By: Dr. Jen Wallace

If your dog has been diagnosed with lymphoma, you may be feeling a range of emotions.  It is not uncommon to initially feel shocked, confused, and overwhelmed.   You may have many questions about the diagnosis and treatment starting with:

• What exactly is lymphoma?

• What is the prognosis and chance of recovery?

• What treatments are available?

• What will it all cost?

It is important to understand that lymphoma is one of the most common canine cancers, and treatments are available.  The diagnosis of lymphoma can be devastating but your canine companion could have many months to years of a good quality of life ahead.  

Typical clinical signs of lymphoma can range from increased thirst and urination, swollen lymph nodes in the neck or other parts of the body, weight loss, lethargy, vomiting, and diarrhea, to vague clinical signs such as your dog just seems a little “off.”  

So, you may be asking what exactly is lymphoma?  Lymphoma is a cancer of lymphocytes, a type of white blood cell important in the immune system.  Lymphocytes respond to infections and inflammation and help keep a dog healthy by fighting off foreign invaders, such as bacteria and viruses.  There are 2 types of lymphocytes:  B cells (which produce antibodies) and T cells (which can directly attack infections).  When these lymphocytes (either B or T cells) act independently of the normal immune response and checks and balances of the body and behave independently and aggressively they become a cancer, called lymphoma.  

B and T cell lymphomas can be further sub-categorized and can affect prognosis.  Advanced testing (blood or tissue samples) is generally needed to determine these other categories of B and T cell B-cell lymphomas.  B-cell lymphoma typically carries a better long-term prognosis than T-cell lymphoma.  However, some dogs with a specific type of T-cell cancer, called T-zone lymphoma can live for many years, and treatment is sometimes delayed until certain parameters are met or the dog begins to feel unwell.

Lymphoma typically occurs in tissues of the body with many lymphocytes, such as the lymph nodes and spleen.  However, it can occur in other areas of the body such as the chest, gastrointestinal tract, anal glands, and others.  Lymphoma can spread to the bone marrow and at these times be difficult to distinguish from leukemia (which starts in the bone marrow).  Some forms of lymphoma are very aggressive and even with treatment carry a poor prognosis with only a few months survival time.

Many general practice veterinarians can help determine the type (B or T cell) and stage (the extent of disease in the body).  This is done by performing diagnostics such as bloodwork (chemistry screen and CBC), chest radiographs, abdominal ultrasound, and specialized blood testing.  Aspirating enlarged lymph nodes can also lead to the diagnosis.  

So, what should you consider once you get the diagnosis that your dog has lymphoma?  If your primary care veterinarian has diagnosed your dog with lymphoma, ideally the type of lymphoma (B or T cell) should be determined to help guide treatment, prognosis, and if referral is needed quickly.  Staging of lymphoma may not be as important, especially if your dog is feeling well, as the treatment will generally be the same whether the cancer has spread or not.  If your dog is unwell and you are interested in giving your dog the best chance of remission a consultation with a board-certified oncologist as soon as possible is recommended.  If there will be a delay in getting the oncology consultation your primary care veterinarian may be able to speak with the local veterinary oncologist about starting some form of treatment while you are waiting for your appointment.  

Just as in human medicine a veterinary oncologist has advanced training in cancers and treatment.  A consultation with an oncologist can help you decide which treatment would be ideal based on your dog’s overall health and other medical conditions and your beliefs and wishes for your dog’s comfort and care. The oncologist will explain the various treatments, how they are administered, side effects, quality of life after treatments, duration of treatment, and how much this will cost.

Options such as palliative care (comfort care) can also be started if there is a delay in getting in to see the oncologist or if it is determined through consultation with your primary care veterinarian that this is the best course of action.  Medications such as glucocorticoids (steroids) are often used to treat lymphoma which can give your dog many months of a good quality of life.  Additionally, some dogs have confounding medical conditions that would make more aggressive treatment for lymphoma (such as IV or advanced oral chemotherapy) difficult.  The cost of treatment as well as your beliefs and wishes for your dog’s care also need to be discussed with your primary care veterinarian to determine if referral is the right choice for your dog.

Although it can be devastating to get the news your dog has been diagnosed with lymphoma there are treatments available to give your dog a prolonged survival time with a good quality of life.  Whether you choose IV chemotherapy with a chance for a prolonged remission or palliative care your canine companion can still live a comfortable and happy life for quite some time.