General information regarding Standardbred trotters in training in 57 yards in Sweden and additional information regarding each case and control horse in 22 yards participating in case control study.

*Obtained from www.travsport.se (Swedish Trotting Association website) up to and including the end of 2007. The “points” statistic is derived from performance in the last 5 starts, where 1st place gives 200, 2nd gives 100, 3rd gives 65, 4th gives 25 and 5th gives 15 points. In addition each horse is awarded 1 point for each 100 SEK earned.