Lymphoma is cancer that develops from a type of white blood cell called a lymphocyte. There are many forms of lymphoma of varying severity and occurring in almost any location in the body. The most common presentation in dogs is the multicentric form where many lymph nodes in the body are affected. Other forms include mediastinal (lymph nodes within the chest), cutaneous and gastrointestinal. If your dog has been diagnosed with multicentric lymphoma you may notice one or more lymph nodes are enlarged. Often the spleen, liver and internal lymph nodes are affected and in some cases the bone marrow.
The cause of lymphoma is generally unknown. Diagnosis is either by fine needle aspirate (very small needle biopsy) or by removing a larger piece of lymph node. We generally recommend that dogs with lymphoma are staged which is a series of tests including X-rays, ultrasound, blood and urine tests to determine the extent of the disease. This is not always essential but can help with treatment monitoring and provide prognostic information. In some patients bone marrow aspirate and biopsy will also be recommended.
When lymphoma is limited to one location in the body treatments such as surgery or radiation therapy may be recommended. It is more common, however, for lymphoma to occur in multiple locations and chemotherapy is generally recommended in these cases. This is because chemotherapy travels through the blood and can reach cancer cells throughout the body. The type of treatment offered and the outcome you can expect depends on the type of lymphoma. For the most common type of lymphoma (multicentric lymphoma) the average life expectancy with chemotherapy is approximately 1 year. The chemotherapy itself is generally very well tolerated. Please see our chemotherapy page here for more information. For further information tailored to your pet please ask your vet to submit a request for advice on your behalf.