(This information is meant only to inform and educate you, it does not
replace Veterinary treatment. Always take your pet to your Vet for a
proper diagnosis of a health problem)
Protein-losing enteropathy is a fancy way of saying that protein is being
lost from the body through the intestine. This is a serious problem as the
body's proteins are not easily replaced and the only way to replace them
involves the absorption of protein constituents (the amino acids that make
up proteins) from the intestine. If the intestine is actually leaking
nutrients out instead of absorbing them in, the result is a nutritional
disaster. Protein Losing Enteropathy is an inherited immune-mediated
disease of the intestines. Many dogs don't show clinical signs of this
disease until they are over the age of 5. Abnormal fluid accumulation may
occur secondary to decreased protein levels in the blood.
The mechanism for protein loss in protein-losing enteropathy
may be related to inflammation or erosion affecting the normal barrier
function of the gut, or to acquired or congenital abnormalities in
intestinal lymphatic or vascular drainage.
The most important protein-losing gastroenteropathies are associated with
chronic inflammatory diseases and circulatory diseases such as impaired
drainage of lymph glands of the digestive tract. When loss of plasma
proteins is by protein-losing enteropathy due to inflammation, there are
often associated clinical signs of gastrointestinal disease such as
vomiting, loss of appetite or diarrhea that suggest an underlying problem
in the gastrointestinal tract.
Protein-losing enteropathy is one mechanism contributing to weight loss in
gastrointestinal disease. In some cases there is severe loss of proteins
such that the body can not maintain proper plasma protein concentrations.
This may be so severe that fluid will accumulate in the abdominal cavity or
The main protein that one cannot
afford to lose is called albumin. This protein normally is produced by
one's liver and circulates in the bloodstream acting as a carrier for
biochemicals that require transport but cannot actually dissolve in blood.
Albumin can be considered sort of a mass transit system in the
bloodstream, a bus or subway, if you will, carrying important biochemicals
from one place to another. Albumin, by being the most prevalent
blood protein, also is responsible for actually keeping water in one's
bloodstream. When water cannot be held within the vasculature, it leaks
out causing fluid accumulation in tissue (i.e., edema) or in within the
chest or abdomen (i.e., effusion).
Of course, in a protein-losing enteropathy, other proteins are lost, too.
Antibodies, proteins of blood clotting, enzymes, etc. all leak out the
intestine and are forever lost in the feces that exit the body. The
body tries hard to maintain its albumin level by extracting protein from
other sources (like muscle), and having the liver make albumin from the
components of these other proteins. This may help maintain a workable
amount of albumin in the bloodstream but it comes at the expense of muscle
tissue and other protein.
Animals with protein-losing enteropathies usually exhibit signs of weight
loss (muscle wasting and decreased body fat). There may be vomiting and
diarrhea and fluid
accumulation in the abdomen can create a bloated appearance, but these signs are by no means always seen, and it should be
emphasized that failure to exhibit diarrhea or other characteristic signs
of gastrointestinal disease does not eliminate the possibility of
Signs related to the underlying disease responsible for protein-losing
enteropathy may be present, and physical examination may reveal evidence
of thickened bowel loops, an abdorninal mass, or cardiac abnormalities. If
hypoalbuminemia is severe then this may be responsible for the sole
presenting signs (swelling of the limbs,fluid accumulation in the
abdominal cavity, or difficult breathing due to fluid accumulation in the
chest cavity). Limb swelling and fluid accumulation in the abdomen are
generally present when the serum albumin concentration decreases.
How is A Diagnosis Made?
In most cases, an obviously sick dog is brought to the veterinarian.
Sometimes the above classical signs are present but sometimes there is no
specific hint of this condition until blood test results are in.
Low lymphocyte count: Animals with lymphangiectasia have lymphocytes
rolling out their lacteals and into their intestine. The low blood
lymphocyte count is so consistent with lymphangiectasia that it is
difficult to make this diagnosis if this finding is not present.
Low cholesterol: Cholesterol is part of the lymph fluid being lost.
Low albumin level: Low blood albumin level is the most consistent finding
in lymphangiectasia, though it is possible to have lymphangiectasia in a
small portion of the intestine only and still maintain a normal albumin
level. There are only four ways a patient can develop a low albumin level.
A protein-losing enteropathy
Glomerular disease (such as glomerulonephritis) in which albumin is lost
through diseased kidneys
Reduced albumin production in the liver due to liver failure
Serum leakage through extreme skin damage (such as third degree burns)
These conditions can be easily ruled out one by one. It is obvious if
third degree burns are present. If there are none, a routine urinalysis
will indicate if there is significant protein loss in the urine and if
glomerular disease should be pursued. A liver function test such as a bile
acids test will indicate whether or not there is liver failure. If none of
these three conditions are present, then there must be a protein-losing
Treatment and What to Expect
The first step in treatment is to address the underlying cause. In most
cases of lymphangiectasia, the underlying cause involves inflammation and
most treatment of lymphangiectasia involves suppression of inflammation.
Medications such as prednisone and/or azathioprineare commonly used,
especially if inflammatory bowel diseaseis present.
The second step in treatment is dietary though success has been mixed.
Traditionally, rather nasty-tasting medium chain triglycerides have been
used in lymphangiectasia treatment. Triglycerides (a fancy word for fats)
are very long molecules. Some are longer than others. The more usual
dietary fats are called long chain triglycerides and, when absorbed into
one's body, must be repackaged into fat globules called chylomicra, and
are normally absorbed into the lymph vessels. In lymphangiectasia, we want
to reduce the pressure in the lymph vessels. We want less lymph. The idea
was that if the patient ate shorter fat chains, the fats could be absorbed
right into bloodstream directly and bypass the lymph system altogether.
Whether or not this actually happens is still a matter of controversy but
adding medium chain triglycerides (or MCTs) in conjunction with a low fat
diet are common recommendations in the therapy of lymphangiectasia.
Other treatments include the use of diuretics (such as furosemide to help
increase urination and ultimately reduce fluid accumulation in the chest
or abdomen. Actual tapping of the body cavity and suctioning the fluid
affected may be needed periodically.
If the underlying condition is treatable then prognosis for
lymphangiectasia is good. It should be understood that lymphangiectasia is
unlikely to be cured and at best can be managed.