RELATIONSHIP BETWEEN RACE START CHARACTERISTICS AND RISK OF CATASTROPHIC INJURY IN THOROUGHBREDS - 78 CASES (1992)

Objective-To investigate relationships of several racehorse characteri stics and race conditions with risk of a catastrophic musculoskeletal injury (CMI) resulting in euthanasia in Thoroughbreds during racing in California in 1992. Design-Retrospective longitudinal study. Animals- Thoroughbreds that incurred CMI during racing and all California race entrants in 1992. Procedure-Necropsy records were reviewed, and race s tart information was obtained. incidence risk of CMI/1,000 race entran ts was estimated. Relationships between CMI during racing and race-mee t, entrant age and sex, race type and length, and racing surface type and condition were evaluated by use of logistic regression. Results-In cidence risk of CMI was 1.7/1,000 entrants. A higher risk of CMI was f ound at 2 fair race-meets, with incidence risks of 4.9 and 5.5/1,000 e ntrants. Risk of injury in male horses was 1.7 times greater than that in female horses, and influence of age on risk depended on race type. Risk of injury for horses 2 to 5 years old was two times greater for claiming horses than For maiden horses. Race length or racing surface type (dirt vs turf) or condition (fast, muddy, yielding) were not sign ificantly associated with risk of CMI. Clinical Implications-Incidence of CMI was similar among 12 of 14 major and fair race-meets and among various race lengths and racing surface types and conditions, whereas incidence of CMI was influenced by entrant age and sex as well as rac e type. Investigators should consider controlling for age and sex, rac e-meet, and race type whenever possible in studies of risk of CMI.