[Ultrasonographic examination of the musculoskeletal system in cattle]

Ultrasound machines with 7.5 to 5.0MHz linear transducers are well suited for rapid and straightforward differentiation of soft tissue swelling in the musculoskeletal system of cattle; in proximal limb regions 3.5MHz convex scanners allow better imaging. The main indications for ultrasonography of the musculoskeletal system in cattle are suspected arthritis, tenosynovitis, bursitis, abscesses, haematomas, diagnosis of muscle and tendon lesions, and generally the evaluation of soft tissue swellings everywhere that cannot be diagnosed based on clinical examination. The examiner starts by obtaining a general overview of the affected region for orientation purposes. This is achieved by locating and identifying anatomical landmarks, thereafter one can search for pathological changes by examination of the region of interest in longitudinal and transverse planes from all sides. The ultrasonographic investigation should follow a standardised systematic protocol. Normal synovial cavities in cattle are difficult or impossible to visualize via ultrasonography because of the very small physiological amount of synovial fluid. Thus, effusion that is easily visualized usually indicates a pathological process like arthritis, tenosynovitis or bursitis. Ultrasonography provides accurate information about the location and size of lesions or fluid-filled cavities, the nature of the content and an exact measurement of the distance from pathologically altered structures to the skin surface. Targeted centesis of synovial or other cavities can be carried out after a preliminary ultrasonographic inspection. Characterization of the lesions and a thorough preoperative inspection of affected regions are of enormous benefit for planning surgery and treatment.