Symptoms of chronic liver disease in cats may be difficult to detect until the disease is in advanced stages. The liver has excessive tissue and is capable of partial regeneration. The liver performs multiple metabolic functions including detoxifying ingested substances, removing waste from the bloodstream, metabolizing fats, storing carbohydrates, producing bile, producing plasma proteins and sugars, and contributing to blood clots.
Visual Symptoms of Chronic Liver Disease
A common sign of liver disease is jaundice, or icterus, that is caused by an accumulation of bile in the body tissues. The skin and mucous membranes will appear pale or yellow and the whites of the eyeballs can appear yellow. The abdomen may appear swollen or bloated due to acites, the accumulation of fluid in the abdomen. This may also cause the cat's abdomen to be painful to the touch. Other symptoms that may be visible to the owner include:
- Decreased appetite or anorexia
- Weight loss
- Weakness
- Depression
- Vomiting
- Diarrhea
- Excessive water consumption, or polydipsia
- Excessive urination, or polyuria
- Bad breath
- Small hemorrhages in gums
Advanced stages of chronic liver disease may result in impairment of the central nervous system. The cat may behave blind or press its head against surfaces and may ultimately experience seizures, coma or death.
Clinical Symptoms of Chronic Liver Disease
Symptoms may vary with the extent of damage and the region of the liver that is affected. Multiple laboratory tests are necessary to diagnose the type and severity of liver disease and damage. Clinical laboratory findings that may indicate chronic liver disease include:
- Internal bleeding (stomach, intestine, urinary tract)
- Increased ALT enzyme (alanine aminotransferase)
- Increased AST enzyme (aspartate aminotransferase)
- Increased AP
- Increased bilirubin
- Decreased blood urea nitrogen
- Low blood glucose
- Low blood albumin
- Low potassium and cholesterol
- Anemia
In conjunction with laboratory blood and urine tests, an ultrasound or x-ray of the cat's abdomen can confirm a diagnosis. This will display if the liver is enlarged, if tumors are present or if there is an obstruction of bile flow. A surgical removal of a liver tissue sample, or biopsy, may be necessary to determine the type of liver disease.
Causes of Chronic Liver Disease
There are different causes of chronic liver disease in cats and treatment is dependent upon the cause and stage of the disease. Treatment may result in full recovery, but is often administered only to control the disease.
Idiopathic hepatic lipidosis, or IHL, is unique to cats and the most common cause of liver disease and failure. The cause of IHL is unknown, but overweight cats are believed to be predisposed and stress can be an initiating factor. Cats with IHL experience anorexia that results in treatment of intravenous fluids along with force feeding or appetite stimulation.
Cholangitis is an inflammation of the liver that is often related to infection. Feline infectious peritonitis, toxoplasmosis (parasites) or bacterial infections are common causes of liver inflammation. Feline leukemia and other cancers can be causes of chronic liver disease, but cancer originating from the liver itself is uncommon in cats.
Toxins such as insecticides, copper and lead can damage the liver, or cause toxic hepatopathy or chronic liver disease. Toxic hepatopathy can also be caused by excessive or long term doses of acetaminophen or prescription antibiotics, anticonvulsants or steroid preparations.
A liver shunt, or portosystemic shunt, prevents the liver from detoxifying blood before entering circulation. Liver shunts in cats are often congenital and cats will show symptoms before they are 12 months old.