Lymphoma in Pets
Lymphoma is the most common cancer seen in small animal veterinary medicine, and can affect the lymphoid tissue of many possible organs. By far the most common area of involvement is the peripheral lymph nodes of the body, but lymphoma may also spread and involve internal areas, as well as even the skin. Causes of lymphoma are believed be genetic in origin; however, environmental factors, including overexposure and sensitivity to chemicals, pesticides, and even over-vaccination are all believed to play roles in increased development of lymphoma.
Clinical signs will vary depending upon the location of the cancer, but with peripheral lymphoma(the most common type), symptoms include firm swellings around the body, especially under the neck, as well as nonspecific symptoms of illness such as lethargy, loss of appetite, weight loss, vomiting/diarrhea and/or coughing or difficulty breathing. While tentative diagnosis of lymphoma is often made by needle aspiration of affected lymph nodes, definitive diagnosis usually requires an excisional tissue biopsy.
Treatment of lymphoma usually involves a sequential chemotherapy protocol, which will vary depending upon severity and location of the lymphoma. Prognosis for remission is usually very good, with some animals achieving cancer free periods for 1-2 years; however, the prognosis for cure is very guarded.