Race-start characteristics and risk of catastrophic musculoskeletal injury in Thoroughbred racehorses.

OBJECTIVE

To identify race-start characteristics associated with catastrophic musculoskeletal (MS) injury in Thoroughbred racehorses at 2 racetracks in Florida during 1995 through 1998.

DESIGN

Matched case-control study.

ANIMALS

97 Thoroughbreds (case horses) that incurred a catastrophic MS injury during racing and 388 Thoroughbreds (control horses) randomly selected from noninjured participants and matched on the basis of racetrack and year.

PROCEDURE

Incidence of MS injury was calculated for all race meets at 2 racetracks in Florida from 1995 through 1998. Race-start characteristics were compared among case and control horses, using conditional logistic regression.

RESULTS

Overall incidence of MS injury was 1.2/1,000 race starts (97/79,416 starts). Incidence of injury was significantly higher for turf races (2.3/1,000 starts) than for dirt races (0.9/1,000 starts). Sex, number of days since last race, and racing surface were associated with risk of injury; geldings, > or = 33 days since the last race, and turf racing surface were associated with a higher risk of injury.

CONCLUSIONS AND CLINICAL RELEVANCE

Incidence of injury among Thoroughbreds in Florida was associated with sex, number of days since last race, and racing surface. Days since last race may have been an indicator of previous health and lameness problems. Racing surface may have been a risk factor for MS injury because turf races tended to be more competitive than dirt races. Horses running in turf races were more likely to participate in races with a large field, handicap races, long races, and races with high purses.