What is hepatic lipidosis and how does a cat get it?
Hepatic lipidosis is also known as fatty liver syndrome. This disease is unique to cats and is one of the most common liver diseases seen in cats.
Usually, a cat with hepatic lipidosis has recently gone through a period of anorexia (little or no eating) for three to four consecutive days. The chances of hepatic lipidosis occurring are greater if the cat was overweight or obese before the anorexia began. These cats are often middle-aged and have lost at least 25% of their body weight. In greater than 90% of cats, an underlying disease has caused the inappetence. These may include inflammatory bowel disease, other types of liver disease, cancer, pancreatitis, anxiety, respiratory disease and diabetes mellitus.
When fat is broken down rapidly to supply energy and nutrients to the anorectic cat, it can overwhelm the ability of the liver to process it. This fat becomes stored in and around the liver cells, further compromising liver function. The cat usually becomes icteric or jaundiced, as evidenced by a yellow color in the whites of the eyes or in the skin. At this point, the disease is fatal if not treated rapidly and aggressively.
How is hepatic lipidosis diagnosed?
Hepatic lipidosis is made from blood tests that demonstrate poor liver function and/or from a liver biopsy or fine needle aspirate. The latter may be performed during an exploratory surgery or by inserting a needle into the liver through the skin guided by ultrasound. The liver sample is sent to a veterinary pathologist for analysis. A cat with hepatic lipidosis will have a large amount of fat in and among the liver cells. Other diagnostic tests may be performed in an effort to determine why the cat originally stopped eating. If the cause for anorexia is treatable or resolved, the prognosis is reasonably good.
In some cases, a presumed diagnosis may be made without a liver biopsy. If a cat’s history, clinical signs, and bloodwork are strongly suggestive of the condition and the cat is too unstable to obtain a biopsy, a presumed diagnosis may be considered adequate to proceed with treatment. Further tests may be required however, if your cat develops additional clinical signs or does not follow the expected course of the disease.
Is this a treatable disease?
Hepatic lipidosis is treatable with aggressive nutritional support until a normal appetite returns. A consistently high level of nutritional support is required for the liver to resume functioning so it may mobilize the excessive fat stores. This takes an average of six to seven weeks. Therefore, a method of feeding such as a feeding tube, must be used that allows you to feed your cat at home. This enables your veterinarian to know the exact amount of food and nutrients your cat is receiving.
"Hepatic lipidosis is treatable with aggressive nutritional support..."
While nutritional support is the most important component of treatment, many cats are also treated with medications to support liver function, decrease nausea, and correct electrolyte imbalances. Cats may also be hospitalized for intravenous (IV) fluids during the first several days of treatment, in order to correct dehydration. Treating the underlying initial cause of the inappetence is also essential for full recovery.
How do I provide the necessary nutritional support?
A feeding tube is surgically implanted into your cat, so you can syringe-feed a special diet directly into your cat’s gastrointestinal tract. The feeding tube may be placed into the esophagus or the stomach (see the handouts "Tube Feeding in Cats", "Esophagostomy Tube Feeding in Cats" and "Gastrostomy Tube Feeding in Cats" for further information). Your veterinarian will determine the best one to use with your cat, depending on the particular circumstances.
You will need to use a syringe to feed your cat a special food mixture through the feeding tube three to five times per day. This food is formulated to meet the cat's nutritional needs; it should not cause vomiting or diarrhea. To feed your cat, follow these steps:
- Mix one can of prescription food (provided by your veterinarian) with water. The exact quantity of water required will vary, depending on the size of your cat’s feeding tube. Your veterinarian will provide instructions.
- Remove the cap from the feeding tube.
- Using the syringe provided, inject _____ ml/cc of the food mixture into your cat's feeding tube. Feed your cat times _____ per day FOR A TOTAL OF ________ ml/cc PER 24 HOURS. It is helpful to inject the food slowly, about 1 ml/cc per second, and to elevate your cat's front feet so the food goes easily into the stomach.
- After the food has been injected, inject 5-10 ml/cc of tap water through the tube to flush any remaining food and prevent clogging. Replace the cap in the tube.
- Any remaining food should be stored in the refrigerator. Before the next feeding, it should be warmed to body temperature under hot tap water or in a microwave oven. If you heat it in a microwave oven, be sure to mix the contents thoroughly prior to feeding because of the potential for uneven heating. Also, always check the temperature prior to feeding to be sure that the food is not too hot by placing food on the back of your hand.
NOTE: Technically, a cubic centimeter (cc) and a milliliter (ml) are slightly different. However, for our purposes, a cc is the same as a ml. Syringes are often marked in cc's.
When is the tube removed?
The average cat requires six to seven weeks of tube feeding before it begins to eat on its own after an episode of hepatic lipidosis. At least once weekly, offer your cat a small amount of its favorite food by mouth so that you will know when her appetite returns. The feeding tube will not hinder eating in any way.
Once your cat begins eating on her own, you can gradually decrease how much you are feeding via the feeding tube. Monitor how much your cat is eating and aim to keep the daily food intake constant, gradually decreasing tube-feeding as your cat’s appetite increases. Once your cat has been eating well for three to four days, without any supplemental tube-feeding, the tube can be removed by your veterinarian. Removal of the tube is often simple and does usually not require anesthesia; however, you should not attempt to remove the tube yourself.