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This page was developed to assist cat owners whose pets have been diagnosed with fatty liver or for whom fatty liver is being considered as a possible complication of another problem. Briefly, lipidosis is considered as a cause or contributing cause of liver failure when a cat that was once overweight loses weight too quickly. Often the owner is not aware that such a thing is dangerous and is pleased to see the obese cat trimming down. By the time the cat actually stops eating and is clearly sick, the disease is well underway and will require more aggressive support to reverse. The good news is that there is a good recovery rate for this condition provided it has not progressed too far.
UNEXPLAINED WEIGHT LOSS IS NEVER GOOD.
The average cat with lipidosis is middle-aged, was at one time obese but has lost at least 25% of its original body weight, has a poor appetite, and may have an obvious upset stomach (38% will have vomiting, diarrhea or constipation). Cats that are especially weak may have concurrent electrolyte imbalances or vitamin deficiencies from their liver disease.
THE CAT IN LIVER FAILURE
LIVER DISEASE VS. LIVER FAILURE
It is important to distinguish tests of liver damage (like enzymes) versus tests of liver function (like bile acids). The enzymes ALT and AST are normally held inside liver cells; when their presence is detected free in the bloodstream, this is an indicator of liver cell death. A liver can have damage without any decrease in its overall function.
A liver function test is different. In a liver function test, the liver is actually asked to do something (generally process a biochemical in a detectable way). In this way, we can see if the liver is actually in need of support and whether or not we have a good chance of getting a diagnosis through tissue sampling. Tissue sampling such as biopsy or needle aspirate is crucial to the diagnosis of liver disease. Without a tissue sample, all we can tell is whether or not the liver is in failure and specific therapy for a specific type of liver disease is not possible (though general support of the failing liver may still be possible.)
In lipidosis, there is frequently a bleeding tendency which can make harvesting a biopsy sample somewhat risky. If ultrasound is suggestive of lipidosis, it is generally safer to take a needle aspirate rather than a biopsy sample (which is a bigger bite of tissue). An aspirate showing fat infiltration is usually diagnostic especially when ultrasound shows the entire liver with a fatty texture.
A typical sequence in the diagnosis of this condition would be:
“FATTY LIVER” (HEPATIC LIPIDOSIS)
A fatty liver can develop in as soon as 2 weeks with an appetite reduction of 50-75%.
WHY WOULD THE CAT STOP EATING IN THE FIRST PLACE?
Initially there was an underlying cause of the decrease in food intake that started the cat down the slippery slope to lipidosis. If one is lucky, the underlying cause has resolved (such as the cat was lost/starved and has now been found). It is important to keep in mind that even though lipidosis usually carries a fair prognosis, in more than 90% of cases there is a second condition that requires attention, one with a prognosis that might not be so fair. Cornell University looked at 157 cats with lipidosis and looked at what conditions were primary. Here is a summary of what they found:
A lab test that might be helpful in determining underlying cause is the GGT (gamma-glutamyltranspeptidase) level. It is usually not elevated in lipidosis but would be elevated if there is an underlying additional liver disease or in the event of pancreatitis.
The cornerstone of treatment for lipidosis involves aggressive nutritional support. (In other words, a high protein diet must get into the cat to reverse the metabolic starvation state.) If this is done carefully, the recovery rate approaches 90%.
GETTING THE FOOD IN
Generally, by the time a cat has gotten into trouble with hepatic lipidosis most owners have already tried tempting cats with assorted favorite foods and gotten no results. At the point where lipidosis has developed, the cat should not be given a choice about eating; there are several methods of providing food one may enlist.
Stomach Tube/PEG Tube
This method is generally discouraged as it can be so distasteful for the cat and can create "food aversion" where the cat no longer wishes to eat normally, even after recovery, because of bad association with the manipulations needed. That said, for some cats, force-feeding is non-stressful and easily performed and spares the expense of feeding tube placement.
To provide nutrients, one must understand how much of the food product should be fed daily and how much may be fed per meal. Food is generally canned and of a consistency like hamburger. Meatballs of approximately a one inch diameter are created with one's fingers and given to the cat in the same way one would give a pill. Be careful to give the cat enough time to fully swallow the first meatball before proceeding to the next one. An entire three-ounce can of cat food can be fed in this way. If struggling results or if the cat attempts to scratch, this feeding method may be too stressful. A great deal of food is spilled during this method and it should be performed on a surface that is easily cleaned. The cat may need a "bib" made of a paper towel or cloth to avoid food matting in the coat.
BE SURE THE FOOD YOU ARE USING IS MADE FOR CATS.
A diet for a cat with lipidosis should be high protein/low carbohydrate. Ideally 35-45% of the diet's metabolizable energy should be present as protein to reverse the metabolic state of disease. Most feline recovery formulas will meet this requirement as will diets made for the management of feline diabetes. Your veterinarian will select an appropriate food based on how the food will be delivered to the cat as well as its nutritional composition.
RULES FOR NUTRITIONAL SUPPORT
GENERAL LIVER SUPPORT
There are several general therapeutic treatments that are supportive to the liver that might be used.
Low red blood cell count is a common complication of lipidosis and may be caused by Vitamin K related bleeding/clotting issues, inadequate blood phosphorus leading to red blood cell rupture, or precipitation of abnormal hemoglobin within the red blood cell (Heinz body anemia). There is approximately a 1 in 4 chance that a lipidosis cat will need some kind of blood transfusion before leaving the hospital.
When a patient has been in a starvation state for a while and then begins to eat, some serious metabolic problems may occur in the first few days as metabolism changes. When food is delivered, the pancreas releases insulin in an attempt to store the calories. Unfortunately, insulin also drives circulating potassium inside cells and cats with hepatic lipidosis are often depleted of potassium to start out with. This sudden drop in potassium can make a cat very weak (causing drooping neck, listlessness, urine retention / inability to urinate normally, heart muscle depression and more). Similarly, insulin will drive phosphate into cells in a similar way leaving the bloodstream depleted. Red blood cells will not have enough phosphate to maintain their own structure; they burst causing severe anemia.
If the blood phosphate level drops below 2.2 mg/dl, an IV supplement will be needed. After the phosphate level has started to rise, an oral supplement of phosphate (usually lactose-free cow's milk works well). Expect the cat to be monitored in the hospital for the first 3 days following initiation of nutritional support (and possibly longer).
Refeeding injury can be usually avoided by starting with half (or less) of the required amount of Calories at first and gradually working up to the full nutritional requirement over a few days. Having a low blood potassium level at the time of the initial lipidosis diagnosis is associated with increased chance of death.
IF THERE IS ONE LESSON TO LEARN FROM THIS ARTICLE, IT IS THIS:
SURVIVAL AND RECOVERY FROM HEPATIC LIPIDOSIS APPROACHES 90% WITH NUTRITIONAL SUPPORT.
Many people are reluctant to place or work with feeding tubes and want to try feeding the cat at home. There is no room for tentative treatment when it comes to this disease. Force-feeding at home can work but one must have a specific amount of food to feed and that amount must be successfully fed if the patient is to recover. Further, food aversion as described above is a real phenomenon which makes any sort of force-feeding the last choice in support. Feeding tubes are non-stressful, temporary, and highly recommended for treatment of this condition.
Cats that show a 50% drop in total bilirubin level within 7-10 days are statistically likely to survive.
Keep in mind that hepatic lipidosis rarely happens for no apparent reason. If an underlying cause is present, it must also be addressed.
Page last updated: 10/18/21