Strictly speaking, hepatitis is a chronic liver inflammation. Feline hepatitis is however commonly used term to describe number of liver conditions in cats.

Feline hepatic lipidosis is the most common type of liver failure in cats, followed by cholangiohepatitis. These two types of hepatitis in cats account for about two-thirds of all feline liver diseases.

Other feline liver diseases include infectious liver diseases like feline infectious peritonitis and toxoplasmosis.

Feline liver cancer and leukaemia that begin in the liver or spread there from other locations can also cause liver insufficiency.

Feline liver failure symptoms can be vague and non-specific. Early symptoms often include loss of appetite, weight loss, diarrhoea, and vomiting. As the feline liver disease progresses the symptoms become more severe, like ascites (build-up of fluid in the peritoneal cavity), jaundice, and seizures.

You should always seek professional advice if your cat is showing any sudden or prevailing abnormal symptoms or behaviour. As they say, it is better safe than sorry.

This section covers the most common feline liver diseases:

- Feline hepatic lipidosis

- Cholangiohepatitis

- Acute hepatic failure in cats

- Feline infectious peritonitis

- Feline toxoplasmosis

One of the many functions of the liver is to produce bile, but it helps in the digestion of fats. Cholangitis is an inflammation of the bile ducts and when the liver is also inflamed, it is called cholangiohepatitis.

There are three main types of feline cholangitis:

Neutrophilic Cholangitis

Is a bacterial infection from the intestine causing inflammation? Neutrophilic cholangitis starts as acute but can become chronic if not treated aggressively early on. Symptoms of acute neutrophilic cholangitis include sudden loss of appetite, vomiting, diarrhoea, fever, abdominal pain, and jaundice.

Treatment with appropriate antibiotics and supportive care is required, but the prognosis is usually good if treatment is started early on. If the disease becomes chronic then treatment will include immunosuppressive drugs (corticosteroids) as well.

Lymphocytic Cholangitis

Is a non-infectious inflammatory liver disease that usually causes enlargement of the liver and can cause fluid accumulation in the abdomen (ascites). Treatment consists of anti-inflammatory and immunosuppressive drugs (corticosteroids). The prognosis varies on the severity of the condition so early diagnosis is important. In some cases, prolonged or life-long treatment is required, and relapses can occur.

Liver Fluke

Feline liver fluke (Opisthorchis felineus) is a trematode parasite (flatworm) that lives in water and is only found in subtropical and tropical areas. The severity of symptoms depends on the severity of infection. However, most infested cats remain asymptomatic (have the parasite but do not show any symptoms). Treatment can include medication to kill trematode spores and parasitic worms, as well as antibiotics and prednisone.

Supportive care is in all cases necessary as well, i.e. to allow the biliary system and liver to heal, and to support the cat's recovery.

Supportive feline cholangitis care includes vitamin K injections, pain relief, proper nutrition (may require feeding tube), Ursodeoxycholic acid (to improve bile flow and decrease inflammation), as well as SAM-e and other antioxidants supplementation.

Feline hepatic failure or acute liver failure in cats is a condition characterized by sudden loss of 70% or more of the liver's function due to sudden, massive tissue death in the liver. Necrosis (tissue death) sets in, causing loss of liver enzymes and impaired liver function, ultimately leading to complete liver failure.

Feline liver failure symptoms include the common gastrointestinal symptoms like vomiting, diarrhoea, and blood in the stool. But acute feline hepatitis failure can affect the body through a number of other system failures (PetMD):

- Nervous System: hepatic encephalopathy (brain disease related to liver failure)

- Nepatobiliary: the liver plus the gallbladder; jaundice, necrosis (tissue death) of the liver cells and bile duct cells

- Renal: the tubules of the kidney may be injured from toxins/metabolites

- Immune / Lymphatic / Hemic: imbalances in the blood and lymphaticsystems, may lead to coagulant (clotting) complications

Acute liver failure can be fatal if left untreated. In most cases, hospitalization is required, i.e. for IV fluids, electrolytes, and oxygen, as well as colloid replacements.

Activities have to be restricted for a while to allow time for the liver to regenerate. Vitamins (E and K), antioxidants, and liver supplements for cats (like maxxiSAMe) are also beneficial after acute liver failure.

Feline infectious peritonitis (FIP) is a viral disease caused by certain strains of a virus called feline coronavirus. It affects many systems of the body, including the liver. Feline infectious peritonitis is a progressive disease and is unfortunately in most cases fatal.

Infection with coronavirus is actually quite common in cats but fortunately in most cases it does not cause any health problems. But sometimes the virus changes to the strain of coronavirus that causes FIP.

Most cats that develop feline infectious peritonitis are under two years of age though cats of any age may develop the disease. Cats with weak immune systems (e.g. kittens, cats with leukaemia, geriatric cats) are most likely to develop feline infectious peritonitis.

Currently there is no known cure for feline infectious peritonitis so the disease is in most cases fatal. Treatment therefore consists of supportive care, i.e. good nutrition and medication, like corticosteroids, antibiotics, and cytotoxic drugs. IV fluids, draining accumulated fluids and blood transfusions are also used when applicable.

Even though feline infectious peritonitis is not highly contagious disease, it is important to take care in multi-cat households and avoid overcrowding. Good hygiene is another essential strategy for minimizing the risk of FIP.