If you notice that the whites of your cat’s eyes appear yellow (jaundiced), she may be suffering from liver disease even if she isn’t acting sick. This is not the time to guess. It’s time to get your cat into the veterinarian.
Jaundice, a yellowing of the mucous membranes of the eyes and mouth and of the skin, is a common sign of liver disease. Jaundice is due to the accumulation of bilirubin, a breakdown product of red blood cells (RBC) that is normally removed from the blood by the liver.
Liver disease is common in cats, and since the liver performs many vital functions, including the production of a wide variety of essential proteins, regulation of metabolism, digestion of food, and detoxification of the blood, cats with liver disease may show a variety of clinical signs.
Causes of Liver Disease
Liver disease can be a primary disorder, meaning there is a disease process within the liver itself. It can also occur secondary to other diseases. A classic example of secondary liver disease in cats occurs with hyperthyroidism.
Many cats, when first diagnosed with hyperthyroidism, have concurrent elevation of liver enzymes on their blood panel. Correction of the primary thyroid disease typically results in full resolution of the liver derangements. Extrahepatic (meaning outside the liver) tumors or even pancreatic swelling that obstructs the flow of bile through the gall bladder and into the intestine are examples of diseases that can cause secondary liver disease in cats.
Several things can cause primary liver disease. “Cholangiohepatitis is the most common primary liver disease I see in my patients,” says Dr. Andrea Lee, Cornell University graduate veterinarian and small animal practitioner in upstate New York. Cholangiohepatitis is characterized by inflammation of the liver and/or bile ducts and can be caused by bacterial, viral, or fungal infections, parasites, immune-mediated disease, and infiltrative cancers like lymphoma or mast cell cancer.
“The next most common liver disease I see in cats is hepatic lipidosis, which is where the liver becomes overwhelmed by fat infiltration. This happens in overweight cats that become anorexic and lose weight rapidly for whatever reason. Assisted feeding via feeding tube is of utmost importance for these cats, to reverse the negative calorie balance that results in fat mobilization to the liver,” says Dr. Lee.
The Importance of Bloodwork
After physically examining your cat carefully, your veterinarian will usually try to determine if the jaundice (or icterus), is due to primary liver disease or to hemolytic anemia using bloodwork. If it’s determined to be due to liver disease, the diagnostic process starts with more bloodwork (chemistry screen, complete blood count [CBC], urinalysis, and T4 thyroid hormone).
Cats with liver disease typically have elevated liver enzymes (ALT, AST, Alk Phos, GGT) and bilirubin on the chemistry panel. Liver function tests like bile acid assays may also be recommended.
With advanced liver disease, blood albumin and cholesterol concentrations may be low, as these are produced by the liver. The CBC may show elevation of white blood cells due to inflammation or infection, and this test may also identify a decreased RBC (anemia) secondary to inappropriate RBC destruction (as is seen with hemolytic anemia).
Blood T4 testing is especially important in senior cats, as hyperthyroidism is common in geriatric felines. Urinalysis is also important, as liver disease can create urinary crystals that may form into bladder stones.
Imaging
The next diagnostic step usually involves imaging. This can be done with abdominal X-rays and/or ultrasound. Ultrasound tends to be higher yield for liver cases, as it gives the radiologist a dynamic three-dimensional view of everything in the abdomen. Ultrasound is also a better way to image the pancreas and intestines, an important aspect of ruling out a condition called triaditis, in which the liver, pancreas, and small bowel are inflamed. CT or MRI may be recommended if cancer is suspected. Ultrasound can also be used to guide liver biopsies if needed.
Biopsy
While the results of the non-invasive tests discussed above may be suggestive of liver disease, liver biopsy, in which a small sample of liver is obtained for microscopic examination, is often needed to arrive at a definitive diagnosis of liver disease. In some cases, liver biopsy may also provide clues to the cause of liver disease.
If obtaining a liver biopsy is not a possible for financial or medical reasons, many veterinarians are comfortable treating your cat empirically for liver disease with careful follow-up monitoring.
If liver disease appears suddenly in a younger cat, bacterial cholangiohepatitis is often suspected. If it comes on more insidiously in an older cat, inflammatory lymphocytic cholangiohepatitis and hyperthyroidism may be higher on the list of potential causes.
Treatment
Specific therapy will be based upon any causes of liver disease that are identified. Treatment of bacterial cholangiohepatitis, for example, usually requires antibiotics. Targeted therapy for inflammatory cholangiohepatitis usually involves a steroid like prednisolone. Surgery or chemotherapy may be recommended for neoplastic liver disease.
In addition to specific targeted therapy, adjunctive supportive therapy is important for cats with liver disease, especially if it becomes chronic. Supportive therapy for cats with liver disease may include:
- Fluid therapy to treat dehydration
- Nutritional supplementation because many cats with liver disease do not feel well enough to eat enough to maintain their weight and a healthy nutritional status. If appetite stimulants are not effective, these cats often need to have feeding tubes placed to get enough nutrition into them to avoid weight loss, which puts them at risk for hepatic lipidosis. Nasogastric tubes may work temporarily in some cats, but better long-term solutions for assisted feeding include esophagostomy or gastrostomy tubes.
- Vitamin B12 supplementation, especially important for cases of triaditis, as this vitamin often becomes depleted with intestinal disease
- Vitamin E supplementation for its antioxidant properties
- Vitamin K supplementation to replenish depleted vitamin K stores in the liver
- Ursodiol therapy, which improves the flow of bile through the biliary system
- SAMe (S-adenosyl-methionine) supplementation. SAMe is a compound naturally found in the body that improves hepatic cell membrane function and increases levels of glutathione, a powerful antioxidant. SAMe is often paired with silymarin (milk thistle), which has its own powerful anti-inflammatory benefits in the liver.
Monitoring your cat with regular physical examinations and bloodwork is important to assess medical progress and to catch and address any new secondary issues that might crop up, such as coagulopathies or dangerously low albumin (a blood protein made in the liver) levels.
The prognosis for cats with cholangiohepatitis varies based on how early the condition is caught and how compliant owners are with medical recommendations. Caught early and treated properly, some cats can be cured and others successfully medically managed for years.
