The failure to excrete [[Bilirubin|bilirubin]] results in an increase in the blood concentration of conjugated bilirubin. Beyond a certain level, this bilirubin stains tissues causing [[Icterus|jaundice]] which may be visible on the mucous membranes or sclera. Since bilirubin has a low renal threshold, high concentrations are found in urine, although bilirubinuria is not necessarily an abnormal finding in healthy animals. In a complete biliary obstruction, [[Bilirubin|urobilinogen]] will also be absent from the urine. | The failure to excrete [[Bilirubin|bilirubin]] results in an increase in the blood concentration of conjugated bilirubin. Beyond a certain level, this bilirubin stains tissues causing [[Icterus|jaundice]] which may be visible on the mucous membranes or sclera. Since bilirubin has a low renal threshold, high concentrations are found in urine, although bilirubinuria is not necessarily an abnormal finding in healthy animals. In a complete biliary obstruction, [[Bilirubin|urobilinogen]] will also be absent from the urine. |