Lymphoma in Cats

Lymphoma or lymphosarcoma is the most common type of cancer in cats, which is characterized by abnormal proliferation of malignant lymphocytes. The incidence of this cancer have been observed to be higher in cats than dogs. It can affect any cat, irrespective of their breed and sex. Generally, lymphoma is classified into two categories, high grade or lymphoblastic, and low-grade or lymphocytic. Based on the location, the cancer is categorized as, multicentric, mediastinal, gastrointestinal and extranodal lymphoma. Multicentric form of the cancer involves multiple lymph nodes and can affect multiple organs. Mediastinal lymphoma usually affects the lymph nodes, located in the thorax and thymus, while the extranodal form involves the central nervous system, skin, heart, kidneys and the eyes. On the other hand, gastrointestinal form of the condition affects the digestive tract. Intestinal lymphoma is one of the most common types of feline lymphoma.

Causes of Feline Lymphoma

This condition have been found to be associated with infection caused by feline leukemia virus. This virus is usually associated with the multicentric form of the disease. Earlier, feline leukemia virus was the main factor, responsible for the higher incidence of lymphoma in younger cats. However, with the growing use of vaccination, the incidence of this cancer in young cats has reduced significantly. Earlier, feline leukemia virus accounted for about 70% of the total cases. But, nowadays, only 20% of the total cases of feline lymphoma have been found to have an association with feline leukemia virus. Another virus, known as feline immunodeficiency virus can also increase the risk for lymphoma. Other factors that are thought to play an important role in the development of this cancer include, genetic predisposition as well as exposure to carcinogens like, cigarette smoke.

Feline Lymphoma Symptoms

Lymphoma can affect multiple organs including, liver, spleen, central nervous system, kidney and bone marrow. The symptoms of the condition therefore, depends to a great extent on the particular organ or organs affected. Nevertheless, the most common symptoms observed in feline lymphoma are

• Loss of appetite
• Progressive weight loss
• Diarrhea and vomiting in cats
• Lethargy in cats
• Increased thirst and urination (when the kidneys are affected)
• Breathing difficulty
• Poor coat condition
• Pale mucous membrane
• Anemia

Diagnosis and Treatment for Feline Lymphoma

Diagnosis begins with physical examinations, that reveals swollen lymph nodes or swelling of the gastrointestinal tract. Other tests that are carried out for the accurate diagnosis of the condition are, complete blood cell count test, chemistry panel, X-rays and ultrasound of the internal organs and fine needle aspiration or biopsy.

Chemotherapy is the most common treatment. The chemotherapy drugs that are generally used for treatment include, cyclophosphamide, prednisone, doxorubicin and vincristine. When the tumor is localized, It can be treated with radiation therapy as well. Similarly, surgery and laser treatment can also be carried out, if the tumor is localized to a particular site only. Immunotherapy is another treatment option available for treating this cancer.

The prognosis of the condition depends on the early treatment, as well as the location of the tumor. It also depends on the type of the lymphoma. Usually, the low-grade lymphoma has better prognosis than the high grade lymphoma. The prognosis has been usually found to be good for the younger cats. But, cats with feline leukemia virus and feline immunodeficiency virus have shown poor response to cancer treatment with low survival rate.

In general, cats with lymphoma can survive up to 4 to 6 months with proper treatment, while in a few instances, some cats can experience a remission of period of 2 or more years. However, the most important part is the early diagnosis of this condition, which sometimes can become a bit difficult, as its symptoms are not very specific. So, owners should remain vigilant against the disease and report any kind of cat health problem, especially unexplained weight loss, loss of appetite and persistent diarrhea and vomiting to the veterinarian, in order to rule out the possibility of serious conditions like, lymphoma or lymphosarcoma. Also important is to protect your cats from feline leukemia and feline immunodeficiency virus with appropriate vaccination.