The movement pattern of horses around race meetings in New Zealand

Abstract

In order to describe the implications of racehorse movement on the potential spread and control of infectious disease in New Zealand, the movement of horses due to regular racing activities needed to be quantified. Race meeting, trainer and starter data were collected in 2009 from the governing bodies for the two racing codes in New Zealand; Harness Racing New Zealand and New Zealand Thoroughbred Racing. During 2009, 507 Thoroughbred and 506 Standardbred race meetings were held. A random selection of 42 Standardbred and 39 Thoroughbred race meetings were taken from all race meetings held in 2009 and the distances travelled by trainers to these race meetings were determined. The trainers attending selected race meetings represented 50% (1135/2287) of all registered trainers in 2009. There was no seasonal pattern of when race meetings were held between racing codes (P = 0.18) or by race type (P = 0.83). There were significant differences in the distance travelled by trainers to race meetings, by racing code (P < 0.001). Thoroughbred trainers travelled a median of 91 km (IQR 40–203 km), while Standardbred trainers travelled a median of 45 km (IQR 24–113 km) (P < 0.001). Within each racing code, trainers travelled further to attend premier races than other types of race meetings (P < 0.001). These data demonstrate there is higher potential for more widespread disease dissemination from premier race meetings compared with other types of race meetings. Additionally, lack of a seasonal pattern indicates that a widespread outbreak could occur at any time of the year. Widespread disease dissemination would increase the logistic effort required for effective infectious disease control and has the potential to increase the time required to achieve control.