Evaluation of poor performance in competition horses: A musculoskeletal perspective. Part 2: Further investigation

There is not a right and a wrong way of investigating musculoskeletal causes of poor performance in sports horses and the methods of investigation are, in part, determined by the clinical signs. Measurement of serum muscle enzyme concentrations before and after exercise is essential for recognition of primary muscle pathology. Many horses with multilimb lameness have a secondary reduced range of motion of the thoracolumbosacral region mimicking primary thoracolumbar pain. Radiographic examination of the thoracolumbar vertebrae may be confusing unless combined with diagnostic analgesia because many clinically normal horses have radiological abnormalities. Nuclear scintigraphy offers a method of evaluating a large proportion of the horse, but there are many false positive and false negative results. Diagnostic analgesia is the most reliable method of investigation but requires experience and skill in interpretation and is time consuming in a horse with multilimb lameness.