National Canine Lymphoma Month raises awareness for dog owners
Monday, November 17, 2025
Media Contact: Kinsey Reed | Communications Coordinator | 405-744-6740 | kinsey.reed@okstate.edu
Dog lovers and the veterinary community observe Nov. 7 as National Canine Lymphoma Awareness Day. This day highlights the cancer journey of dogs and pet parents in the fight not only to survive lymphoma but to thrive with the disease.
Lymphoma (also called lymphosarcoma) is a cancer that affects white blood cells, known as lymphocytes, and the lymphatic system. Both are essential members of your dog’s immune defense network and include lymph nodes, spleen, and bone marrow. Lymphocytes become cancerous and grow uncontrollably, causing local and systemwide disease.
Because the immune system is made up of a diverse network of cells and organs, lymphoma can have very different clinical presentations. The most common clinical sign is enlarged lymph nodes — firm, rubbery lumps felt underneath the jaw, in front of the shoulders, or behind the knees. Dogs affected by lymphoma can behave normally, or they can be ill with signs of decreased energy, decreased appetite, vomiting, diarrhea, coughing, increased thirst, increased urination and difficulty breathing.
When your veterinarian suspects lymphoma, a needle sample (aspirate or biopsy) from enlarged lymph nodes or organs is necessary to determine if abnormal cells are present. Bloodwork and diagnostic imaging (radiographs, ultrasound) are important to determine the extent of the disease — this is called staging. Additional specialized testing can help determine the type of cancerous white blood cells. All the diagnostic information gathered can help determine prognosis and treatment choices.
Although it is not curable, lymphoma is one of the most treatable cancers in dogs. The most common treatment for lymphoma is chemotherapy, which is the use of medication to stop the growth of cancer cells. Although the thought of chemotherapy can evoke fear in many pet parents, most dogs tolerate the side effects well and can live a normal life during therapy. If side effects do occur, treatments can be adjusted to meet an individual dog’s needs.
For most, a good quality of life can be expected during chemotherapy. Remission time, which is the period when the cancer is undetectable during treatment, varies depending on the patient and the type of cancer. Some dogs may experience cancer-free years, while others may have only a few months in remission. Unfortunately, without treatment, lymphoma progresses quickly and a quality life is short-lived, with some dogs surviving only weeks.
The diagnosis of cancer is scary and heartbreaking — it is a diagnosis no one wants to hear. While every dog’s journey is unique, the focus should always be on maintaining a good quality of life, ensuring your pet feels comfortable, loved, and able to enjoy each day.
Written by: Dr. Lara Sypniewski, clinical associate professor in small animal primary care and Henthorne Clinical Professorship in Small Animal Medicine.