From Pet Health Learning Center
Hemangiosarcoma is a very aggressive tumor of the cells of the blood vessels. Any diagnosis of hemangiosarcoma other than the skin form is very dangerous. These malignant tumors start in the blood cells. Due to that fact, they are filled with blood, which will transport the cancer cells to other parts of the body.
Dermal (skin) hemangiosarcoma
When a hemangiosarcoma is found on the skin, it can easily be removed surgically. This form of the disease is the most successfully cured form. This cancer is common to dogs with no hair, thin coats or white dogs. It can appear anywhere on the body including the abdomen. About one third of the cases will be metastatic and will enter other organs of the body.
This type of hemangiosarcoma is just under the skin. About sixty percent of these tumors will spread to other organs.
Visceral (spleen) hemangiosarcoma
This large visceral organ is not essential for life. It does however, serve an important role in the circulatory system. If the spleen enlarges too much it can break and blood will spill into the abdomen of the dog. Immediate surgery to remove the spleen is necessary to prevent the dog from totally hemorrhaging. Since the spleen is so vascular, spread to other organs will occur frequently.
It must also be noted that about twenty five percent of dogs who have spleen associated hemangiosarcoma also have one that is heart based.
Visceral (heart) hemangiosarcoma
This too can be a life threatening tumor. It can cause bleeding into the sac surrounding the heart, called the pericardium. When the sac fills it puts a lot of pressure on the heart and the heart can no longer function effectively.
Although it is known that sun exposure is the cause of dermal hemangiosarcoma, the cause of the other types has not been determined to any degree. It is felt however, that there may be a genetic link.
The location of the tumor will determine the appropriate treatment. Most treatment is temporary and the visceral type will need much more aggressive treatment than the other forms. The disease is seldom curable. The prognosis for long term recovery is very poor. The average life span of a dog that has been treated is approximately two months. Removing the spleen can extend their life by about nineteen to eighty three days. If the spleen has not ruptured the prognoses may be a little better. Less than 10 percent of the dogs whose spleen has ruptured as a result of hemangiosarcoma survive more than a year.
Hemangiosarcoma appears primarily in dogs. The age of the dog is usually middle to old age. Larger dogs are also more prone with the German Shepherd Dog being the most commonly affected. It appears most often in the spleen and other organs of the circulatory system. From there it can metastasize to the lungs, liver, heart and spleen.
Initially your veterinarian will check for Dog Anemia. The presence of pale gums and other mucous membrane is an indication of anemia. This would be followed by lab tests and x-rays. X-rays would determine the involvement of all of the organs that may be affected.