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TREADMILL TESTING
IGH-speed treadmills have been used for performance testing horses for the past two decades and as a result can be found around the world in many of the major equine hospitals. The introduction of the equine high-speed treadmill brought about the possibility of using traditional veterinary tools, such as the flexible endoscope and the electrocardiograph (ECG), to examine horses whilst exercising at near-racing speed. This, combined with the control and repeatability of the treadmill test, made the equine high-speed treadmill an excellent research and diagnostic tool and resulted in incredible advances in veterinary medicine. However, technology does not stand still and the introduction of the portable ECG machine nearly five years ago has recently been followed up with the advent of the over -ground endoscope. These advances are now challenging the high-speed treadmill and its position as the gold standard for the dynamic diagnosis of equine respiratory and cardiovascular problems. Could this mark the end of high-speed treadmill testing?
“Reports of horse and operator injury during treadmill testing have simply served to make owners and trainers more cautious to use them”
Horses are introduced to a treadmill gradually and the time taken for a horse to become comfortable enough with the treadmill to exercise freely at high speeds varies between individuals. Testing is often carried out on the third day after the introduction of a horse to a treadmill for the first time. Perhaps one of the main advantages of high-speed treadmill exercise is that it provides a controlled and repeatable test. Veterinarians are able to accurately measure how hard a particular horse is being pushed. The speed and incline of the treadmill is both recordable and repeatable and unlike turf, dirt or synthetic tracks, the surface on which the horse exercises does not vary at all either with the weather or different sections of the track. As horses are going ‘nowhere fast’ on the treadmill, it is possible to assemble a wide range of recording equipment close by and this produces the opportunity to record a variety of data simultaneously in order to achieve a comprehensive assessment of a horse’s athletic ability and identify any abnormalities. The control and repeatability of treadmill testing combined with the ease with which equipment can be gathered around a fastmoving horse has made it an excellent tool with which to conduct research. During the last two decades, research has been carried out on high-speed treadmills into several body systems of the horse. For example,
Gleadhill et al. analyzed kidney function during exercise back in 2000 and found that the Thoroughbred is able to dramatically reduce its kidney function to allow itself to exercise to a high level. In 2001 Geor et al. used a treadmill to study the effects of Lasix® and nasal strips on bleeding and in 2002 Nyman et al. used a treadmill to study water intake and fluid shifts in horses at exercise. The equine gait has also been studied in detail on high-speed treadmills and work has been carried out into the effects of variables such as lameness and shoeing/trimming. Butcher et al. used a treadmill in 2007 to study digital flexor tendons in motion and they produced a theory as to why such injuries might occur – essentially that the deep digital flexor tendon becomes fatigued first leading to overloading of the superficial flexor tendon and the potential for injury. The controlled environment in which treadmill testing takes place has made them excellent for many ‘fair’ tests and one excellent example is ‘head-shaking.’ This condition can be investigated whilst lunging or exercising outside, but several veterinary centers have used treadmills for the testing of ‘head-shakers’ to see what stimulates each individual. As the external environment remains completely consistent (the treadmill room remains the same), various stimuli, for example, light or noise, can be tested to see their effect on the individual horse. However, although the treadmill has been used as a tool ISSUE 11 TRAINERMAGAZINE.com 57