Umbilical masses in calves are commonly encountered by bovine practitioners. They may vary in size from a small, discrete swelling to an extremely large mass. A mass at the umbilicus represents one of two basic situations: herniation or inflammation. A simple hernia is characterized by its reducibility, lack of pain on palpation, and the presence of a hernial ring. Inflammation (or infection) may be localized to the umbilical opening alone, or extend to involve intra-abdominal umbilical cord remnants. Both hernial and inflammatory components can be present in a single umbilical mass. In these cases the mass may be partially reducible, but will also have a component which is non-reducible. Unlike pigs, calves rarely incarcerate their hernias unless a significant inflammatory component is already present; therefore, any mass which is not completely reducible should be considered to have an inflammatory component.