Fluid Retention and Tissue Swelling Due to Collection of Lymph in Dogs

Similar to the human body, the lymphatic system is like the body’s cleansing system in dogs. It contains the lymph nodes and lymph vessels and contains lymphocytes, which are white blood cells that help guard the body against any infections or inflammations. When the blood circulates, this complex process includes the collection and transfer of a clear fluid, called lymph. Lymph is taken from the body’s tissues and then returned back into the blood via lymphatic vessels. When there is an abnormality in the lymph flow, the fluid collects and swelling occurs. Lymphedema is the common term for this disorder.

This can be the result of lymph nodes (that filter the fluid) or lymph vessels developing atypically. It can also be the result of an underlying condition that has caused an abnormality in the lymphatic system. Underlying disorders can be tumors, surgery, inflammation, or any other disorder that causes the lymph vessels to become blocked, thus inhibiting proper flow.

Lymphedema is the swelling of various tissues in the dog’s body due to fluid retention within the tissues. This is caused by an abnormality in the lymphatic system.

When the lymph fluid is obstructed, it collects in the bodily tissues. As this occurs, swelling that is noticeable on the outside of the body can concern any dog owner. If your dog has any of the following symptoms, you should make an appointment with your veterinarian. Symptoms include:

• Swelling of the feet and legs
• Swelling of the abdomen 
• Swelling of the chest
• Any outer extremities becoming swollen (tail or ears)
• Lameness
• Malaise
• Lethargy
• Skin discoloration

Types

There are different types of disorders similar to or secondary to lymphedema that your veterinarian will check for during the examination and testing. A few of these types may also be considered a differential diagnosis that the veterinarian will have to rule out before making a definitive diagnosis of this disorder. Types include:

• Congenital lymphedema
• Primary lymphedema
• Intestinal lymphedema
• Intestinal lymphangiectasia
• Inflammatory edema
• Arteriovenous fistula
• Neoplastic infiltration
• Hypoproteinemia
• Hepatic failure

Studies show that this disorder could be inherited in some breeds. Other studies show that this disorder is completely idiopathic (primary lymphedema). Secondary lymphedema causes or triggers may include:

• Congenital aplasia
• Hypoplasia
• Hyperplasia
• Neoplasia
• Radiation therapy to the affected area
• Trauma

If your dog has swelling, make an appointment with your veterinarian. The veterinarian will ask questions about his symptoms and any underlying conditions. The medical professional will do a complete examination and then recommend a urinalysis and blood tests. 

The veterinarian may gently press on the swollen area to see how it responds to this; he will be looking for “spongy” feeling tissue and he will be looking for the area which is pressed to keep an indention for a short time before returning to normal.

If your veterinarian suspects your dog has lymphedema, either primary or secondary, he will take a sample of the swollen tissue and test it to be sure it is lymph fluid in the affected tissue. The veterinarian may also choose to perform a lymphangiography, which is a dye test, similar to a heart catheterization, where an imaging source can allow the veterinarian to watch the flow of the colored dye throughout the lymphatic system.

Many dogs can become affected with lymphedema and usually the cases subside on their own. Lymphedema does not always have a serious effect on the dog’s health, depending on the dog and the severity of the condition. It also depends on whether the swelling is caused by a primary or secondary source. Treatment may include:

Compression

The affected tissue areas can be wrapped in a compression bandage to help reduce the swelling. The veterinarian will demonstrate how to wrap the areas and will show you the amount of pressure that needs to be applied. Heating pads on a low setting and lymphatic massage may also be options to help your pet.

Change in Diet

Since lymphedema can only be treated rather than completely cured, the veterinarian may recommend a special diet for your companion. A diet that is healthy can boost the immune system to allow the lymphatic system to do its job more effectively.

Medication

Medication to reduce the swelling or an antibiotic may also be prescribed by your veterinarian. Both may be used to help calm the swelling.

Mild and localized lymphedema has a good prognosis, but this does depend on the cause and if there are any underlying disorders. If your dog has been diagnosed with generalized lymphedema, the prognosis is considered “guarded” and must be watched to see if your dog will go into remission.

Since there are many possible causes of secondary lymphedema, recovery depends on the other condition and how severe your dog’s lymphatic system has been affected. Your medical professional will give you advice and instructions on how to care for your dog during this time.