Objective—To determine the association between
high-speed exercise and risk of injury while racing
among Thoroughbreds in Kentucky.
Design—Matched case-control study.
Animals—206 Thoroughbreds that sustained a musculoskeletal
injury while racing and 412
Thoroughbreds that were not injured during the same
Procedure—Data regarding official timed workouts
and races and the Beyer's numbers for the 3 races
before the race during which injury occurred were
extracted from past performance charts and compared
between injured horses and control horses.
Results—For injured horses, cumulative distance of
high-speed exercise during the 1- and 2-month periods
prior to the race in which injury occurred was significantly
less than that of control horses; for either
period, a difference of 10 furlongs was associated
with approximately 2-fold greater risk of injury.
Beyer's numbers were significantly higher for injured
horses than for control horses. These effects
remained significant after adjusting for age and
results of prerace physical inspection.
Conclusions and Clinical Relevance—In Kentucky,
injured horses had significantly less cumulative highspeed
exercise than did control horses during the 1-
and 2-month periods prior to the race in which injury
occurred. These results differ from those observed in
California. The association of injury with cumulative
high-speed exercise appears to vary among regions in
the United States. (J Am Vet Med Assoc 2000;
Objective—To determine whether mares are a clinically important source of Rhodococcus equi for their foals.
Sample Population—171 mares and 171 foals from a farm in Kentucky (evaluated during 2004 and 2005).
Procedures—At 4 time points (2 before and 2 after parturition), the total concentration of R equi and concentration of virulent R equi were determined in fecal specimens from mares by use of quantitative bacteriologic culture and a colony immunoblot technique, respectively. These concentrations for mares of foals that developed R equi–associated pneumonia and for mares with unaffected foals were compared. Data for each year were analyzed separately.
Results—R equi–associated pneumonia developed in 53 of 171 (31%) foals. Fecal shedding of virulent R equi was detected in at least 1 time point for every mare; bacteriologic culture results were positive for 62 of 171 (36%) mares at all time points. However, compared with dams of unaffected foals, fecal concentrations of total or virulent R equi in dams of foals with R equi–associated pneumonia were not significantly different.
Conclusions and Clinical Relevance—Results indicate that dams of foals with R equi–associated pneumonia did not shed more R equi in feces than dams of unaffected foals; therefore, R equi infection in foals was not associated with comparatively greater fecal shedding by their dams. However, detection of virulent R equi in the feces of all mares during at least 1 time point suggests that mares can be an important source of R equi for the surrounding environment.