Issue Description Leukemia is a cancer of the blood and causes a
large increase of white blood cells (leukocytes) either in the
circulation or in the bone marrow. Leukemia can come from bone marrow
or from lymph node cells.
Types Of Canine Leukemia Acute Lymphoid Leukemia (ALL) develops rapidly.
Symptoms include loss of appetite, swelling of the lymph nodes,
panting, pica (obsessive eating of non-food items such as clay, dirt,
etc.), fever, bleeding, vomiting, pale gums, anxiousness. Infections
will occur and are triggered by not having enough healthy, fully
functional white blood cells. That as a result can cause rapid death
if not treated immediately.
Contrary to humans, where acute
leukemia is one of the most common childhood cancers, this cancer is
mostly reported in mature dogs, not puppies or young animals.
Treatment for acute leukemia is similar to chronic leukemia but
success rates are very poor. Most dogs live only a very short time
after the disease has been diagnosed.
Chronic leukemia (CLL
or CML) develops over time. The number of white blood cells increases
less rapidly and the disease gets worse slowly over time. Again, due
to the increased number of white blood cells the body cannot be
protected properly from viruses or infections and the immune system
will be suppressed. In addition a failure of the bone marrow and
infiltration of cancer cells into organs will occur.
Chronic eosinophilic leukemia is a disease in which too many
eosinophils (a type of white blood cell) are found in the bone marrow,
blood, and other tissues. Chronic eosinophilic leukemia may stay the
same for many years, or it may progress quickly to acute leukemia.
The hypereosinophilic syndrome is a disease process characterized by a
persistently elevated eosinophil count in
the blood for at least six months without any recognizable cause after
a careful workup, with evidence of involvement of either the heart,
nervous system, or bone marrow. Although HS has no certain aetiology,
evidence suggests a link with chronic eosinophilic leukemia as it
shows similar characteristics and genetic defects.
Symptoms Damage to the bone marrow, by way of displacing
the normal bone marrow cells with higher numbers of immature white
blood cells, results in a lack of blood platelets, which are important
in the blood clotting process. This means patients with leukemia may
become bruised, bleed excessively, or develop pinprick bleeds
White blood cells, which are involved in
fighting pathogens, may be suppressed or dysfunctional. This could
cause the patient's immune system to be unable to fight off a simple
infection or to start attacking other body cells. Because leukemia
prevents the immune system from working normally, some patients
experience frequent infection, ranging from infected tonsils, sores in
the mouth, or diarrhea to life-threatening pneumonia or opportunistic
Finally, the red blood cell deficiency leads to
anemia, which may cause dyspnea and pallor.
experience other symptoms. These symptoms might include feeling sick,
such as having fevers, chills, night sweats and other flu-like
symptoms, or feeling fatigued. Some patients experience nausea or a
feeling of fullness due to an enlarged liver and spleen; this can
result in unintentional weight loss. If the leukemic cells invade the
central nervous system, then neurological symptoms (notably headaches)
All symptoms associated with leukemia can be
attributed to other diseases. Consequently, leukemia is always
diagnosed through medical tests.
The word leukemia, which
means 'white blood', is derived from the disease's namesake high white
blood cell counts that most leukemia patients have before treatment.
The high number of white blood cells are apparent when a blood sample
is viewed under a microscope. Frequently, these extra white blood
cells are immature or dysfunctional. The excessive number of cells can
also interfere with the level of other cells, causing a harmful
imbalance in the blood count.
Some leukemia patients do not
have high white blood cell counts visible during a regular blood
count. This less-common condition is called aleukemia. The bone marrow
still contains cancerous white blood cells which disrupt the normal
production of blood cells. However, the leukemic cells are staying in
the marrow instead of entering the bloodstream, where they would be
visible in a blood test. For an aleukemic patient, the white blood
cell counts in the bloodstream can be normal or low. Aleukemia can
occur in any of the four major types of leukemia, and is particularly
common in hairy cell leukemia.
Diagnosis Leukemia is diagnosed by examination of the
bone marrow and blood.
Treatment Treatments are done to reduce the number of
white blood cells and lead normally to a temporary remission. In most
cases the number of white cells will increase again, and as soon as
the critical number is reached, treatments can be repeated. This
remission - re-treatment can be done many times. Unfortunately, sooner
or later, depending on individual cases, the chronic leukemia will
turn into acute leukemia.
Some dogs have been known to live
several months or even years until the acute leukemia takes over.
Research Significant research into the causes,
diagnosis, treatment, and prognosis of leukemia is being done.
Hundreds of clinical trials are being planned or conducted at any
given time. Studies may focus on effective means of treatment, better
ways of treating the disease, improving the quality of life for
patients, or appropriate care in remission or after cures.