Fatty liver (hepatic lipidosis) in cats

Hepatic lipidosis is also known as ‘fatty liver disease’. It is a disease that is more common in middle-aged cats, although it can affect cats of any age. In fatty liver disease, fat builds up in the liver and this affects liver function with wide-ranging effects for your cat, which can be very serious.

Fatty liver disease occurs when excess fat is taken up by the cells within the liver and accumulates in large amounts. This affects the function of the liver, resulting in a wide range of effects. The disease develops for various reasons and is a particular concern when a cat stops eating for any reason, or is unable to eat for a period of time (eg being lost or locked in by mistake). This is one reason why it is important food is never withheld from a cat (eg when a cat is on a diet, or the diet is changed and the cat doesn’t like the new food). Always seek veterinary attention when a cat refuses food or eats less.

As soon as a cat eats less than they should, for even just a couple of days the body starts to break down fat stores to supply energy. Fat is normally processed in the liver to provide energy but, if the breakdown of fat stores happens too quickly, the liver can be overwhelmed.

Overweight cats may be at higher risk, but the condition can occur in cats of any size. Hepatic lipidosis can happen when cats are feeling unwell from another disease (eg pancreatitis, intestinal disease) and therefore eat less, and then become even more unwell due to the fatty liver disease.

You may notice your cat refusing food, leaving food or eating less. They could lose weight, but some cats lose more muscle than fat so their weight on the scales may not alter.

As the disease progresses your cat may be sick (vomit) or have diarrhea. It is likely they will seem very tired and may sleep a lot and be less keen to play or interact with the family and other pets. They may seem weak and depressed, and you might notice the whites of their eyes and their gums are yellow-tinged (jaundice). Occasionally cats with severe liver disease can drool, stare into space and even twitch or tremble as the build-up of toxins affects their brain.

The signs of fatty liver disease are vague and can be seen with many other conditions. Your veterinarian will need to run some tests to try to find out what is the causing your cat to be unwell, and if other conditions are present that have resulted in the liver disease. Tests will start by taking a blood sample to send to laboratory or test in the clinic and may show elevated liver enzymes and high bilirubin (the substance that causes the gums/eyes to be yellow).

Cats with liver disease often have problems with blood clotting so your veterinarian will want to check that your cat’s blood clots normally before further investigations are performed.

Your veterinarian may also want to take your cat into the hospital for X-ray or ultrasound investigations. These may show an enlarged, bright liver, and further tests may be recommended.

To confirm the diagnosis a sample of liver tissue is needed. Your veterinarian may be able to insert a needle into the liver during an ultrasound examination and collect a sample. If this is not possible a biopsy will need to be taken from the liver at surgery or laparoscopy (camera study).

The first priority in fatty liver disease is to stabilize your cat’s condition. Your veterinarian will probably admit your cat to the clinic and put them on a drip to provide fluids and electrolytes. They may need medications including antibiotics, pain relief, anti-sickness treatment and nutritional supplements and vitamins. The main priority is that cats receive nutrition as soon as possible, otherwise the disease will continue to get worse. In many cats this means that some kind of feeding tube will need to be placed, as cats are unlikely to eat of their own choice when they feel unwell. The tube may also allow other medications to be given without the stress of tablets. The most commonly placed feeding tubes are naso-esophageal (through the nose) or esophagostomy (through the neck) or occasionally directly into the stomach (gastrostomy). Cats generally tolerate these tubes very well and can even come home with them in place so they can be fed and receive medications in their own environment. Most cats will be given a special high protein diet, depending on their other conditions and severity of illness. Some cats may be transferred to a specialist hospital for care if they are very unwell.

Severe hepatic lipidosis can be challenging to treat and it can take several weeks for the cat to recover. Recovery will also depend on underlying other illnesses, the cat’s condition, severity of changes on blood tests, age and response to treatment. Most cats can recover with careful management, but it can take several weeks and recurrence of illness it possible. Ensuring your cat has a healthy body condition (avoiding obesity) and seeking prompt veterinary attention if they are unwell or eating less can help avoid fatty liver disease.