Hemangiosarcoma

What is Hemangiosarcoma?
Hemangiosarcoma is a malignant cancer that arises from the cells lining blood vessels. It most commonly arises as one or more tumors in the spleen, liver or heart, but can also be found as a primary tumor in the skin or bone.

How does my dog get Hemangiosarcoma?
The cause is unknown, although because it is found in some breeds more often than others, it may have a hereditary component.

How do I know if my dog has Hemangiosarcoma?
Very often the first sign is sudden weakness or collapse, with extremely pale gums. This occurs because the tumor bleeds, and the internal bleeding leads to hypovolemic shock. If  the bleeding does not stop, death can occur within minutes to hours. If the bleeding is from a tumor of the spleen or liver, the abdomen may be enlarged and filled with fluid. If it is from the heart (the right atrium), the blood can fill the pericardial sac (the lining around the heart) to the point that the heart can no longer beat.

Your veterinarian may be able to diagnose the condition through blood tests that would indicate recent bleeding episodes, and through radiographs that would indicate an enlarged or abnormally shaped spleen or heart silhouette. More definitive diagnosis is with ultrasound. If the abdomen is enlarged and fluid-filled, fluid drawn from it may have blood in it. Not all bleeding masses of the spleen are hemangiosarcoma; surgery with microscopic examination of the cells may be needed for a definite diagnosis.

Hemangiosarcoma of the skin appears as one or more firm, dark colored masses, usually on the limbs or underside; or as masses beneath the skin that appear to bruise and change size.  Skin biopsy is necessary for diagnosis. Hemangiosarcoma of the bone, which is not common, is seen as a swelling on a limb or rib bone.

What can I do about Hemangiosarcoma?
Except for hemangiosarcoma of the skin, in most cases the tumor has already been carried throughout the body by the bloodstream by the time it's diagnosed. Hemangiosarcoma of the heart has a poor prognosis; however,  removing blood that accumulates in the sac surrounding the heart may make the dog feel more comfortable and prolong his life somewhat.  Hemangiosarcoma of the spleen may be treated by removing the spleen; this, along with chemotherapy, may prolong life but is seldom curative because of metastatic spread, often to the liver and lungs. Hemangiosarcoma of the bone may require amputation, which may prolong life but is seldom curative.  Hemangiosarcoma of the skin may be treated with surgical excision, radiation and chemotherapy; it carries the best prognosis, especially if the tumors are on, rather than below, the skin surface. Unfortunately, except for skin hemangiosarcoma, survival times even with aggressive treatment average under a year.

Is there anything I can do to prevent my dog from getting Hemangiosarcoma?
At this time there is nothing you can do to prevent it. Research is ongoing for a DNA test to identify dogs at risk, and some work is even investigating a vaccination.

Are there certain breeds that get Hemangiosarcoma more often?
Large breeds in general are more likely to have hemangiosarcoma. German Shepherds, Golden Retrievers, Boxers, Great Danes, English Setters,  and pit bulls are among the breeds known to be affected more often, but almost any breed can develop it.