Lymphangiectasia in Dogs: A Guide

No pet owner ever wants to hear that their loving companion is suffering from a health condition, especially if it’s Lymphangiectasia. If your dog begins to display alarming symptoms, it’s highly advised to get them to a vet as soon as possible. The sooner your vet is able to catch Lymphangiectasia, the faster they can get him on a treatment plan and get him feeling back to normal. 

This article will highlight the signs, symptoms, and treatment methods of Lymphangiectasia in dogs. Once you as the owner are fully aware of this information, you’ll be able to better support and care for your four-legged friend. 

What is Lymphangiectasia?

Lymphangiectasia in dogs can easily be broken down into two simple parts: lymph and angiectasia. “Lymph” is defined as a fluid that is made up of proteins (serum albumin and globulin), salts, glucose, fats, water, and white blood cells. It is responsible for carrying, transporting, and circulating these key substances throughout the body within a network of lymphatic vessels. This critical movement requires regular muscle contraction, as well as healthy channels. “Angiectasia” is a medical condition characterized by the dilation or expansion of a blood or lymph vessel. Piecing these two words together, “lymphangiectasia” is a medical condition, which results in the dilation of lymph-carrying, lymphatic vessels. It is important to keep in mind that this definition is not all-encompassing; intestinal lymphangiectasia in dogs can also refer to restricted lymph circulation, which is due to obstruction, rather than dilation.

Why is it Important?

Lymphocytes, or lymph-containing white blood cells, work as a secondary line of defense for the immune system. When the body is fighting an infection, proper lymph circulation helps to ensure the immune system has additional white blood cells to fight the disease. Lymphocytes are especially important when a disease is advanced or resistant. In lymphangiectasia, the dilation of lymph vessels impairs the normal flow of lymph. If lymph cannot flow as expected, then lymphocytes will not be available to fight infection or reduce canine inflammation within the body. For this reason, lymphangiectasia is responsible for a critically compromised immune system.

In addition to fighting disease with lymphocytes, the lymphatic system is also responsible for maintaining fluid-based equilibrium. When lymphatic vessels dilate, however, they can break open and burst. A ruptured lymphatic vessel directly results in a variety of health abnormalities depending on the location of breakage. Whether in dogs or humans, this can happen in the intestines, abdomen, kidneys, heart, lungs, and skin. In such an event, excess lymph leaks out and the internal fluid balance is disrupted. This means that lymphocytes are accumulating in areas where they cannot be utilized. A ruptured lymphatic vessel is useless, as it cannot transport proteins, fats, and nutrients. This is compounded by the issue that these substances are now trapped under a thick layer of lymph fluid. For these two reasons, lymphangiectasia results in a dangerously reduced ability to circulate key nutrients and an increased susceptibility to disease. 

What Causes Lymphangiectasia in Dogs?

Lymphangiectasia can exist either as a primary or secondary condition. This classification is based on whether lymphangiectasia is the primary disease or secondary to a prevailing illness.

Primary Lymphangiectasia

 In its primary or congenital form, lymphangiectasia develops on its own. This is due to a preexisting developmental malformation of the lymphatic vessels that presents as one of the following forms:

    • Cholecystitis: This occurs when lymph fluid in the abdominal cavity.
    • Chylothorax: Here, lymph fluid builds up in the chest cavity.
    • Intestinal Lymphangiectasia: This condition, also known as Protein Losing Enteropathy (PLE) or Waldmann’s disease, results in excessive protein loss within the small intestine of the gastrointestinal (GI) tract.
    • Lymphedema: This is a physically apparent, widespread swelling, resulting from inadequate lymph drainage. 
    • Thoracic Duct Obstruction: The thoracic duct is the main vessel of the lymphatic system. Obstruction of this vessel results in a decreased ability to drain lymph within many important regions, including the chest and abdominal cavities. 
    • Widespread Malformation: This refers to an excessive occurrence of overly widened lymphatic vessels. 

Secondary Lymphangiectasia

In its secondary form, lymphangiectasia develops as a side effect of a more serious underlying illness. Secondary lymphangiectasia is commonly associated with one of the following diseases: 

    • Cancer: Secondary lymphangiectasia can result from the lymphatic obstruction of cancer-causing granulomas. Granulomas are excess masses of tissue caused by disease inflammation.
    • Constrictive Pericarditis: This condition results in an inflamed pericardium, which is the membrane enclosing the heart. Inflammation in this region causes increased pressure, known as central venous hypertension. This increased pressure impedes lymph circulation. 
    • Hepatic Veno-Occlusive Disease: In this disease, the veins surrounding the liver are obstructed. This obstruction also affects lymphatic vessels.
    • Right-Sided Heart Failure: An increase in central venous pressure causes a condition marked by cardiac lesions. This increased pressure secondarily causes lymphatic vessels to dilate and eventually burst.

Whether the diagnosis is primary or secondary lymphangiectasia, either case can be fatal if the body becomes unresponsive to medication. Instances of increased dilation or obstruction of lymph-carrying vessels result in a nutrient-rich fluid, which is either leaked or trapped in a body cavity. In the case of increased dilation, all of the lymph’s vital subcomponents are singularly absorbed in the location of the rupture, instead of being uniformly dispersed. This results in overall lower levels of lymphocytes, as well as fats and critical proteins, serum albumin and globulin. Collectively, serum albumin and globulin make up more than 90% of blood proteins. These are critically important for assisting in immune function, as well as transporting lipids, hormones, and ions.

Symptoms of Lymphangiectasia in Dogs

In dogs, secondary lymphangiectasia is more common than primary lymphangiectasia. If your dog is displaying symptoms associated with lymphangiectasia, there is a higher chance that another, oftentimes more serious disease is present concurrently. Once diagnosed, it is important for dog owners to understand that lymphangiectasia is rarely cured. After the symptoms subside, lymphangiectasia is most commonly in a state of remission. It can flare up again within the dog’s lifetime and early identification of the symptoms is crucial for successful intervention. 

  • Chronic Diarrhea: This is commonly defined as an increase in frequency, decrease in consistency, or elevated volume of feces over a period greater than three weeks.
  • Vomiting: Dogs that throw up multiple times within a 24-hour period should be promptly escorted to the vet. However, vomiting more than two times over a two-day period would also necessitate a visit to the vet.
  • Appetite Loss: Prolonged appetite loss is defined as no eating within a 48-hour period. Appetite loss in a shorter period can be due to a stressful situation or an upset stomach. If a dog does not eat for two days, seek immediate veterinary care.