Acute Lymphocytic Leukemia in Dogs

Acute Lymphocytic Leukemia (ALL) is a very serious disease of the blood. It is a kind of cancer that requires aggressive chemotherapy. It is similar to Chronic Lymphocytic Leukemia (CLL), but ALL spreads quickly and will kill a dog much faster than CLL.

  1. The Facts

    • Leukemia is any disease in which the body makes too many white blood cells. Bone marrow makes white blood cells, and in leukemia sufferers, the bone marrow makes so many white blood cells that it can't make enough of the other kinds of blood cells that are also needed. In ALL, these white blood cells originate in lymphatic tissue (lymph nodes, spleen and bone marrow) and are malignant. Because they are in the blood, they infiltrate all the organs in the body.

    Symptoms

    • Symptoms for ALL can include the sudden onset of fever, listlessness, poor appetite, weight loss and diarrhea. ALL can also cause swelling in organs because of the infusion of cancer cells. The most common organ to swell is the spleen. Lymph nodes may also swell up, but this is usually pretty mild.

    Treatment

    • The only treatment that has been known to cause remission of ALL is chemotherapy. Even though aggressive chemotherapy drugs are used, only about 30 percent of dogs will go into remission. Dogs that do not receive chemotherapy will usually die within a couple of weeks. Other treatments that are used to combat the effects of the disease include blood transfusions, which will help with anemia that will set in; antibiotics, which will help a weakened immune system; and intravenous fluid therapy, which will keep the dog from being dehydrated and will keep the blood electrolyte levels balanced.

    Diagnosis

    • Proper diagnosis is important so that the right treatment can be given as soon as possible to give the dog the best chance at achieving remission. If a dog exhibits symptoms of ALL, it should be given a blood test to get a white blood cell count. Normal blood usually has less than 3,500 white blood cells per microliter. If the count is over 20,000, this usually means ALL or CLL. A more definitive test for lymphocytic leukemia involves extracting some cells from the bone marrow to check for cancer cells. If there are cancer cells, then the white blood cells need to be examined under a microscope to determine if it is ALL or CLL.

    Causes and Prevention

    • There are no confirmed causes for ALL, so there is no way to prevent it. Radiation exposure and benzene have been known to cause ALL in humans, so it is thought that these could be causes of ALL in dogs as well, but this has not been confirmed. Some viruses have been known to cause leukemia and other lymphocytic cancers in cats, birds and cattle, but no "leukemia virus" has been discovered for dogs. German Shepherds and other large breeds of dogs are more predisposed to getting ALL.