Understanding abdominal ultrasonography in horses: which way is up?

The recent introduction of more affordable and portable ultrasound equipment makes it possible to perform transabdominal ultrasonography on equine patients in the field. Clipping the hair is not always necessary: intraabdominal structures can be quickly evaluated by soaking hair with isopropyl alcohol and using a 3.0- to 3.5-MHz curvilinear transducer. The ultrasonographer must be acquainted with the location and architecture of normal intraabdominal structures and simultaneously mindful of the depth of the viewing field, the tissue interface densities, the orientation of the transducer relative to the patient, and the image projected on the monitor. A clinician's working knowledge of these elements is the key to building confidence in distinguishing normal from abnormal ultrasonographic findings.