If identification of markers for pre‐fracture change can be detected, using either existing or future imaging modalities, then reliable screening methods for fracture risk can be developed. A key advance will be our ability to correctly identify and select horses for whom such ‘intensive’ screening would be most useful. Identification of a reliable pre‐imaging screening test that effectively rules out a large proportion of horses from being at risk of fracture should therefore be the priority. In other words, a simple, quick and cheap pre‐screening test that has a very high sensitivity (resulting in very few false negatives and a high negative predictive value) is required so that only those horses that are at greatest risk are evaluated. This would effectively increase the prevalence of fracture in the population subjected to the secondary test with resultant improvement in its positive predictive value. A substantial reduction in false positive results increases the reliability of a positive result and thus enhances confidence in making recommendations for future training. Such screening programmes would permit the introduction of interventions, such as alterations to training regimens based on known risk factors that, in turn, should reduce the likelihood of fracture in susceptible horses.
References
1 1 Williams, R.B., Harkins, L.S., Hammond, C.J., and Wood, J.L. (2001). Racehorse injuries, clinical problems and fatalities recorded on British racecourses from flat racing and National Hunt racing during 1996, 1997 and 1998. Equine Vet. J. 33: 478–486.
2 2 McKee, S.L. (1995). An update on racing fatalities in the UK. Equine Vet. Educ. 7: 202–204.
3 3 Allen, S.E., Rosanowski, S.M., Stirk, A.J., and Verheyen, K.L.P. (2017). Description of veterinary events and risk factors for fatality in National Hunt flat racing Thoroughbreds in Great Britain (2000‐2013). Equine Vet. J. 49: 700–705.
4 4 Rosanowski, S.M., Chang, Y.M., Stirk, A.J., and Verheyen, K.L.P. (2017). Descriptive epidemiology of veterinary events in flat racing Thoroughbreds in Great Britain (2000 to 2013). Equine Vet. J. 49: 275–281.
5 5 Rosanowski, S.M., Chang, Y.M., Stirk, A.J., and Verheyen, K.L.P. (2017). Risk factors for race‐day fatality, distal limb fracture and epistaxis in Thoroughbreds racing on all‐weather surfaces in Great Britain (2000 to 2013). Prev. Vet. Med. 148: 58–65.
6 6 Wylie, C.E., McManus, P., McDonald, C. et al. (2017). Thoroughbred fatality and associated jockey fall and injuries in races in New South Wales and the Australian Capital Territory, Australia: 2009–2014. Vet. J. 227: 1–7.
7 7 Maeda, Y., Hanada, M., and Oikawa, M. (2016). Epidemiology of racing injuries in Thoroughbred racehorses with special reference to bone fractures: Japanese experience from the 1980s to 2000s. J. Equine Sci. 27: 81–97.
8 8 McGlinchey, L., Hurley, M.J., Riggs, C.M., and Rosanowski, S.M. (2017). Description of the incidence, clinical presentation and outcome of proximal limb and pelvic fractures in Hong Kong racehorses during 2003–2014. Equine Vet. J. 49: 789–794.
9 9 Vaughan, L.C. and BJE, M. (1976). A Clinico‐Pathological Study of Racing Accidents in Horses. A Report of a Study on Equine Fatal Accidents on Racecourses. London, United Kingdom: Horserace Betting Levy Board.
10 10 Parkin, T.D.H., French, N.P., Riggs, C.M. et al. (2004). Risk of fatal distal limb fractures among Thoroughbreds involved in the five types of racing in the United Kingdom. Vet. Rec. 154: 493–497.
11 11 Johnson, B.J., Stover, S.M., Daft, B.M. et al. (1994). Causes of death in racehorses over a 2 year period. Equine Vet. J. 26: 327–330.
12 12 Boden, L.A., Charles, J.A., Slocombe, R.F. et al. (2005). Sudden death in racing Thoroughbreds in Victoria, Ausralia. Equine Vet. J. 37: 269–271.
13 13 Boden, L.A., Anderson, G.A., Charles, J.A. et al. (2006). Risk of fatality and causes of death of Thoroughbred horses associated with racing in Victoria, Australia: 1989–2004. Equine Vet. J. 38: 312–318.
14 14 Reardon, R.J.M., Boden, L.A., Stirk, A.J., and Parkin, T.D.H. (2014). Accuracy of distal limb fracture diagnosis at British racecourses 1999–2005. Vet. Rec. 174: 477.
15 15 Hill, T., Carmichael, D., Maylin, G. et al. (1986). Track condition and racing injuries in Thoroughbred horses. Cornell Vet. J. 76: 361–379.
16 16 Peloso, J.G., Mundy, G.D., and Cohen, N.D. (1994). Prevalence of and factors associated with musculoskeletal racing injuries of Thoroughbreds. J. Am. Vet. Med. Assoc. 204: 620–626.
17 17 Estberg, L., Stover, S.M., Gardner, I.A. et al. (1996). Fatal musculoskeletal injuries incurred during racing and training in Thoroughbreds. J. Am. Vet. Med. Assoc. 208: 92–96.
18 18 Estberg, L., Stover, S.M., Gardner, I.A. et al. (1998). Relationship between race start characteristics and risk of catastrophic injury in Thoroughbreds: 78 cases (1992). J. Am. Vet. Med. Assoc. 212: 544–549.
19 19 Georgopoulos, S.P. and Parkin, T.D.H. (2017). Risk factors for equine fractures in Thoroughbred flat racing in North America. Prev. Vet. Med. 139: 99–104.
20 20 The Jockey Club News Release March 19th 2018 http://www.jockeyclub.com/Default.asp?section=Resources&area=10&story=1039 (accessed 26 September 2018).
21 21 Sarrafian, T.L., Case, J.T., Kinde, H. et al. (2012). Fatal musculoskeletal injuries of Quarter Horse racehorses: 314 cases (1990–2007). J. Am. Vet. Med. Assoc. 241: 935–942.
22 22 Stover, S.M. and Murray, A. (2008). The California postmortem program: leading the way. Vet. Clin. Equine 24: 21–36.
23 23 Collar, E.M., Zavodovskaya, R., Spriet, M. et al. (2015). Caudal lumbar vertebral fractures in California Quarter Horse and Thoroughbred racehorses. Equine Vet. J. 47: 573–579.
24 24 Misheff, M.M., Alexander, G.R., and Hirst, G.R. (2010). Management of fractures in endurance horses. Equine Vet. Educ. 22: 623–630.
25 25 Singer, E.R., Barnes, J., Saxby, F., and Murray, J.K. (2008). Injuries in the event horse: training versus competition. Vet. J. 175: 76–81.
26 26 Caston, S.S. and Burzette, R.G. (2018). Demographics, training practices, and injuries in lower level event horses in the United States. J. Equine Vet. Sci. 62: 25–31.
27 27 Verheyen, K.L.P. and Wood, J.L.N. (2004). Descriptive epidemiology of fractures occurring in British Thoroughbred racehorses in training. Equine Vet. J. 36: 167–173.
28 28 Verheyen, K.L., Newton, J.R., Price, J.S., and Wood, J.L. (2006). A case‐control study of factors associated with pelvic and tibial stress fractures in Thoroughbred racehorses in training in the UK. Prev. Vet. Med. 74: 21–35.
29 29 Ely, E.R., Avella, C.S., Price, J.S. et al. (2009). Descriptive epidemiology of fracture, tendon and suspensory ligament injuries in National Hunt racehorses in training. Equine Vet. J. 41: 372–378.
30 30 Perkins, N.R., Reid, S.W.J., and Morris, R.S. (2005). Profiling the New Zealand Thoroughbred racing industry. 2. Conditions interfering with training and racing. N. Z. Vet. J. 53: 69–76.
31 31 Dyson, P.K., Jackson, B.F., Pfeiffer, D.U., and Price, J.S. (2008). Days lost from training by two‐ and three‐year‐old Thoroughbred horses: a survey of seven UK training yards. Equine Vet. J. 40: 650–657.
32 32 Ramzan, P.H.L. and Palmer, L. (2011). Musculoskeletal injuries in Thoroughbred racehorses: a study of three large training yards in Newmarket, UK (2005–2007). Vet. J. 187: 325–329.
33 33 Egenvall, A., Tranquille, C.A., Lonnell, A.C. et al. (2013). Days‐lost to training and competition in relation to workload in 263 elite show‐jumping horses in four European countries. Prev. Vet. Med. 112: 387–400.
34 34 Schneider, R.K., Bramlage, L.R., Gabel, A.A. et