The prinicple of an ultrasonographic examination is equivalent to the system used by bats for orientation at night or the sonar used to measure the depth in submarine navigation. In human and veterinary medicine, ultrasound is used for orientation in the body. Structures located deep in the body become visible and pathologic changes like inflammations, abscesses, tumors, stones (e. g. in the urinary bladder) and foreign bodies in the intestinal tract can be localized.
Especially in horses, ultrasonographic evaluation of the musculoskeletal system can be an important part of the lameness examination. Subsequent healing can be monitored as well, so the attending veterinarian can adjust the training schedule individually.