Hepatic Lipidosis -- Fatty Liver by Frank Utchen, DVM

Dear Dr. Utchen, I recently boarded my cat for several weeks while we went away on a family vacation only to come back to a very ill cat -- she had stopped eating and developed a condition call Lipidosis. Was this brought on by the fact that she was boarded, or would she have gotten sick anyway?

Answer: Hepatic Lipidosis, or "fatty liver", is a condition where excess fat accumulates within the cells of the liver, leading to liver failure of different degrees. It is a serious condition that is far easier to treat in the early stages compared to the advanced stages.
We don't always know why this condition occurs in cats, but it can be brought on when a cat—usually an overweight cat—stops eating for a few days. In that event, changes in their metabolism associated with going into "starvation" mode can trigger the breakdown of body fat stores, and the redistribution of fat to the liver.

Unfortunately, once this process passes a certain point, a cat will begin to lose his or her appetite, at which point the process becomes a vicious cycle: lower appetite resulting in less food intake, leading to more fat redistribution in the body and more fat accumulation in the liver, causing even lower appetite, even less food intake, and even more fat redistribution into the liver. Eventually a cat will enter irreversible liver failure which is fatal.

Sometimes the only outward indication of this problem is a drop in a cat's appetite and energy level. As the appetite continues to diminish a cat will lose weight. And as the liver begins to fail, some cats will become jaundiced. Jaundice is a condition where the body's tissues take on a yellow tinge as a result of the liver failing to clean the blood of a naturally occurring compound called bilirubin which is itself yellow, and the accumulation of bilirubin in the body. This may be noticed in the skin or in the whites of the eyes.

Blood tests and ultrasound are done to diagnose this condition, and in many cases a liver biopsy is needed. Most cats require a stay in the hospital on IV fluids and appetite stimulants, although some cats can be treated with only appetite stimulants at home.

What stimulates a cat's appetite? Believe it or not, we can use small doses of valium IV while in the hospital to make cats hungry, or give them low doses of an oral antihistamine called cyproheptadine (originally marketed for children under the brand name Periactin). While those medications are effective they must be given twice a day or more often to stimulate a cat to eat.

A medication called Mirtazepine is also effective and has the benefit of only having to be given to a cat every 2 to 3 days. Once a cat begins eating and taking in adequate calories, they are on the road to recovery.

However, in some cases a cat is so sick that a flexible silicone feeding tube must be inserted either through the skin of the neck into the esophagus (an esophagostomy tube) or through the abdominal muscles directly into the stomach (a gastrostomy tube). These procedures require a brief general anesthetic.

After the feeding tube has been inserted, a cat can easily be fed adequate amounts of high calorie food by squirting it through the tube with a syringe several times a day. Cats typically tolerate these tubes well—usually ignoring its presence entirely—and when needed this is truly a life saver for some patients. The feeding tube usually stays in place for 1 to 2 weeks, during which time most cats stay at home with their owners who tend to the feedings.

In your cat's case the lipidosis may have occurred regardless of whether or not she had been boarded while you were away. However, any cat that stops eating for a few days can enter this vicious cycle. If your cat is suspected to be sensitive enough to changes of routine that staying at a boarding kennel would be likely to affect the appetite, she would probably be better off staying at home with a helpful friend coming by daily to check on her, feed her, clean the litter box, etc.