A vet can see various structures and conditions on an ultrasound, including:

1. Organs: The size, shape, and position of organs like the liver, kidneys, bladder, spleen, pancreas, and heart.
2. Fluid Accumulation: Detecting abnormal fluid in the abdomen or chest, which can indicate issues like infections, tumors, or organ failure.
3. Pregnancy: Confirming pregnancy and assessing the health and number of fetuses.
4. Tumors: Identifying masses or abnormal growths in organs or tissues.
5. Blood Flow: Using Doppler ultrasound to evaluate blood flow in vessels and check for issues like blood clots or heart problems.
6. Gastrointestinal Issues: Examining the stomach and intestines for blockages, inflammation, or other gastrointestinal disorders.

Ultrasound is a valuable non-invasive tool for diagnosing various conditions in pets.