Leukemia

A lab came in today because he had been losing a lot of weight over a short period of time with no change to his diet or daily exercise.  Blood was taken and tests were run.  The CBC showed that the lab's white blood cell count was through the roof!  Doctors worried that he could have leukemia. 

Leukemia is a cancer of the blood that is caused by a genetic mutation that alters the structure of the bone marrow, making it able to produce these cancerous blood cells rather than healthy blood cells.

There are two types of leukemia that can affect dogs: lymphocytic (originates in the lymph nodes) and myelogenus (originates in the bone marrow).  The most common type of leukemia is lymphocytic leukemia.  It is characterized by an over abundance of white blood cells in the blood stream.  White blood cells are a part of the immune system; they are sent into the blood to fight inflammation and infection.  However mutated leukemia white blood cells are cancerous and take over the blood stream, and leaving very little room for the red blood cells and platelets to circulate.

Once the type of leukemia has been classified, it can be broken down into another subgroup based on whether it is a sudden onset (acute leukemia) or long term (chronic leukemia).   Acute leukemia can be extremely dangerous because the sudden increase in cancerous blood cells that hinders the production of healthy blood cells, which can affect a dog's life.  Chronic leukemia, although still very unhealthy, is not as malignant as acute leukemia because it is a gradual build up of cancerous cells.  Chronic leukemia is more commonly found in elderly dogs. 

www.nlm.gov

To check our preliminary diagnoses of Leukemia, the doctor ordered bone marrow aspirates and a biopsy.  Aspirates are usually done first.  The doctor sticks a needle into the bone marrow and collects liquid bone marrow and smears it onto slides to be examined under a microscope.  To get the biopsy, the doctor uses a thin biopsy needle and sticks it into the bone.  The needle has a sharp and curved edge so when it is twisted, it cuts a cylinder of bone marrow out of the bone. 

Causes for leukemia are unknown and although there is no simple cure, there are ways to treat it.  Chemotherapy is one good option because it stops the growth of these cancerous blood cells.  In patients with chronic leukemia, chemotherapy can be a smart and hopeful decision.  With patient with acute leukemia, only a small percentage of dogs can go into remission, even with very rigorous chemotherapy.  A dog's immune system is usually extremely weak from the disease and chemotherapy only weakens the immune system more and makes the patient more proned to other diseases.  Ususally transfusions will also need to occur because the disease and the chemotherapy can make them extremely anemic.