Dog lymphoma is a cancer of lymphocytes or white blood cells. It is a common type cancer that affects the lymphatic system in dogs.
Lymphoma symptoms in dogs
The specific symptoms are determined by the type of lymphoma in dogs. The most common type develops as lumps or swollen lymph glands on the neck, legs and shoulders. There is no pain or discomfort in the early stages. The enlarged lymph nodes are usually discovered by accident.
Other less common types of dog lymphoma affect the digestive tract, thymus glands or skin. The symptoms include vomiting, diarrhea, tiredness, breathing difficulty, lesions on skin and loss of appetite.
In the advanced stages of lymphoma, the general symptoms include weight loss, anemia, loss of appetite and weakness. As the lymph circulates throughout the body, other organs such as the spleen, liver and bone marrow can be affected. If left untreated, dogs with lymphoma have a life expectancy of 4-6 weeks following diagnosis.
Dog lymphoma treatment
Lymphoma in dogs can be treated with chemotherapy, prednisone therapy and blood stem cell transplant.
Chemotherapy
Chemotherapy is the main treatment for lymphoma in dogs. With this treatment, more than 80% of dogs will go into remission for at least 12 months. The numerous chemotherapy protocols are either multi-agent or single-agent.
Multi-agent chemotherapy involves a combination of drugs given orally or by injections. It is more effective than single-agent chemotherapy and produces longer remission. However, toxicity and the risk of unwanted side effects are higher as more drugs are used. This type of chemotherapy requires greater time commitment and bigger expense.
Single-agent chemotherapy protocol uses one chemotherapy drug. It is less toxic and costly than multi-agent chemotherapy. Any adverse side effect is attributed to the single drug, so a different drug can be used instead. As it is less effective than multi-agent chemotherapy, the first remission period is shorter, about 7 months.
The duration of remission and choice of chemotherapy protocols depend on the primary location of tumor, lymphoma stage, overall health of dog at the beginning of treatment and any changes in organ function. Most dogs respond to chemotherapy with minimal (if any) side effects. The common side effects are nausea, loss of appetite, diarrhea, vomiting, tiredness, hair loss and slow hair growth. Serious side effects are rare and only seen in 5-10% of dogs.
Prednisone therapy
Lymphoma in dogs can be treated with prednisone (corticosteroid) where chemotherapy is not recommended. Chemotherapy can be costly, so some pet owners choose prednisone therapy instead. Dogs given prednisone experience significant improvement in the short term and can lead a more comfortable life. Although sick, they eat, move and feel better while undergoing prednisone therapy.
Although prednisone therapy is inexpensive, it is not as effective as chemotherapy. Remission is short, about 2-3 months with possible side effects. Prednisone therapy should not be carried out prior to chemotherapy as it reduces the effectiveness of the latter.
Blood stem cell transplant
Stem cells are harvested from bone marrow. Only stem cells that are free from cancer are reintroduced into the dog after it has undergone total body radiation to kill of remaining cancer cells in the body.
Although this treatment raises the survival rate significantly, it is very expensive.
Your vet can advise you on the most suitable lymphoma treatment for your dog. You want to consider the costs, time commitment, life span and your dog’s comfort in deciding whether to proceed with treatment.