Lymphoma in Dogs

Lymphoma is a cancer that affects the immune cells of the lymphatic system. These cells may be located in the lymph nodes, spleen, liver, bone marrow, and blood. Enlarged, painless lymph nodes (or lumps) are often noted by owners. The pet may also have non-specific signs of not feeling well such as a decreased appetite or activity level.

Lymphoma is one of the most treatable cancers in pets and is not a death sentence! Dogs can have a good and long quality of life with minimal to no side effects with appropriate treatment. Treatments are given on an outpatient basis with pets returning home in the afternoon so minimal time is spent at the veterinary hospital.

To diagnose lymphoma, a needle sample or biopsy of the abnormal area (i.e. lymph node) is submitted to the pathologist. Other tests are required to stage the lymphoma and determine the general health of your pet. These include blood and urine samples, radiographs, and a bone marrow sample. This will provide the information needed to determine if your pet is a good candidate for a successful treatment.

Dogs diagnosed with lymphoma that are not treated have an expected lifespan of only 1-3 months. With successful treatment, a lifespan of 1-2 years is expected. If and when the lymphoma in your pet returns (i.e. comes out of remission), chemotherapy can often be restarted and control the disease a second, and third time for additional quality time with your pet.

Lymphoma is treated with the most up to date and aggressive chemotherapy protocols allowing quality of life for your pet. Options include:

• A 25 week (i.e. 6 month) protocol which includes 5 drugs (Prednisone, L-asparaginase, Vincristine, Cyclophosphamide, and Doxorubicin). These drugs are given as pills, injections and IV drips. The treatments are given weekly for 8 weeks, then every 2 weeks for 8 treatments. This protocol provides the longest remission and highest rate of remission in dogs diagnosed with lymphoma. Side effects are uncommon and usually mild and of short duration.
• A 6 month protocol using Prednisone and Doxorubicin, a drug given as an IV drip, administered every 3 weeks for 6 treatments. Side effects are uncommon and mild. This protocol provides the second longest remission lengths and remission rates.
• The COP protocol includes Prednisone, Cyclophosphamide, and Vincristine, a combination of pills and injections and provides the third longest remissions rate and length. Four weekly treatments are given followed by monthly injections, while giving pills at home for 1 year. This is the least expensive protocol and side effects are again uncommon.
• Prednisone can be given alone at home (pills) in order to make the pet feel better for 1-3 months. Prednisone alone does not provide a durable remission or lengthen survival.

No matter which protocol is chosen to best treat your pet, we know that unfortunately the lymphoma will return (i.e. relapse) in the future. At that time, chemotherapy can be restarted or a number of other protocols that include different chemotherapy agents and schedules (rescue protocols) can be used (CCNU, D-MAC, Mitoxantrone).

Lymphoma is a disease that responds well to chemotherapy, but success is best achieved when treatment is started early and aggressively. Dr. Bravo will review and guide you through the process of selecting the best treatment for you and your pet.