Helpful Information on Canine Lymphoma (Cancer in Dogs)

Canine lymphoma is one of the most common forms of cancer in dogs, so it’s helpful for pet owners to understand the risk factors and symptoms, as well as how it is diagnosed and treated. However, lymphoma is a complex disease with many different forms and is often talked or written about with detailed medical terminology, which can make it hard for owners to follow the conversation – particularly when they are dealing with the emotional stress of what to do for their beloved pet with lymphoma.

If you’re interested in learning more about lymphoma cancer in dogs, there are some terms you’ll want to know. For example, a “malignant” tumor is one that’s capable of spreading to other areas and organs of the body, as opposed to a “benign” tumor, which does not spread. A “lymphocyte” is a type of white blood cell that fights infection, but that can be “mutated” or changed in a way that makes it cancerous. Lymphocytes are part of the “lymphatic system” – a network of tissues and organs that help rid the body of toxins, waste, and other unwanted materials. Lymphoma is considered a “systemic” disease – as lymphocytes travel readily throughout the lymphatic system in their infection-fighting role – meaning that a cancerous version of the cell can affect many areas of the body.

The cause of canine lymphoma is “multifactorial,” which means that many elements (genetic and environmental) can trigger the disease. As a result, there are many different “subtypes” or forms of lymphoma, and each subtype is thought to behave differently. The most common forms of canine lymphoma are similar to those described as “non-Hodgkin’s lymphomas” in humans—cancers that originate in the lymphatic system. Thus, canine lymphoma often can be treated in a similar manner as humans with “chemotherapy agents” (i.e. drugs that kill cancer cells).

Most lymphomas fall into one of four categories:

  1. “multicentric” (present in lymph tissue/nodes in multiple places)
  2. “alimentary” (present in the digestive system)
  3. “mediastinal” (present in the chest)
  4. “extranodal” (present outside of the lymph nodes)

Terms like “cytology,” “histology” and “immunophenotype” have to do with identifying and categorizing the cancer cells involved and determining the form of lymphoma, while “staging” refers to determining if – and how far – the cancer has spread, while a “prognosis” is an assessment of the outcome of the disease.

diagram of peripheral lymph nodes

Recommended Reading on Canine Lymphoma

With these terms in mind, we recommend checking out this enlightening article in the Whole Dog Journal: Canine Lymphoma: Risk Factors, Symptoms, Diagnosis, and Treatment. It goes into great detail on the disease and can help you be better informed if your dog has developed the disease. We strongly encourage you to speak with your local veterinarian or veterinary oncology specialist to better understand any of the topics in this article or clarify any questions you may have. Lymphoma is one of the few cancers in dogs that can have long remission times, so it is important for you to be as informed as possible when dealing with this devastating, but often treatable form of cancer in dogs.


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  1. My sweet love 12 yo black lab was diagnosed with lymphoma last night. Is Tanovea available? If so, will our new oncologist know it? If not available, why not?

    • Hi, Kathy-
      We are so sorry to hear about your dog’s diagnosis and wish them the best. We encourage you to speak with your veterinarian regarding the best course of treatment for your dog. You can find out more information about our current supply shortage on the website here:

      Thank you.

  2. When will Tanovea become available for new patients? My dog has Lymphoma.

    • Please check your email as I just responded to you directly.

  3. My dog had very large lymph nodes which have since gone down. He is on prednisone and pain medication. He pants very loud at times and licks himself constantly. I do not know what to do – whether I should put him down now if he is in a lot of pain or I can wait for a while.

    • Hi, Patsy-

      We would recommend speaking with your veterinarian as soon as possible to see the best possible options for your pet. We wish you the best at this difficult time.