Icterus / jaundiceIcterus / jaundice, also known as jaundice, is the yellowing of the skin, mucous membranes, and whites of the eyes. It is a symptom of elevated bilirubin levels in the blood, which may indicate liver disease or biliary tract problems in dogs and cats., also known as jaundice, is the yellowing of the skin, mucous membranes, and whites of the eyes. It is a symptom of elevated bilirubinBilirubin is a yellow pigment that is produced when hemoglobin from red blood cells is broken down. It is further processed in the liver and then excreted via the bile. Elevated bilirubin levels may indicate liver dysfunction or impaired bile excretion. levels in the blood, which may indicate liver disease or biliary tract problems in dogs and cats.