Reactive Tissue Lymphoma in Dogs

A lymphoma is basically a malignant tumor in the lymph tissue. The lymph system is a part of the immune response of the body. It circulates white blood cells and lymphocytes around the body as needed to fight off infections. In a dog, lymphocytes live for about 30 days before dying and being reabsorbed or eliminated from the body. In some types of lymphoma, these cells become more reactive and keep reproducing.

  1. Incidence of Lymphoma in Dogs

    • The tumors of the lymph tissue caused by reactive lymphocytes accounts for approximately 10 to 20 percent of cancers found in dogs. It can occur in any type of canine. However, some breeds of dogs, such as golden retrievers, are more prone to it.

    Symptoms

    • The symptoms of this cancer depend largely upon where the tumors are located. For example, If the tumor is in the gastrointestinal system, there may be vomiting, diarrhea, weight loss and lack of appetite. If they are in the lymph nodes, the main indicator may be swelling. Tumors of the mediastinal area (chest) are accompanied by possible shortness of breath. Since the symptoms vary so much it is important to discuss any health changes your pet exhibits with his veterinarian.

    Staging

    • Your vet will diagnose your dog through blood tests, biopsies, X-rays and/or ultrasounds. Once she has established a diagnosis of lymphoma, she will stage the cancer. Staging means she will determine the extent of the cancer's spread throughout your animal's body. The reason this is important is that it determines the possible treatment intervention.

    Stages

    • The stages of this disease range from Stage 1 through Stage V. Stage I means that only one lymph node or lymphoid tissue in a single organ is involved. Stages ll through IV are gradually more serious in progression until it reaches the last stage. Stage V signifies that there is involvement of the bone marrow.

    Prognosis

    • If a dog does get treatment in the form of chemotherapy, his life expectancy can be lengthened. Seventy-five percent of dogs attain complete remission with this treatment. However, the remission duration is usually only between six and 11 months. If the dog then receives more chemotherapy, 40 percent of them may achieve another remission period. This period will not be as long and very few achieve a third remission. Less than 20 percent of dogs live two years even with treatment.

    Potential

    • Immune modulation therapy may prove to be an addition to treatment for this type of lymphoma that can actually allow the cancer to be overcome in some animals. This is because chemotherapy and surgery remove the tumors, but the problem with the immune system that caused the reactive lymphocytes is still there. The immune modulators are veterinary grade formulas that trigger the immune recognition response and tell the body to reject the cancer cells.