Ultrasound is a powerful diagnostic tool that creates a real-time image of an animal’s body. It works by broadcasting high-frequency sound waves that reflect off your pet’s internal structures. A small probe held against the skin collects the returning signals to create an image of the internal body, most commonly used to examine the abdominal organs like the pancreas, stomach, kidneys, adrenal glands, liver, gallbladder, spleen, and lymph nodes. Ultrasound is also used to evaluate regions of the thorax, including the lungs and lymph node, as well as glands in the neck, such as the thyroid gland.