Fatty Liver Disease (Hepatic Lipidosis) in Cats

The liver is a vital organ that performs many critical functions, including metabolizing toxins which are then eliminated by the kidneys and bowel. If the liver is unable to function properly, toxins accumulate in the bloodstream, which can be fatal.

Cats with fatty liver disease (FLD) require emergency veterinary attention. All cats who stop eating for a period of more than two days, whether because they are ill or because they are stopped from eating either voluntarily or involuntarily, are at risk.

The severity of FLD depends on the presence of an underlying condition, the amount of fat made available for energy production, and how soon treatment is started after symptoms develop.

In cases where there is an underlying health condition, severity depends on the nature of that illness.

Fatty liver disease is common in cats, particularly in ill cats who stop eating due to feeling unwell.

Overweight cats are particularly at risk, because they have enough stored fat to easily overwhelm the liver. Middle aged cats are also more susceptible.

Cats who are overweight or obese tend to have more severe cases of FLD because there is more fat in the body to mobilize to the liver.

In cases where treatment is delayed, toxins accumulate in the blood and other systems, including the brain. In these cases, hepatic encephalopathy (HE) can develop. HE occurs when the liver cannot remove the toxins, particularly ammonia, from the body. Ammonia accumulates and begins to affect the function of the brain.

In general, FLD is caused by not eating. When a cat does not eat for two or more days, the body releases fat to produce energy. Fat travels to the liver to be processed. When excessive amounts of fat are released at one time, it overwhelms the cells of the liver, stopping it from properly performing its many crucial functions. The toxins that the liver usually removes from the body accumulate within the bloodstream and begin to affect other organ systems. Without treatment, these toxins accumulate to the point of fatal blood toxicity.

The underlying cause of not eating is due to illness or due to lack of access to food. Appetite loss is a symptom of many conditions in cats.

Causes of lack of access to food include

• Overzealous calorie restriction in weight management efforts
• A change in feed that the cat does not accept
• Being accidentally locked away from food
• Pain in or around the mouth

Other symptoms vary depending on the presence of an underlying cause of appetite loss.

Cats who have not eaten for two or more days require emergency veterinary attention.

Diagnostic tools include:

• Physical examination
• Bloodwork
• Urinalysis
• Diagnostic imaging including X-rays and ultrasounds
• Liver biopsy
• Fine needle aspiration of liver

Treatments are aimed at reversing dehydration, electrolyte imbalances, and metabolic deficits, and providing nutrition. These include:

• IV fluids
• Electrolyte therapy
• Liver supporting supplements
• Anti-nausea medications
• Appetite stimulants
• Nutritional support

In some cases nutritional support through tube feeding is required for several months.

In cases where fatty liver disease has developed into hepatic encephalopathy, treatments include:

• Supportive care
• Cleansing enemas
• Retention enemas
• Probiotic therapy

After recovery, ongoing dietary restrictions are recommended to balance protein levels.

Left untreated, FLD is progressive and quickly becomes life-threatening. With early detection and treatment, FLD is reversible with a good prognosis. Most cats recover in 3-6 weeks. Tube feeding may be required for several months for full recovery. FLD typically does not recur after it resolves, and most cats have no long term damage to their liver function.

In cases where FLD is a complication of an underlying condition, treatment of the primary condition is required for complete resolution of illness.

Preventive measures aim to keep the cat healthy, eating properly, and maintaining a healthy body condition. These include:

• Regular check ups to diagnose and treat underlying causes early
• Making changes to food and feeding practices gradually
• Maintaining appropriate caloric intake with high quality food and limiting access to treats and human food
• Careful observation of eating habits to catch appetite loss or lack of access to food early

Fatty liver disease is the most common form of liver disease in cats.

• Supportive care
• Medications
• Treatment of underlying conditions