Factors associated with failure of thoroughbred horses to train and race.
BACKGROUND
The low productivity associated with training and racing of young Thoroughbreds (TBs) in the UK due to athletic inability, injury and disease requires further study.


OBJECTIVE
To identify the time points and causes of losses during growth and training phases of a cohort of 1022 TB foals born in 1999 up to the end of their third year.


METHODS
Movement and fate of 1022 Thoroughbred foals conceived in 1998 and born live in 1999 were monitored from birth to age 3 years. Those (n = 562) that entered training age 2 and/or 3 years with one of 161 registered trainers in Britain or Ireland in 2001/2 were analysed as to their subsequent performance and the incidence of 9 common injuries or infective or metabolic illnesses.


RESULTS
Of the 1022 foals identified, 537 (52%) entered training at age 2 years, 289 (28%) were exported, 60 (6%) were kept as 'stores' for National Hunt (NH) racing, 58 (6%) died or were destroyed, 25 (2%) were waiting to enter training at age 3 years, 17 (2%) were never intended for racing and 36 (4%) were untraceable. Race records showed that 327 (61%) of the 2-year-olds in training competed one or more times, 95 (18%) won and 165 (31%) were placed. Only 28 (5%) earned enough prize money to cover their training fees. Sore shins and inflammatory airway disease (IAD) were the 2 ailments most commonly encountered. In 2002, 431 (80%) of the previous year's 2-year-olds remained in training aged 3 years and 25 entered training having not raced previously. Of the 456 3-year-olds in training, 347 (76%) raced one or more times 138 (30%) won, 218 (48%) were placed and 78 (17%) recouped their training fees. Joint problems and sore shins were the ailments most commonly suffered and, with the exception of rhabdomyolysis ('tying up'), colts and geldings suffered a higher rate of muscloskeletal injuries than fillies.


CONCLUSIONS
Previous reports of high nonrun and nonplaced rates, high incidence of injury and cost-ineffectiveness of 2-year-olds in flat-race training were confirmed.


CONCLUSIONS
This study lays the basis for further studies of the facets involved in wastage.
Wilsher
S
S
Department of Veterinary Medicine, University of Cambridge, Cambridge, UK.
Allen
W R
WR
Wood
J L N
JL
D000367:Age Factors; D000818:Animals; D015331:Cohort Studies; D005260:Female; D006734:Horse Diseases / Q000191:economics / Q000453:epidemiology*; D006736:Horses / Q000293:injuries / Q000502:physiology*; D007794:Lameness, Animal / Q000191:economics / Q000453:epidemiology; D008297:Male; D009140:Musculoskeletal Diseases / Q000191:economics / Q000453:epidemiology / Q000662:veterinary*; D010805:Physical Conditioning, Animal / Q000009:adverse effects / Q000191:economics; D012140:Respiratory Tract Diseases / Q000191:economics / Q000453:epidemiology / Q000662:veterinary*; D012737:Sex Factors; D013177:Sports; D014947:Wounds and Injuries / Q000191:economics / Q000453:epidemiology / Q000662:veterinary*