Liver damage in cats is caused by many similar causes of liver damage in humans. These include the excess absorption of toxins in the diet that the liver is responsible for cleansing from the body and which cats often acquire through their diet. Other common causes are related to the natural aging process where the liver starts to fail, and various types of infections and cancer. One of the most common causes of liver damage in cats, however, is idiopathic hepatic lipidosis. This is a complicated term that simply translates as an excess of fatty tissue in the liver, as idiopathic means an unknown cause, hepatic refers to the liver, and lipidosis refers a disorder in fat metabolism.
When someone refers to feline liver disease as Fatty Liver Disease, it is really just a catch-all term to describe the fact that a cat has stopped eating and this causes fat tissue in the body to be broken down in the liver for energy. This causes the liver to deteriorate further, but it is likely just a secondary symptom to an underlying cause that prompted the cat to stop eating in the first place, such as feline diabetes, urinary tract or respiratory infections. When liver damage in cats occurs, it is undiagnosable in up to 50% of cases due to the fact that some previous underlying cause has contributed to it over a protracted period of time. Overweight and older cats are predisposed to both feline diabetes and Fatty Liver Disease.
If liver tests confirm that the cat has feline liver disease, the treatment involves appetite stimulants, special diets, or possibly the insertion of a feeding tube. Cats that have still been eating some food by this point and survive the first four days of treatment are very likely to recover within two to three months. The feeding tube has to remain for six to eight weeks, however, and the cat has to remain hydrated in order for the prognosis to be good. When cats get aggressive nutritional treatments for a fatty liver, their chance of recovery is estimated at up to 90%, because a cat's liver is not very effective at breaking down fat in general and the condition can be easily treated. If a cat has stopped eating entirely, however, or it does not receive aggressive treatments, its chances of recovery drops to between 10% and 15%.
Several other common causes for liver damage in cats also exist, including an infection known as Cholangiohepatitis, where bacteria in the small intestine spread to the gallbladder and liver. The signs of liver disease in cats with Cholangiohepatitis can be rather broad, and may seem minor such as reduced appetite and depression. They can also include periods where the cat becomes violently ill and displays vomiting and diarrhea. Treatments for infections also can include a feeding tube, antibiotics that must be taken for three to six months, and vitamin supplements such as vitamin E and milk thistle to help the cat's liver heal over time. In extreme cases, powerful and risky immunosuppressive drugs are prescribed such as prednisone to control natural immune responses to related conditions such as bowel disease, while the other treatments improve the cat's overall condition.
Another major cause of liver damage in cats is due to the liver's inability to process toxins obtained via additives in their food, from drugs or household chemicals, toxic plants, or other materials that the cat has ingested. These conditions can be treated through poison control center practices that a veterinarian employs. They can be fatal if not caught early, as they are a sign of acute hepatic failure in cats, versus long-term chronic conditions caused by infections or a fatty liver that are more gradual in nature.
Liver damage in animals such as cats, dogs, and other mammals often runs parallel to liver conditions in people. Liver cancer is generally uncommon in cats, but cancer in other parts of their body often will spread to the liver, especially with old age and deteriorating health in general. A unique problem with cat physiology not common to other mammals is the occurrence of a Portosystemic shunt. This can cause liver damage in cats because its a problem where blood is channeled past the liver instead of being processed by it, so that the liver fails to detoxify the blood. Such shunts can be present from birth or can develop over time, but usually show up within the first year of a cat's life.