What is it?
Hepatic lipidosis (HL) is a liver problem that can
affect cats of any age, breed or sex. It is also called fatty liver
disease or fatty liver syndrome. HL occurs when a cat suffers a decrease
in appetite or stops eating completely. The decrease in caloric intake
triggers mobilization of fat stores from other parts of the body in order
to maintain metabolic requirements. The fat is processed by the liver and
in some instances it overwhelms the liver’s metabolic capacity to
metabolize it. Fat then begins to accumulate in the liver and starts to
impair liver function.
There are certain risk factors that can predispose a cat
to developing HL and certain “triggers” that may alert you to the
potential for a problem. Cats that are overweight are at a higher risk for
developing this disease. Changes in diet, environment and development of
another illness may also predispose a pet to a decrease in appetite and
development of HL. It is possible not to EVER find a reason for the
development of HL in which case it is termed idiopathic hepatic lipidosis
(IHL). In order to reach a diagnosis of IHL however, other problems need
to be ruled out.
Recent information suggests that some cats may have
intestinal disease (Inflammatory Bowel Disease) as a predisposing factor.
If that is the case long term therapy may be required.
What are the signs of HL?
Some of the first signs that people will notice is a
loss of appetite, depression, sporadic vomiting. Some owners may even
notice a yellow tinge to the tips of the ears or the whites of the eyes as
a first sign. If the problem is severe or not addressed, patients can
progress to stupor, salivation, bleeding problems and death. The earlier
the disease is caught, the better the chance of successful treatment.
How do we diagnose HL?
One of the first things that your veterinarian will do
is a physical exam to look for any obvious problems. Sometimes the patient
has an enlarged liver as a result of the fat accumulation. The next step
will be some routine blood tests to assess organ function. There are
certain changes and patterns in the liver values that suggest the presence
of HL. Other organ systems will also be evaluated for any signs of a
problem. If your veterinarian feels that the liver is indeed the source of
the problem, they may run some tests to assess your cats clotting ability.
The liver is responsible for making the proteins that make blood clot
normally as well as facilitating the activation of these proteins. If
liver function is compromised, then the blood cannot clot normally and
there is a risk of excessive bleeding.
Because an underlying disease such as an infection or
cancer may be the reason for the development of HL, abdominal radiographs
and an ultrasound are recommended. This allows visualization of the liver
to look for masses or other changes that may alert us to a different
problem.
At this point your veterinarian may recommend things
such as an aspirate of the liver or a liver biopsy. Both of these
procedures will help obtain a diagnosis of HL but both have pros and cons.
An aspirate may be preferred because it is less invasive, does not require
anesthesia and there is less risk of bleeding. The drawback however, is
that a diagnosis may be missed as it is a very small sample of cells and
not actual tissue like a biopsy. A liver biopsy may be more diagnostic but
does require anesthesia and there is a higher risk of complications. Your
veterinarian will help you decide which is the best option for the
particular situation.
How do you treat HL?
The cornerstone of therapy for HL is nutritional
support. This allows the body to reverse the metabolic derangements that
have occurred and halts progression of the problem. There are a number of
ways that nutritional support may be provided. In very mild cases, you r
veterinarian may choose to try an appetite stimulant and feeding with a
syringe until the appetite improves. This rarely works and in most
instances, more aggressive support is required. One option is the
placement of a feeding tube in the stomach. This procedure entails placing
the cat under general anesthesia for placement of a tube directly in the
stomach that protrudes from the left side of the body. This tube can then
be used to feed the pet while in the hospital as well as at home until the
cat regains its appetite. Some veterinarians may also use a feeding tube
placed in the nose which reaches down into the stomach called a
nasogastric tube. A tube placed in the esophagus may also be used – an
esophagostomy tube. The type of feeding tube used often depends on the
circumstances and your veterinarian’s preference. Because placement of
these tubes typically require anesthesia another option is to feed through
an IV (intravenous) catheter. This is called total parenteral nutrition or
TPN. TPN may allow the patient time to become a little less debilitated
and a stronger candidate for anesthesia. TPN also allows us to supply the
amino acids, fats and electrolytes needed without having to use the
intestinal system which is ideal for those patients that are vomiting.
Other ancillary treatments for this disease involve
antibiotics, acid reducers (i.e. Pepcid), specific vitamins, and treatment
of any underlying conditions.
What should I feed my cat once he/she goes home?
If your cat goes home with a stomach tube, your
veterinarian will give you recommendations on what and how to feed. It
will be important to stay in contact with your veterinarian as frequent
exams will be necessary to assess the tube, recheck lab data and monitor
weight. Once your cat begins to eat on their own, the tube feeding can be
gradually reduced and the tube ultimately removed.
With proper diagnosis, early intervention and treatment,
cats with IHL have a very good chance at recovery and will go on to lead
normal lives.
