (21.5% of all events), resulting in an incidence of 2.9 deaths per 1000 starts. Odds of fatality were 4.33 (95% confidence interval [CI] 1.59-11.82; P = 0.02) times higher in races restricted to conditional jockeys compared to those that were not. Horses starting in their first race experienced 1.44 (95% CI 1.00-2.08; P = 0.05) times the odds of death compared to those that had raced before. MAIN LIMITATIONS: Classification of veterinary events frequently relied upon presumptive diagnosis. CONCLUSIONS: This study provides a benchmark for the ongoing surveillance of veterinary events in NH flat racing. These results support the phasing out of NH flat races restricted to conditional jockeys and highlight the need for further work to establish why NH flat racing Thoroughbreds competing in their first race are at increased risk for death.

Descriptive epidemiology of veterinary events in flat racing Thoroughbreds in Great Britain (2000 to 2013).

BACKGROUND: To date, no large scale studies have reported race-day events requiring veterinary attention in British Thoroughbreds racing on the flat. Quantifying and describing common injuries and health conditions affecting racehorses will enable targeted risk factor analysis aimed at reducing their occurrence. OBJECTIVE: To describe the type and incidence of race-day veterinary events experienced by Thoroughbred racehorses participating in flat racing in the UK. STUDY DESIGN: Retrospective cohort study (2000 to 2013). METHODS: Veterinary events recorded by race-day veterinarians were retrieved and linked to race start data. Race-day veterinary events were described by type, location and anatomical structure(s) affected and whether the outcome was fatal or not. Incidence per 1000 starts was calculated, both overall and by year. Stratified incidence rates were calculated for selected event categories by specific course- and horse-level variables. RESULTS: There were 7993 events experienced by 6727 horses, with an incidence of 9.37 events per 1000 starts. Soft tissue injuries other than tendon and ligament injuries were the most commonly occurring veterinary events (24.1%), followed by gait observations (21.2%) and respiratory conditions (21.2%). In total, 13.8% of events were bone injuries. The incidence of fatality (n = 628) was 0.76 per 1000 starts. Most (485/628, 77.2%) fatal events were bone injuries, 64 were due to cardiac conditions and 54 due to tendon and ligament injuries. All-weather tracks had a higher incidence of veterinary events and fatalities than turf tracks. Firmer (turf) or faster (all-weather) going were associated with a higher incidence of all veterinary events. MAIN LIMITATIONS: Events were based on presumptive, rather than definitive, veterinary diagnosis. CONCLUSION: The most common events experienced by racehorses on race-day were relatively minor and not career-ending. Although more severe bone, joint, tendon and ligament injuries were less common, they had a greater impact on whether the outcome of the event was fatal.

Digital flexor tendon lacerations in horses: 50 cases (1975-1990).

The medical records of 50 horses examined because of lacerations of the tendon of the superficial or deep digital flexor muscle were reviewed to determine whether any injury or treatment factors could be associated with outcome. Median age of horses treated was 4.5 years (range, 1.5 years to 15 years), and the median follow-up time was 5 years (range, 1.5 to 16 years) after injury. Horses were considered to have survived if they were alive more than 1 year after injury. Twelve of 16 horses that had 1 or the other tendon transected survived; 13 of 16 horses that had both tendons transected survived; and 14 of 18 horses that had partial tendon disruptions of 1 or both tendons survived. Of the 39 surviving horses, 27 horses returned to their original use, and 32 horses were sound for riding. Nine horses with 1 or both tendons transected were being used for athletic activities. Lacerated tendons were sutured in 16 horses, and 15 of these survived. Tendons were not sutured in 34 horses, and 24 of these survived. We were not able to detect any association between outcome and tendon sheath involvement or between outcome and limb involvement (forelimb vs hind limb).