Dog’s lymph nodes are a part of their immune system. Their name probably sounds scary, but they are a normal part of healthy dogs’ bodies.
Have you ever noticed their neck getting bigger on the sides? Did your Google search tell you it must be cancer?
There are many other causes of enlarged lymph nodes in dogs, and it’s not always the worst possible scenario.
Let’s dig deeper into the leading causes of lymphadenitis besides cancer itself.
What are Lymph Nodes in Dogs?
Your dog’s immune system involves the lymphatic system. It consists of lymph nodes and a system of lymph vessels known as lymphatics, which run alongside your dog’s normal blood vessels.
The lymph system in your dog’s body serves several essential functions, including transporting white blood cells, metabolic waste products from tissues and cells, and aiding in producing disease-fighting antibodies.
Lymph nodes are tiny bean-shaped organs that house immune cells. When viruses or bacteria invade your dog’s body, or if your dog has a disease that causes an immune response, the lymph nodes swell to fight the invader.
Lymphadenopathy or lymphadenomegaly refers to swollen lymph nodes. “Palpable” lymph nodes are those that can be felt through the skin. Below, we are gonna mention a few words about lymph nodes:
- Submandibular: enlarged submandibular lymph nodes appear in the area just beneath the jaw where it meets the neck, sometimes caused by a dental disease
- Pre-scapular lymph nodes are located beneath the submandibular lymph nodes in the front of the shoulders.
- Axillary lymph nodes are located in the dog’s “armpit,” or where the front legs meet the chest
- Inguinal lymph nodes are located on the dog’s underside where the back legs meet the abdomen (groin)
- Popliteal: Located just behind the stifles (or “knees”) of the back legs
When your veterinarian appears to be petting your dog during a physical exam, he is feeling for irregularities in the lymph nodes and finds out if there are any swollen dog’s lymph nodes.
In a healthy dog, the only palpable lymph nodes are submandibular and popliteal.
Other Symptoms of Swollen Lymph Nodes
Swollen lymph nodes can sometimes be detected at home by pet parents. If you’re petting your dog and notice a new or unusual bump in one of the above areas, it could be swollen lymph nodes.
Swollen lymph nodes in dogs can cause clinical signs at times, but the swelling is often palpable when touched beneath the jaw or around the shoulders.
Enlarged lymph nodes in one of the legs or near the armpit is also a possible scenario. This can result in pain or limping.
Swelling may also occur near the groin, making defecation difficult for your dogs. It may also result in nausea, vomiting, and regurgitation.
If multiple lymph nodes are severely swollen, dogs may have difficulty eating or breathing because of the physical closing of the trachea and esophagus.
However, if your dog’s lymph nodes are noticeably enlarged, you should be on the lookout for symptoms such as:
- Poor appetite
- Coughing
- Vomiting
- Lethargy
- Fever
- Abdomen enlargement
The appearance of these symptoms shows the cause of the lymph node enlargement has spread inside the bloodstream and is causing generalized inflammation. This infection or malignant process will create an immune response, which will cause hyperproduction of immune cells and mediators.
The immune response will develop generalized symptoms such as the ones mentioned above. This is an alarm to pay a visit to your vet immediately and seek treatment for your pet.
Common Causes Of Lymphadenitis
Swollen lymph nodes in pups can be caused by several conditions. Most of the time, these aren’t serious and don’t require much treatment because dogs will fight off the infection on their own.
As we mentioned before, lymph nodes are the most apparent when battling infections.
These infections can arise from the internal organs or from within the lymph node itself, which is known as lymphadenitis.
This is mostly due to an increased rate of lymphocyte (white blood cell) trafficking into the nodes from the blood, which exceeds the rate of nodal outflow.
The immunological reaction between antigen and lymphocyte results in cellular proliferation and lymph node hypertrophy.
Secondary lymph node enlargement may occur as a result of antigen-specific T and B cell activation and proliferation (clonal expansion).
Some causes of swollen dog lymph nodes, on the other hand, are pretty serious, even life-threatening. That is why it is best to have a veterinarian diagnose the condition and prescribe treatment for the lymph node enlargement.
Some of the potential causes of lymphadenopathy in dogs include:
- Allergic reactions to parasites
- Autoimmune disorder
- Bacterial or fungal infection
- Leukemia
- Infection of the bone marrow
- Tick-borne diseases
- Reactive hyperplasia
- Cancer
- Asthma
- Anxiety
Lymphoma In Dogs
The term “lymphoma” refers to a wide range of malignancies in dogs that are caused by white blood cells called lymphocytes. Lymphocytes are generally part of the immune resistance that protects the body from infection.
It’s a relatively common cancer and can vary from a developing lymphoma (sometimes triggered by chronic inflammation) to an advanced lymphoma – that is only treatable with chemotherapy and radiotherapy.
Although lymphoma can affect practically any organ in the body, it most usually affects immune-system organs such as the dog’s lymph nodes, spleen, and bone marrow.
The most frequent type of lymphoma in dogs is multicentric lymphoma, which first manifests in the lymph nodes and then spreads among the other immune organs.
Firm, swollen, painless lymph nodes are dogs’ most typical early symptoms of multicentric lymphoma. Under your dog’s skin, a lymph node impacted by cancer will feel like a hard, rubbery bump.
The mandibular lymphatic vessels (under the jaw) and popliteal lymph nodes are the lymph nodes on a dog’s body that are the easiest to find (behind the knee).
Other frequent signs and symptoms include anorexia, fatigue, weight loss, edema (swelling of the face or legs), and on occasion, increased thirst and changes in the urine.
Primary Lymphedema
Unlike the typical secondary “general edema,” lymphedema is an autonomous, chronic clinical disease with a propensity to progress. It results from one of several underlying disorders, such as heart insufficiency, venous insufficiency, or renal insufficiency.
It is based on an inadequate lymphatic drainage system, which can be acquired (secondary lymphedema) or congenital (primary lymphedema).
The lymphatic vessels’ transit capacity is insufficient to handle the resulting lymphatic loads and swallowing. The lymphatic drainage system may have primary (congenital) or secondary impairment at different levels.
As a result, the smallest lymph vessels (lymphatic capillaries, lymphatic sinuses), pre collectors, collect cells, lymphatic trunks, or lymph nodes are all affected.
Additionally, the interstitium sustains long-term inflammatory damage and requires long-term treatment and follow-ups.
Dog Breeds Prone to Swollen Lymph Nodes
There are no breeds that are predisposed to swollen lymph nodes. Some breeds, however, are more prone to infections that produce lymph node enlargement.
Other breeds, such as Golden retrievers, Boxers, Dobermans, and Rottweilers, are predisposed to lymphosarcoma (cancer of the lymphatic vessels).
Toy breeds (such as Yorkies, Poodles, and Dachshunds) are prone to dental illness and frequently have swollen submandibular lymph nodes when their teeth and gums are affected.
Most of the time, your dog’s lifestyle is a stronger predictor of susceptibility to diseases that cause swollen lymph nodes.
A hunting dog, for example, is more prone than an indoor dog to get tick-borne infections such as Lyme disease and ehrlichiosis, as well as fungal, bacterial, or parasite disorders that cause swollen lymph nodes.
Diagnosis of Underlying Causes
Your veterinarian will begin by completing a thorough physical examination and gathering information about your dog. When giving your dog’s history, make sure to note any recent injuries or interactions with insects and snakes.
Your veterinarian will almost certainly do a battery of diagnostic tests (such as blood tests) to rule out frequent causes of tissue swelling, like as injury, heart disease, or infection.
A total blood count, testing for tick-borne illnesses and heartworm disease, evaluations of liver, kidney, and pancreas functions, and electrolyte tests to screen for dehydration.
Also, a tiny needle aspirate of the afflicted area of the adjacent lymph node will most likely be performed for a definitive diagnosis.
A fine-needle aspiration (FNA) is a procedure that involves extracting cells from a lymphatic mass using a needle and transferring the fine needle aspirate to a slide for examination under a microscope.
It is non-invasive and can be performed on the same day as your dog’s initial assessment. If the fine needle aspirate does not indicate any malignant or inflammatory cells, x-rays or an ultrasound may be advised to determine the cause of the swollen dog’s lymph nodes.
Lymphangiography may be considered if primary lymphedema is suspected. In this treatment, dye is injected beneath the swollen areas, and the flow is monitored using video x-rays (fluoroscopy) to identify areas of poor circulation.
However, the most precise diagnosis can be made with a lymph node biopsy, where the cancerous cells or benign cells are taken from the lymph node for microscopic analysis.
Swollen Lymph Nodes Treatment Options
Lymphedema treatment options depend on the cause. Possible treatments include:
Antibiotic therapy
Antibiotic treatment is carried out in case of infection of the lymphatic system of bacterial origin. It destroys the bacteria or reduces their number, so the swollen lymph nodes shrink.
Amoxicillin and erythromycin are the most used antibiotics for cases of a swollen lymph nodes.
Non-steroidal anti-inflammatory drugs (NSAIDs)
This group includes drugs such as ibuprofen, ketonal, diclofenac, and others. They reduce the dog’s pain and elevated body temperature caused by a swollen lymph node. They also work to calm the inflammatory process and normalize the level of lymphocytes and other inflammatory cells and mediators.
Steroids
They are used for moderately severe inflammatory diseases. They work to reduce the inflammatory process and remove the swelling.
Special care should be taken in the dosage because these drugs in very high doses cause severe immune system suppression. It can lead to the development of harmful infections of all organs and a fatal outcome.
Wraps and massages
The lymphatic system’s circulation can be improved by simply massaging the affected part of the body. Long-lasting pressure compresses further reduce the accumulation of lymph fluid in the lymph nodes.
Surgery
If all these treatments do not give results, surgery should be resorted to. Lymph node dissection is a procedure that requires complete anesthesia of the dog and a long recovery period.
The medical name of this procedure is lymphadenectomy – it means the extraction of the entire lymph node and exploration of the other lymph nodes in the surrounding tissues.
This is usually done in young or middle-aged dogs. Whereas in older dogs with damaged cells, lymphadenectomy is not always successful.
Chemotherapy
Chemotherapy is the most effective treatment for the majority of canine lymphoma forms. Radiation therapy and surgery are great treatment options for dogs with canine lymphoma. However, dogs that don’t have cancer, should get other treatment.
On the other side, canines with multicentric lymphoma require several treatment regimens.
Follow-Up
Long-term lymphedema may make the animal more susceptible to infections in the enlarged area. The damaged area eventually experiences fibrosis and scarring.
Complications may appear if the bandages are not applied and changed properly when bandaging for a lengthy time.
So frequent check-ups must be done in a vet’s clinic, and they must include lab work, as well as other additional tests.
Prognosis
Generalized types of congenital lymphedema are frequently fatal. Puppies often pass away soon after birth, especially English bulldogs with severe lymphedema. In cases when only the back legs are affected, the edema may get better or go away.
The underlying etiology determines the prognosis for secondary lymphedema, which is often irreversible. Even in the absence of therapy, focal lymphedema may be well tolerated.
Lymphoma diagnosis differs according to the type, size, and metastases. The survival rate in dogs is around 70%.
FAQ:
To Sum Up
Dog’s lymphatic system plays the main role in the immune response and white blood cell creation.
Enlarged lymph nodes in dogs can result from an allergic reaction to parasites and bacterial or viral infection. Autoimmune diseases can also result in lymphadenopathy, as well as leukemia and tick-borne diseases.
If you notice swollen lymph nodes in your dog, you should pay a visit to your vet to reveal what is causing the swelling and seek proper treatment.
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*photo by tonodiaz – depositphotos