Hemangiosarcoma, classed as
one of the soft-tissue sarcomas, hemangiosarcoma is a malignant
tumor of the lining of the blood vessels. It can occur at any site in
the body but 50% of these tumors are found in the spleen. (German
shepherds and Northern breeds statistically are at higher risk for this
cancer.) Hemangiosarcomas have been found in the heart,
lung, liver, spleen, and skin.
Typically, there are few symptoms until the cancer has progressed; a few
dogs die of “unknown causes,” without exhibiting symptoms. So you see,
the importance of necropsies and biopsies cannot be overstated.
This is a cancer where surgery and/or chemotherapy may offer more time,
as opposed to malignant histiocytosis where there are no treatment
Common clinical signs are episodic weakness, often to the point of
collapse, increased respiration, heart irregularities, and abdominal
swelling. When the tumor is in the spleen it can grow very large and is
usually felt during a physical examination. Hemangiosarcoma is often
accompanied by a blood disorder that causes inappropriate clotting
inside the blood vessels. X-rays and fluid aspiration can aid in
diagnosis of this aggressive cancer. Treatment includes surgery and
chemotherapy but the prognosis is very poor with this malignancy.
In cases of cardiac hemangiosarcoma, the tumor is located
in the heart, resulting in fluid around the heart, which is often the
only sign of the cancer. These cases are usually inoperable. Cutaneous
hemangiosarcoma occurs when the tumor invades the skin. With early
diagnosis and surgical removal, there is a good possibility for a
Cancers of this type occurring in humans have been linked
to radiation and chemicals. Animal studies have demonstrated links to
these cancers from biocides, some gasoline
additives, and chemicals used in the manufacture of plastics. The
most important known carcinogens for malignant hemangiosarcoma are:
Arsenicals like those found in pesticides, especially Chromated Copper
Arsenate (CCA) which is a chemical mixture consisting of ions of three
elements (arsenic, chromium and copper). CCA is injected into wood by a
high pressure process saturates wood products with the chemical. CCA
protects wood from dry rot, fungi, molds, termites, and other pests, and
CCA-treated wood is most commonly used for decks, walkways, fences,
gazebos, boat docks, and playground equipment. Other common uses of CCA-treated
wood include highway noise barriers, sign posts, utility posts, and
retaining walls. Effective, December 31, 2003, the EPA no longer allows
the affected CCA products to be used to treat wood intended for most
residential settings. Of course, those homes with CCA treated wood
remain a source of contamination. Arsenic is readily absorbed through
ingestion and inhalation.
Thorium dioxide used in high temperature ceramics, gas mantles, nuclear
fuel, flame spraying, crucibles, medicines, nonsilica optical glass, in
thoriated tungsten filaments, and as a catalyst.
which is present in cigarettes, chewing tobacco, and snuff.
Vinyl chloride a colorless organic gas
with a sweet odor, used in the manufacture of numerous products in
building and construction, automotive industry, electrical wire
insulation and cables, piping, industrial and household equipment,
medical supplies. Vinyl chloride is depended upon heavily by the
rubber, paper, and glass industries.
radiation has also been linked to soft-tissue sarcomas. In the early
1900s, when scientists were just discovering the potential uses of
radiation to treat disease, little was known about safe dosage levels
and precise methods of delivery. At that time, radiation was used to
treat a variety of medical problems. Later, researchers found that high
doses of radiation caused soft tissue sarcomas in some patients. Because
of this risk, radiation treatment for cancer is now planned to ensure
that the maximum dosage of radiation is delivered to diseased tissue
while surrounding healthy tissue is protected as much as possible.
© 2001 by
Bouyet: Excerpted from “Akita-Treasure of Japan-Volume II” by Barbara
Bouyet, Magnum Publishing.
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