What causes liver disease in cats

Liver disease is quite common in cats and can occur at any age, from kittens to old age. Usually the signs of liver disease, like many diseases in cats, are a bit vague; affected cats are often just quiet, have reduced appetite and lose weight. Jaundice is quite often seen and if your cat has this you may notice yellowness in the eyes, mouth or skin or the urine being darker than usual.

Why does a cat get liver disease?

The liver is a large organ found at the front of the abdomen. It has many roles but generally they are connected to metabolism – the making of substances useful around the body and the processing and safe removal of many waste products and toxins.

The liver can be affected by many diseases and each individual condition has its own causes. Animals with porto-systemic shunts have an abnormal blood supply to the liver. This is a genetic condition and is more commonly seen in Persians and related breeds and Cornish and Devon Rexes. Signs are usually seen in kittens and young adults.

Young cats may be affected by the terrible virus causing Feline Infectious Peritonitis (FIP). Cats with FIP can suffer from liver disease as well as disease in other body areas.

Cysts can be seen in the livers of some cats, especially Persians and related breeds. These cysts cause more problems in the kidneys (polycystic kidney disease – PKD) and there is a genetic test as well as an ultrasound examination programme available. Breeders are currently trying to eliminate this condition.

Toxins and damage from septicaemia sometimes cause liver disease and this can occur at any age. Some cats with Feline Immunodeficiency Virus (FIV) also develop liver disease.

The most common liver diseases are those seen usually in middle-aged and older cats – inflammatory diseases such as cholangiohepatitis and lymphocytic cholangitis, hepatid lipidosis (fatty liver) which happens when the liver function shuts down due to another serious illness such as diabetes (or anything that cause the cat to stop eating); and cancers such as lymphoma or adenocarcinoma. It is not clear why particular cats are affected but being overweight will predispose a cat to fatty liver and being exposed to the Feline Leukaemia Virus (FeLV) increases a cat’s risk of developing lymphomas.

Evidence of liver damage is usually seen in the blood test results of cats with two other common diseases – diabetes mellitus and hyperthyroidism. In both of these diseases the changes should resolve once the underlying condition is controlled and liver damage does not require specific investigation or treatment.

How would I know if my cat has liver disease?

Cats with liver disease can show a variety of signs. Often signs are vague and are easily confused with signs of disease in other organs – heart failure, kidney failure, inflammatory diseases of the intestine or cancers. Cats will tend to have a reduced appetite and to lose weight; they may just seem quiet and withdrawn from their usual behaviours. You may see some vomiting and sometimes diarrhoea – usually larger quantities of liquid faeces.

Cats with portosystemic shunts may show signs of abnormal brain function – odd behaviour and seizures, failure to grow properly or weight loss.

A swollen abdomen is seen with some sorts of liver disease, usually because of fluid accumulating, sometimes from enlargement of the liver itself. Again, there are many other causes of fluid accumulation in the abdomen besides liver disease.

Jaundice is quite often seen when cats have more serious liver disease and owners sometimes notice this. You may see a yellow tinge to the skin where your cat’s skin is visible – between the eyes and ears, on the ears themselves and the lips or nose, you may also notice it in the eyes or mouth or that urine is darker than usual. Jaundice can be caused by problems other than liver disease, especially when red blood cells have been broken down rapidly (for example in cats affected by Feline Infectious Anaemia (FIA)). Pancreatitis (inflammation of the pancreas) is another cause but cats with pancreatitis often also have secondary liver damage.

Why can't my vet just prescribe some treatment over the phone?

It should be clear from the last paragraph that it’s not possible to even diagnose whether liver disease is present over the phone. It is certainly not possible to establish its cause. Your vet will need to examine your cat to make the diagnosis and often further tests are needed.

Routine blood tests run on sick cats may indicate that liver damage is happening. A further blood test called a bile acid stimulation test is used to check whether the liver is working normally. Further laboratory tests are used to help diagnose FIP, FeLV, FIV, FIA and to investigate other causes of abdominal fluid accumulation. Scanning the liver with ultrasound is now commonly used and will assist your vet to find cancers and cysts.

Most liver diseases are caused by inflammation and cancer and these can only be diagnosed by getting a tissue sample – either via a small needle or by taking a piece of tissue either using ultrasound guidance or during surgery.

Can liver disease be treated?

Some liver diseases are treated effectively with drugs – the common inflammatory diseases usually respond to drug treatments and they often need to be given for weeks, months or even for life. The prognosis is often good. Special diets often can be helpful.

There are some liver diseases that require surgery, although this is uncommon; biliary tract stones causing an obstruction require emergency surgery. Individual cancers and cysts sometimes are removable.

Unfortunately, some liver diseases do not respond well to treatment – FIP, FIV and polycystic diseases do not have good treatments. Lymphoma of the liver is a common cancer, chemotherapy may have an effect but good responses are not usual.

Cats can live quite a long time with liver cancer, even if these are malignant – depending, of course, just how ill they are when the disease is found and that any pain can be controlled.

What happens if I don't get treatment for my cat?

This all depends on the cause of the problem. Mild liver problems may well not be noticed in most cats so any problem that is bad enough to show obvious signs at home probably will not get better by itself. Sometimes evidence of liver damage is found in blood tests from a cat being examined for another reason and if there is not an obvious problem with the liver then just monitoring may be appropriate. However, your vet may want to perform other tests such as the bile acid stimulation test and an ultrasound examination to provide further information.

How can I stop my cat getting liver disease?

There are several predispositions to liver diseases to bear in mind. Avoiding FIP is difficult but there are some breeders claiming to produce kittens free of Coronavirus (the causal virus). Vaccination is available to prevent infection from FeLV and is advised for cats with outdoor access. The main avoidable risk factor for liver disease must be obesity and its link to hepatic lipidosis so regular weighing and feeding an appropriate diet to maintain your cat’s body condition in the normal range is very much recommended.

Conclusion

Liver disease is always serious and usually requires considerable veterinary input: firstly to diagnose liver disease, then to establish the exact type and cause of the pathology and its prognosis and then to guide treatment. Treatment can also be complicated and expensive, often including prolonged drug treatment and supportive care with hospitalization.

Forced feeding using tubes is often very important. Maintaining the cat’s nutrition is vital in maximizing the number of cats surviving the common treatable liver diseases.

Making the diagnosis first is important as it’s not right to provide all this veterinary care for a cat when the underlying disease has a hopeless prognosis and there are cats for whom euthanasia at the appropriate time is the kindest option.