Learn the Facts About Lymphoma in Cats
Lymphoma in cats is defined as a type of cancer that originates in the lymphocyte cells, a type of white blood cell that plays a key role in maintaining the immune system and fighting off diseases. The lymph system is found in blood and tissues throughout the body, a network of vessels and nodes through which foreign proteins and disease organisms are circulated. Lymphocytes have a number of roles in the immune system, acting to recognize antigens, produce antibodies, destroying cells that could cause damage.
Lymphoma is found to be responsible for 90 percent of blood cancers, accounting for 33 percent of all tumors in cats. The incidence of feline lymphoma ranges from 41 to 200 cases per 100,000 cats of any age, from 4 months to 19 years. There are 4 different types of lymphoma in cats: Mediastinal form, Alimentary form, Multicentric form and Solitary form. Alimentary (intestinal) lymphoma is the most common form of lymphoma in cats.
General Signs and Symptoms
Depression and extreme lethargy
Marked weight loss
Noticeable loss of appetite
Swollen lymph nodes (such as under the arms, in jaw or in groin region)
Diagnosing Lymphoma in Cats
Your veterinarian will request a full history of your cat’s health and onset of symptoms. A blood test will be performed which may reveal anemia, the presence of an abnormally high number of lymphoblasts in the peripheral blood, a condition called lymphoblastosis. How does this happen? Lymphoblasts are immature cells which differentiate to form mature lymphocytes which are normally present in bone marrow. In the event the lymphoblasts rapidly increase in numbers, they may migrate to the peripheral blood, resulting in the abnormal condition of lymphoblastosis.
A urinalysis may reveal abnormally high levels of pigment bilirubin and proteins in the urine. Affected cats are also tested for the feline leukemia virus (FeLV) and Feline Immunodeficiency Virus (FIV) which increases the likelihood that they could develop feline lymphoma. Your vet will also use diagnostic imaging to locate the tumor (s), conducting X-rays of various body regions, more specifically the region that seems to be affected. To conclusively diagnose leukemia, a biopsy of the bone marrow will be taken.
Lymphoma is systematic in cats and the preferred treatment is chemotherapy. Cyclophosphamide, vincristine and prednisolone (CVP protocol) form the basis of any treatment protocol for GI lymphoma in cats. Common side effects of this chemo cocktail include vomiting, diarrhea and anorexia, however are manageable with supporting treatment. CBC should be monitored weekly for the first several treatments due to the possibility of severe myelosuppression. Surgery is also indicated at times to remove a partial or complete intestinal obstruction or perforation, then followed by chemotherapy, after a post-surgical 10-14 day delay.
Survival Rate for Cats Diagnosed with Lymphoma
Unfortunately, there is no cure for this disease. The survival rate for a cat being treated with steroids is 6 months, compared to a cat not being treated with a life expectancy of 4-6 weeks. The survival rate increases if a cat is able to achieve remission, as well as if a cat is clinically healthy when the diagnosis of lymphoma is confirmed.