National Canine Lymphoma Awareness Day: How to Spot Signs in Your Dog

November 7th marks National Canine Lymphoma Awareness Day. Founded in 2015 by respected agility dog trainer Terry Simons, this annual event seeks to raise awareness for one of the most common types of malignant cancer in dogs. Terry’s beloved dog, Reveille, was diagnosed with this devastating illness in 2011, and despite valiant efforts, she passed away about a year later. In response, he founded the Canine Lymphoma Education and Research (CLEAR) Foundation to provide education and guidance to pet owners whose dogs have lymphoma.

In honor of this important event, we’d like to share some information about canine lymphoma. As your dog’s veterinarian, we are committed to providing the education you need to give your dog a happy, healthy life. Read on to learn more.

What is Canine Lymphoma?

Canine lymphoma, also known as lymphosarcoma, is one of the most common types of cancer in dogs. The term “lymphoma” refers to several types of cancer derived from lymphocytes — one of the five types of white blood cells.

Some of the most common types of lymphomas in dogs are:

  • Multicentric lymphoma
  • Extranodal lymphoma
  • Alimentary lymphoma
  • Mediastinal lymphoma

In most cases, the disease originates in organs that act as part of the immune system, such as the lymph nodes, bone marrow, or spleen. However, it can also occur in other areas, such as the respiratory system, gastrointestinal tract, or skin.

Between 20 and 24% of all tumor cases in dogs are canine lymphoma, and the disease is most common in older pets. Certain dog breeds are more likely to develop this type of tumor than others.

The breeds in which canine lymphoma is most common include:

  • Scottish Terriers
  • Basset Hounds
  • Bulldogs
  • Saint Bernards
  • Bull Mastiffs
  • Boxers

The breeds least predisposed to this illness include Dachshunds and Pomeranians, but any dog breed can develop lymphoma.

While feline lymphoma is closely linked to the Feline Leukemia Virus (FelV), scientists have not yet determined what causes canine lymphoma. Some experts hypothesize that genetics are to blame, while others believe certain immunodeficiencies and retroviruses could cause the disease. Research into learning more about lymphoma in dogs and its causes is ongoing.

Symptoms of Canine Lymphoma

There are more than 30 types of canine lymphoma, all of which vary in behavior. The symptoms of this disease vary, too, and are often similar to the symptoms of other illnesses. This is one of the many reasons it is vital to seek veterinary treatment when you notice any problem with your dog. While a symptom may have a minor cause, it could also signify something much more sinister, like cancer.

Some of the most common symptoms of lymphoma in dogs include:

  • Swollen lymph nodes
  • Lethargy
  • Weakness
  • Fever
  • Dehydration
  • Loss of appetite
  • Vomiting
  • Diarrhea
  • Weight loss
  • Difficulty breathing
  • Increased thirst and urination
  • Swelling of the front legs or face
  • Raised nodules or lesions
  • Blindness
  • Seizures
  • Pain

How We Diagnose Lymphoma in Dogs

If we suspect that your dog may have cancer, we’ll recommend various tests. Most often, cytology or biopsy is the best way to diagnose lymphoma. During cytology, we insert a fine needle into an organ to extract a small tissue sample. For a biopsy, we’ll surgically remove a small piece of the organ we suspect may be affected by cancer. In some cases, we remove an entire lymph node. While we strive to remove as little tissue as possible to ensure our patients’ comfort and safety, larger samples improve the chances of reaching an accurate diagnosis of lymphoma.

Once we have confirmed your dog has lymphoma, we may recommend staging tests to determine how much the disease has spread throughout your pet’s body. Determining how much the cancer has spread helps us assess your dog’s prognosis. Staging tests also help us determine whether your dog has other health problems or conditions that could affect their overall prognosis or treatment options.

Some of the most common staging tests we use for lymphoma include:

We may also recommend a fine needle aspirate to confirm whether the lymphoma is present in any organs that appear abnormal on a sonogram. We’ll always take the time to explain the tests we recommend and address any questions or concerns you may have. And of course, we will keep you up-to-date on our findings.

Treating Canine Lymphoma

Chemotherapy is the most effective treatment for canine lymphoma. As your dog’s veterinarian, we may refer your dog to a veterinary oncology specialist who will develop a treatment protocol that offers the best chance of a favorable outcome. We may also recommend radiation therapy or surgery based on your dog’s unique case. In many cases, lymphoma goes into remission with treatment. And unlike in humans, the side effects of chemo are usually not severe in dogs. Most dogs do not lose their fur while undergoing chemotherapy, either.

Unfortunately, chemotherapy only cures lymphoma in rare instances. Most dogs with this disease will experience a relapse at some point after going into remission. A second remission is possible, but it is usually shorter than the first one. This is because the cancer cells become increasingly resistant to chemotherapy as time passes. Eventually, most cases become resistant to chemo, and the patient succumbs to the disease or is humanely euthanized.

What to Do If You Think Your Dog Could Have Lymphoma

When it comes to something as precious as your pet’s health, it is always best to err on the side of caution. No pet parent wants to think about their dog having lymphoma (or other types of cancer). If you have any reason to suspect that your canine companion could be seriously ill, though, we encourage you to contact us right away. Any symptoms that persist for more than a day or two warrant bringing your dog in for an exam. Call now to schedule your dog’s appointment with our skilled team.


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