Ultrasonographic assessment of the superficial digital flexor tendons of National Hunt racehorses in training over two racing seasons
Article first published online: 5 JAN 2010
2009 EVJ Ltd
Equine Veterinary Journal
Volume 41, Issue 5, pages 449–454, May 2009
How to Cite
AVELLA, C. S., ELY, E. R., VERHEYEN, K. L. P., PRICE, J. S., WOOD, J. L. N. and SMITH, R. K. W. (2009), Ultrasonographic assessment of the superficial digital flexor tendons of National Hunt racehorses in training over two racing seasons. Equine Veterinary Journal, 41: 449–454. doi: 10.2746/042516409X391042
- Issue published online: 5 JAN 2010
- Article first published online: 5 JAN 2010
- [Paper received for publication 10.07.08; Accepted 03.11.08]
- superficial digital flexor tendon;
- cross-sectional area;
Reasons for performing study: It is important to ascertain the prevalence of superficial digital flexor tendon (SDFT) injuries and to improve methods of predicting injury in National Hunt (NH) racehorses.
Objectives: To establish: 1) the prevalence of SDFT tendinopathy in NH horses; 2) whether routine ultrasonography can be used to predict SDFT injuries; 3) whether previous tendinopathy predisposes to reinjury; 4) a normal range for the SDFT cross-sectional area (CSA); and 5) the effects of gender, age, background (ex-flat or exstore), limb, training and rest periods on SDFT CSA.
Methods: Routine ultrasound assessment of the palmar metacarpal soft tissues of 263 NH racehorses was performed on up to 6 occasions over 2 NH racing seasons.
Results: The prevalence of SDFT pathology detected using ultrasonography was 24% (n = 148), with a nonsignificant variation between yards of 10–40%. No changes in SDFT CSA or ultrasonographic appearance were detected prior to injury. Older horses had a significantly higher prevalence of SDFT pathology compared to younger horses, and horses with tendinopathy were more likely to suffer an acute injury compared to horses with no evidence of pathology. A reference range for normal CSA measurements was established as 77–139 mm2 at level 4, from 142 horses with no ultrasonographic evidence of SDFT pathology. The CSA of normal horses did not vary significantly with age, limb or over 2 racing seasons, but did with sex and background.
Conclusions: The study confirms that SDFT tendinopathy is common in NH horses, with substantial variation between training yards. Ultrasonography at 3 month intervals did not seem to predict acute SDFT injuries.
Potential relevance: Variation in the prevalence of tendinopathy between yards suggests that training methods may influence injury rate. It was not possible to predict injury using routine ultrasonography and therefore other methods must be identified. A normal reference range for SDFT CSA is provided.