Overview of Lymphosarcoma of the Canine Kidney
Lymphosarcoma is a general term for malignant cancers of lymphoid tissues, which may affect multiple organs, including the kidneys. Lymphosarcoma is a very common type of cancer in both dogs and cats, but the form affecting the kidney is much more common in cats than dogs.
Lymphosarcoma is caused by cancerous lymphocytes, a type of white blood cell. Middle aged to older dogs and cats are affected.
Lymphosarcoma is ultimately a fatal disease, but it often goes into remission with appropriate therapy. Many animals with renal lymphosarcoma often develop renal failure.
What to Watch For
Signs of lymphosarcoma of the kidney in dogs may include:
Increased thirst and urination
Animals with multi-organ involvement may show other signs of illness such as behavior changes, lack of coordination, especially of the hind legs in cats, extreme hind limb weakness, and yellow discoloration of the skin (jaundice).
Diagnosis of Renal Lymphosarcoma in Dogs
History and physical exam. The most common physical exam finding in dogs is enlargement of both kidneys. This will often be appreciable by abdominal palpation.
Complete blood count. A CBC evaluates the red and white blood cells, as well as the platelets. Affected patients may be anemic (low red blood cell count), and may have evidence of abnormal white blood cells in circulation, as well as platelet abnormalities.
Biochemical profile. This is important to evaluate kidney function and other organ function. It may help indicate which organs are involved in the disease process.
Urinalysis. Analysis of the urine provides further information with respect to kidney function.
Chest and abdominal x-rays. Imaging studies of the body cavities allows identification of the extent of cancer involvement and provides objective determination of kidney size.
Abdominal ultrasound. This is a non-invasive method to obtain more information regarding kidney architecture. It also allows examination of abdominal lymph nodes, which are often enlarged in cases of lymphosarcoma.
Fine needle renal aspirate or kidney biopsy. Lymphosarcoma may usually be diagnosed by a fine needle aspirate of affected kidneys, in which fluid is withdrawn by a needle. This is a relatively non-invasive procedure, which can be done with minimal or no sedation. If the aspirate sample is non-diagnostic, a tissue biopsy of the kidney will need to be performed.
Bone marrow aspirate. Obtaining a sample of the bone marrow is necessary if lymphosarcoma is suspected, as it allows determination of the presence of tumor cells in the bone marrow. This is part of what is called the staging process of the diagnostic work-up.
Treatment of Renal Lymphosarcoma in Dogs
The treatment of choice for lymphosarcoma is chemotherapy. This type of cancer is quite responsive to chemotherapy drugs.
Chemotherapy involves weekly visits to your veterinarian and often requires treatment by a veterinary internist or oncologist.
Home Care and Prevention
Give all medications as prescribed by your veterinarian. Some chemotherapy drugs are given orally, at home. Monitoring for response to therapy as well as side effects from the chemotherapy is important. Vomiting, diarrhea, inappetence, and lethargy are signs to watch for at home.
There are no measures to be taken to prevent development of renal lymphosarcoma.