Overview: The whites of the eyes of a cat with jaundice often are more yellow than they are white; the animal's skin and gums may develop a yellowish tinge as well. These changes in color result from deposits of bile pigment entering the cat's tissues, a common occurrence among animals with jaundice. Unfortunately, this yellowish hue is not as serious as the possible diseases that can be associated with it, including kidney damage, liver disease, and disorders of the nervous system.
Clinically known as icterus, jaundice occurs when the cat's body has too much of a substance called bilirubin, which comes from red blood cells that have been processed by the spleen, the liver, and by bone marrow. In a normal cat, the liver will absorb, metabolize, and excrete this bilirubin. Jaundice results when too much bilirubin is being produced, when the liver is not able to adequately process the bilirubin, or when the bilirubin cannot be excreted.
Jaundice is not a disease but a symptom caused by a wide range of feline diseases that result in too much bilirubin being present in the body. Some of these diseases can be fatal. When the underlying illness is severe and irreversible, neither it nor the jaundice can be treated.
Description: Cats that have jaundice develop a yellowish color to their skin, gums, and the whites of their eyes because of deposits of bile pigment in their body tissues. Jaundice occurs when the body has too much of a substance called bilirubin, which comes from red blood cells that have been processed by the spleen, the liver, and by bone marrow. In a normal cat, the liver will absorb, metabolize, and excrete this bilirubin through the bile duct system. Problems occur and jaundice results when too much bilirubin is being produced, when the liver is not able to adequately process the bilirubin, or when excretion of the bilirubin is prohibited.
Jaundice, which is not a disease but a symptom of many different diseases, can make already existing liver disease worse. It can result in an obstruction to the flow of bile, in kidney damage, and even in comas and disorders of the nervous system. Many cats will require hospitalization during diagnosis and treatment. Following hospitalization, the owner may need to provide intensive at-home nursing care.
Depending on the cause of the jaundice and the severity of the illness, the liver may be able to repair itself. Some cats, however, will never recover from the disease that causes the jaundice.
Diagnosis: Diagnosis is focused on finding the reason why the cat has an excessive amount of bilirubin, or "hyperbilirubinemia," that is causing the jaundice. The veterinarian will take a careful medical history about the animal, perform a complete medical examination, and conduct appropriate diagnostic tests. Routine laboratory testing will include a complete blood cell count, or CBC, a serum chemistry panel, and urinalysis.
Additional testing needed may include abdominal and chest x-rays, a blood coagulation profile, a test for blood parasites, a serum bile acids test, an infectious disease serology, an abdominal ultrasound, and an abdominal exploratory exam. Liver biopsies, taken by ultrasound or surgery, are commonly needed in cases of liver disease. The veterinarian will recommend the appropriate diagnostic procedures based on a cat's individual case and its response to therapy. Some complicated cases are referred to veterinary internal medicine specialists.
Transmission or Cause: Jaundice results when there is too much bilirubin in the body. There are several reasons why a cat may have excessive bilirubin, a condition that the veterinarian may refer to as hyperbilirubinemia. One cause is pre-hepatic icterus, in which there is so much bilirubin being produced that the liver is unable to process all of it. Pre-hepatic icterus often results from a breakdown of red blood cells due to the feline leukemia virus infection, defects in the blood clotting mechanism, and certain medications.
When a cat has an abnormal metabolism and excretion of bilirubin by its liver cells, it has the primary hepatic form of jaundice. Primary hepatic jaundice is the most common cause of icterus in the cat. Liver diseases that can affect cats include acute toxic hepatitis, cholangiohepatitis, cirrhosis of the liver, and feline fatty liver syndrome. Other diseases that result in damage to the liver -- such as diabetes mellitus, the feline infectious peritonitis virus, cancer, and the feline leukemia virus -- can also cause primary hepatic jaundice.
Finally, when the cat's bile duct system interferes with the excretion of bilirubin, a type of jaundice called post-hepatic icterus results. Causes of this include bile duct obstruction, a rupturing of the bile duct, pancreatitic disease, cancer, inflammation of the gallbladder, and inflammation of a bile duct.
Treatment: There are various treatments for jaundice, all of which depend on the symptoms and the cause. Some diseases that cause jaundice, such as inoperable cancer, are irreversible and result in death. However, other diseases, such as feline fatty liver syndrome, in which fat gets deposited into the liver tissue, can be managed quite effectively. Cats with life-threatening anemia will need a blood transfusion.
Most animals with jaundice will require hospitalization initially. Intravenous fluid administration, cage rest to encourage the liver to heal, and appropriate nutritional support may be needed. The veterinarian will prescribe medications to manage symptoms such as vomiting, nausea, excessive abdominal fluid, and neurological problems; these medications must be carefully monitored, however, since the liver metabolizes many drugs. Follow-up visits with blood and urine re-evaluations will be needed to determine the success of the treatment.