Clinical evaluation of poor performance in the racehorse: the results of 275 evaluations.

The research studies the underlying causes of poor racing performance in 275 racehorses using a comprehensive clinical sports medicine evaluation. The results show that 84% of these horses had multiple health issues, and diagnosis often required specialized equipment and a tailored approach.

Methodology

• A detailed clinical sports medicine evaluation was performed on 275 racehorses showing poor racing performance.
• The evaluation included a general physical and basic laboratory screening for initial health assessment.
• An examination of the respiratory system was conducted including auscultation, thoracic x-rays, lung scintigraphy (a diagnostic test which uses radioactive material to examine your lungs), and upper airway endoscopy at rest and during maximal treadmill exercise.
• The horses also underwent a thorough examination of their musculoskeletal system which included lameness check, high-speed video gait analysis, post-exercise blood chemistry for detecting myopathies (diseases of the muscle tissue), high detail radiography, and nuclear scintigraphy (a special imaging technique used to visualize bone disorders).
• A cardiac examination was performed involving auscultation, electrocardiographic analysis during intense exercise, and echocardiography when needed.
• A standardized exercise stress test was conducted measuring oxygen consumption, carbon dioxide production, venous blood lactate levels and heart rate during progressively increasing running speeds on a high-speed treadmill.
• The choice of diagnostic approaches was carefully selected for each horse to most efficiently determine the abnormalities contributing to inadequate racing performance.

Findings

• The results of these extensive clinical evaluations revealed that many of the diagnoses were subtle and not easily detectable, requiring the use of sophisticated diagnostic equipment such as scintigraphy and high-speed treadmill exercise assessments.
• It was surprising to find that 84 per cent of the horses were diagnosed as suffering from more than one medical condition.
• The high prevalence of multi-morbidity led to the authors’ supposition that inadequate athletic performance could often be attributed to a combination of various abnormalities, highlighting the need for a comprehensive diagnostic approach to effectively address reduced athletic capability in racehorses.