Lymphoma or lymphosarcoma is the cancer of lymphocytes which are a type of white blood cells and are involved in the immune system. In lymphosarcoma, lymphocytes grow uncontrollably and take over any tissue they attack. The symptoms of the disease vary depending upon the part of the body which is affected. In the case of general lymphoma, the pet experiences the symptoms like enlarged lymph nodes, lethargy, weight loss, and loss of appetite. In certain cases, the condition may be asymptomatic and disease is found incidentally. Diagnosis requires blood work, radiographs of the chest/abdomen, and ultrasound of the abdomen to identify the affected regions of the body. A lymph node aspirate or biopsy sample is the best way to determine the exact type of cell involved, prognosis, and the extent of cancer. Although lymphoma is the most common form of cancer to occur but also most responsive to chemotherapy. After the diagnosis, your vet will discuss the available treatment options and possible outcomes of the treatment. Radiotherapy and chemotherapy are the common options available. Prognosis depends on the condition of your pet at the time of diagnosis, response to therapy, feline leukemia (FeLV) status, and the extent of metastasis.