Characteristics of Endurance Competitions and Risk Factors for Elimination in New Zealand during Six Seasons of Competition (2010/11-2015/16).

The welfare of horses in endurance competitions has been the focus of recent media attention. Epidemiological studies have examined the sport at the international (FEI) level. However, much of the participation in the sport occurs at a national level in preparation for FEI level competition. The aims of this study were to describe participation in, and risk factors for elimination, from New Zealand endurance competitions. Data were collated from all endurance competitions (≥40 km) held in New Zealand during the 2010/11-2015/16 competition seasons. There were 6885 starts (n = 775 horses, n = 665 riders), horses had a median age of 9 years (IQR 6.2-10.0) and had a median of 3 (IQR 2-5) starts per season. Accumulated ride distance per season per horse decreased from a median of 240 km/horse (IQR 120-440) in 2010/11 to 180 km/horse (IQR 80-320) in 2015/16. Ride entries were dominated by the 40 km (n = 2834, 41%) and 80 km (n = 2517, 37%) distances. Eliminations increased with ride distance, from 7% in 40 km rides to 53% in the 160 km rides. Lameness accounted for the majority of eliminations (64%). The odds of elimination due to lameness were significantly associated with ride distance, location (North or South island) and time of year. The 11% of starters eliminated for metabolic reasons of the horse had increased odds of elimination associated with horse age, ride distance, location and time of year.