In a normal circulatory system, the lymph vessels collect lymphatic fluid from the body tissues and return them to the blood. With congenital lymphangiectasia, the lymph vessels are abnormally enlarged and leak fluid into the intestines. Special lymph vessels in the intestines called lacteals can burst. Because these lacteals are designed to absorb fats, fats and proteins are lost when they burst.
You may have heard in human medicine that lymphedemia is often experienced by women who have had surgery because of breast cancer. The associated lymph nodes are removed, and fluid collects in the arm. This is the same process as in dogs with lymphangiectasia — in canines, the fluid collects in the abdomen.
Symptoms include nausea, vomiting, diarrhea, and abdominal pain. There may also be swelling in the abdomen. Conversely, the dog might lose weight. These symptoms, however, can indicate a number of disorders known collectively as protein-losing enteropathies. Tests are required to pin down a definitive cause.
Blood work will show a low lymphocyte count, low cholesterol levels, and low albumin levels. While these are all suggestive of lymphangiectasia, the definitive diagnosis requires a biopsy. The biopsy may be done via surgery or endoscopy. A biopsy showing enlarged lymph vessels indicates lymphangiectasia.
Treatment and Prognosis
The first goal of treatment is to reduce inflammation. Corticosteroids are commonly given, sometimes with diuretics to reduce fluid accumulation. The second goal is to reduce the pressure in the lymph vessels while restoring normal protein levels. Dietary modification can help here, with a low-fat, high-quality protein formulation. You may have to give a supplement of fat-soluble vitamins because the dog will not absorb these well.
Lymphangiectasia cannot be cured, but it can often be well managed throughout the dog's life, with only occasional symptomatic episodes.