By Dr. Becker
Feline hepatic lipidosis, also called fatty liver syndrome, is a very serious condition and the most frequently diagnosed liver disease in cats in the U.S. Interestingly, the disease doesn't occur in any other animal — just kitties. Hepatic lipidosis is most often seen in middle-aged, overweight cats who experience sudden weight loss. The condition can be secondary to another disease, but is most often a primary idiopathic (no identified cause) condition.
Known Triggers for Feline Hepatic Lipidosis
A sudden loss of appetite or significant cutback in caloric intake is the most frequent predisposing factor for feline hepatic lipidosis. Environmental stressors can cause appetite loss in cats, as can more serious problems such as heart disease, kidney disease, chronic feline lower urinary tract disease (FLUTD), upper respiratory disease, cancer and pancreatitis.
But believe it or not, I most often see this condition after a pet parent decides to change their cat's diet and the kitty simply refuses to eat the new food. Many people mistakenly believe, "If my cat gets hungry enough, he'll eat." This isn't necessarily true, and it's a dangerous assumption.
Cat guardians need to monitor their pet's appetite and food intake every day. If your kitty refuses to eat, she should be seen by a veterinarian right away. After a few days without adequate daily calories, your cat's body will begin sending fat cells to the liver to convert to energy. That's where the problem begins, because sedentary cats don't metabolize fat very efficiently.
Felines are designed by nature to move quickly, kill small prey and eat several times a day. They weren't built to eat large meals or nibble constantly throughout the day. Left to their own devices cats are very active, lean animals whose bodies aren't meant to store much fat.
This is why from an evolutionary standpoint, sedentary and overweight cats' livers can't handle the fat mobilization that occurs in response to lack or insufficient quantities of food. The buildup of fat cells in the liver prevents normal functioning. Left untreated, the liver ultimately fails, and the cat dies.
Symptoms of Fatty Liver Disease
Symptoms of fatty liver syndrome include:
- Excessive drooling (caused by nausea)
- Weight loss
As the disease progresses, there can also be lethargy, jaundice (yellowing of the skin), dramatic weight loss and occasionally, seizures.
Diagnosing Hepatic Lipidosis
Definitive diagnosis of feline hepatic lipidosis is made through a liver biopsy, which will show excessive amounts of fat within the cells of the liver. Since a liver biopsy is invasive and requires anesthesia, a reasonably accurate diagnosis can also be made by taking a history of your cat's eating habits and checking for weight loss, muscle atrophy and/or jaundice.
Abdominal ultrasound will show any enlargement of the liver, and blood tests can reveal problems with liver function, so it's possible to get a pretty accurate diagnosis just from the history, physical exam, abdominal ultrasound and bloodwork.
Feline hepatic lipidosis is very treatable when caught early. The disease can occur within a couple of days in kitties who've stopped eating. In cats who continue to nibble at their food but don't eat enough to sustain their body weight, it can take as little as two weeks for fatty liver disease to develop.
Nutritional support is the treatment for this disease. This unfortunately means force-feeding, often by tube, until the kitty's natural appetite kicks back in. The tube-fed diet is liquid and should be balanced — it's often called a recovery diet for metabolic balance, and it is designed to place minimal stress on the liver.
Sometimes a feeding tube must be inserted into the cat's stomach through an incision in the side or through the nose or esophagus. You'll need to feed your cat through this tube until he's voluntarily consuming food on his own again. It typically takes four to six weeks for recovery with nutritional support, but it can sometimes take as long as 18 weeks.
Cats with hepatic lipidosis may also benefit from cobalamin (vitamin B12). In a study of 80 cats with the condition, 40 percent had low cobalamin levels.1 Kitties with the condition may also have a vitamin K deficiency, in which case vitamin K therapy may be instituted. N-acetyl cysteine (NAC) and the amino acid carnitine may also be of benefit during recovery.
During tube-feeding treatment, kitties should also be offered small amounts of their regular food. I recommend at least once a day offering regular food, because as soon as your cat is consistently eating on her own, the feeding tube can be removed by your veterinarian.
It will be necessary around the same time to run more blood tests to insure kitty's liver enzymes are back to normal. Most cats go back to their regular lives after treatment, with follow-up bloodwork as necessary. I also recommend talking with a holistic veterinarian about liver detoxification supplements such as milk thistle and SAMe.
Cats suffering from an advanced stage of hepatic lipidosis, with jaundice, seizures or other secondary metabolic problems require hospitalization. These kitties will need IV fluids to treat dehydration and promote the flushing action of the liver.
There are many reasons why cats lose interest in food. It's very important to find the root cause of your kitty's anorexia and treat it before hepatic lipidosis has a chance to develop.
Sometimes a painful mouth or social or emotional stressors such as adding another pet to the family will cause a kitty to stop eating. And sometimes there are several things occurring simultaneously, so the goal is to sort it all out to determine the cause(s) of your cat's lack of appetite.
Since we see this disease most often in obese cats who suddenly drop a significant amount of weight, needless to say, the best prevention is to not let your cat get fat in the first place. If your kitty is already heavy, it's extremely important not only that she lose weight, but that it's done very, very slowly.
You can find lots of information here at Healthy Pets on how to safely diet your pet down to a healthy weight, including Valuable Tips for Helping Your Heavy Cat. One thing I strongly advise against is free-feeding, also known as the all-day, all-you-can-eat buffet featuring dry cat food. While it's true your cat won't go hungry, it's also true that free-feeding is linked to obesity in kitties.
A better approach is to feed species-appropriate meals at the right calorie count twice a day. It's much easier to maintain your cat's ideal body weight by feeding a precise number of calories in the morning and again in the evening. Also, if you're interested in transitioning your cat to a better-quality diet (from dry to canned, for example, or from canned to raw), it needs to happen very gradually to insure kitty is getting the calories she needs every day.
If your cat suddenly refuses to eat, make an appointment with your veterinarian right away. When a dog doesn't seem hungry, it's safe enough to wait a day or two before considering calling the vet. With kitties, anorexia warrants an immediate vet visit. If your cat's appetite falls off and you notice she's just nibbling at her food, it's okay to monitor the situation for a day or two. But if within a couple of days she still isn't eating normally, it's time to make an appointment with the vet.
Unlike humans, dogs and many other animals who can safely fast, cats cannot healthfully go without food for days. So it's important to keep a watchful eye on your pet's calorie consumption and contact your vet if you see her appetite falling off.