Leukemia is a progressive, malignant disease of the blood and blood-forming tissues of the body. Malignant diseases are those that tend to be invasive and to progressively worsen with time. They also are prone to metastasize, which means that the disease process moves from one organ or part of the body to others. In other words, malignant metastatic diseases usually spread from the area where they originate to one or more other places in the animal’s body. This makes them especially dangerous and life-threatening.
Leukemia is characterized by the out-of-control growth of white blood cells, which are also called “leukocytes.” The abnormal proliferation of leukocytes and their precursors takes place in a dog’s blood and bone marrow. White blood cells are critical components of an animal’s immune system. The main function of leukocytes is to protect the body against infection by bacterial, viral, fungal and other microorganisms. There are a number of different types of white blood cells (basophils, eosinophils, neutrophils, lymphocytes, monocytes and platelets). Each these cell types can give rise to a specific form of leukemia.
Leukemia can be acute or chronic. Acute leukemia is characterized by the uncontrolled proliferation of immature cancerous white blood cells in the bone marrow that normally would develop into mature white blood cells. These are called “precursors” of normal mature leukocytes. Chronic leukemia is characterized by the abnormal overgrowth of mature malignant white blood cells in the blood and bone marrow. As mentioned above, the precise classification of the leukemia depends upon the type of white blood cell whose growth has gone awry.
As with most other types of cancer, the causes of leukemia are not well-understood. Most leukemias in domestic dogs are thought to develop spontaneously after the dog is born. Exposure to radiation, infection by viruses and exposure to certain toxic chemical substances have all been suggested by various experts as being possible causes of or contributors to canine leukemia. However, there currently are no reliable, repeatable scientific studies that establish the contribution of these or
The symptoms of leukemia in dogs tend to be vague and non-specific. They often mimic the symptoms of many other systemic diseases - those that affect multiple organs or body systems – and usually involve general symptoms of weakness, fatigue and nausea, none of which can be pleasant for the affected animals.Owners of dogs with leukemia may notice one or more of the following clinical signs:Acute leukemia is more common in middle-aged dogs, averaging about
Many times, an abnormally high number of leukemic cells will be found in circulating blood on routine blood work, including a complete blood count and peripheral blood smears. The results of these tests can raise a high degree of suspicion that leukemia is responsible for the dog’s symptoms of unwellness. A serum biochemistry profile on a blood sample, and a urinalysis on a urine sample, can provide additional valuable information about the dog’s overall health.The
In most cases leukemia can be treated or managed, but rarely can it be cured. Treatment goals are to eradicate the cancerous leukocytes if possible, restore normal bone marrow production of red and white blood cells and their precursors, provide good supportive care to the dog and relieve the patient’s discomfort. Remission, which is the reduction or temporary cessation of the observable signs of an illness, is the ultimate therapeutic goal of treating leukemia. Veterinary