Lymphangiectasia in Dogs
Certain diagnostic tests must be performed in dogs to diagnose lymphangiectasia and exclude other disease processes that may cause similar symptoms. A complete history, description of clinical signs, and thorough physical examination are all an important part of obtaining a diagnosis. In addition, the following tests are recommended to confirm a diagnosis: A complete blood count (CBC) may be within normal limits, but it often reveals a decreased lymphocyte count. A biochemical profile will help evaluate the kidney, liver, protein and electrolyte status. Hypoproteinemia is the hallmark of this disease. Hypocalcemia (low calcium) is often seen secondary to low protein levels. Additionally, hypocholesterolemia (decreased cholesterol) is common. A urinalysis is most often within normal limits and is helpful in ruling out protein loss associated with kidney disease. If there is any suspicion of kidney related protein loss, a urine protein:creatinine ratio should be evaluated. It is a simple test that can be performed on the urine. Fecal examinations should be performed to rule out parasitism. Chest and abdominal X-rays, although often within normal limits, may reveal fluid in the chest or abdominal cavity, or may be of benefit in ruling out other disorders. Abdominal ultrasound may be indicated if the previous diagnostics have been inconclusive. Although it cannot document lymphangiectasia, it helps to better evaluate the size, shape and integrity of the abdominal organs, and is especially helpful in evaluating for an intussusception or pancreatitis. It is a non-invasive procedure, but it may require transfer to a referral facility. An upper gastrointestinal (GI) barium series may be considered. It will help rule out foreign bodies and other causes of intestinal blockage. It also helps evaluate for intestinal ulcers and can assess intestinal wall thickness. A safe dye is given to the pet by mouth, and X-rays are taken as it travels through the GI tract. It is non-invasive and can usually be performed by your veterinarian, although it may necessitate transfer to a referral facility. Evaluating a portion of the stomach and small intestine with proper instrumentation by gastroduodenoscopy is often indicated. Biopsies can be obtained, without an abdominal incision, and submitted for microscopic evaluation. Endoscopic biopsies are often diagnostic in cases of lymphangiectasia. General anesthesia is necessary, although endoscopy is considered a relatively low risk procedure. It most often necessitates the expertise of a specialist and specialized instrumentation.
Your veterinarian may require additional tests to insure optimal medical care. These are selected on a case by case basis: Bile acids should be performed on those patients whose hypoproteinemia is potentially secondary to liver disease. They are paired blood tests obtained before and after a meal that evaluates liver function. The test is very safe and can be performed at your local veterinary hospital. Serum folate and cobalamin are blood tests that generally increase and decrease respectively, in those cases with small intestinal bacterial overgrowth (SIBO). Cytologic examination of feces and the rectal tissue may reveal histoplasmosis. Cardiac ultrasound may be performed in those patients where heart disease is felt to play a part in the hypoproteinemia. Laparotomy (abdominal surgery) allows surgical biopsy of intestines, lymph nodes and other organs to be obtained. Laparotomy may be the one test that confirms lymphangiectasia, as there is a characteristic appearance of the intestines and surrounding tissue, as well as the fact that obtaining a large, “full-thickness” biopsy may be necessary. There are moderate risks associated with doing surgery on hypoproteinemic animals, and should be performed only if absolutely necessary.
Appropriate therapy for dogs with lymphangiectasia varies according to the type of signs and severity of clinical illness. Depending on the severity of clinical signs and/or stage of disease, hospitalization may or may not be recommended. Patients who have severe vomiting and/or diarrhea, or hypoproteinemia and associated inappropriate fluid accumulation, are hospitalized for aggressive treatment and stabilization. Stable patients can be treated as outpatients as long as they are monitored closely for response to therapy. It is very important that all recommendations by your veterinarian are followed very closely, and any questions or concerns that arise during the treatment protocol are addressed immediately. Dietary management is an important part of therapy with lymphangiectasia. Low fat diets are recommended. Additionally, MCT oil (medium-chain triglycerides) is a source of calories that is well tolerated by patients with lymphangiectasia, and in those who are emaciated, help make up the calories missing in low fat diets. Diuretics that help remove excess fluid from the body may be indicated in some patients with lymphangiectasia where fluid accumulation in body cavities or tissues may be causing clinical problems. They should be used only as directed, and with caution. Oncotic agents (plasma, dextrans, hetastarch) help maintain normal fluid distribution in the body, and may be used in patients who are in immediate need of stabilization. Corticosteroids (anti-inflammatory drugs) may be of benefit in these patients. Other treatment options including surgical procedures may be indicated in those suffering from secondary lymphangiectasia. For example, a pericardectomy (removal of the covering of the heart) may be recommended in those with constrictive pericarditis.