Symptoms of Hemangiosarcoma in Dogs

Hemangiosarcoma, also referred to as angiosarcoma, is an aggressive malignant tumor that arises spontaneously from the cells that constitute the lining of small blood vessels. Hemangiosarcoma is initially presented with primary tumors in the spleen, liver, skin or soft tissue of the body. It is highly metastatic and capable of extensive spreading to the brain, lungs, heart, kidneys, muscles and bone. German shepherd dogs are believed to be predisposed to the condition. 

Cutaneous hemangiosarcomas occur in dogs that have short, pale coats. Repeated, damaging sun exposure causes a tumor that is initially benign but progresses to a hemangiosarcoma. Breeds that are believed to predisposed to this condition are Pit Bulls, Italian Greyhounds, Whippets and Dalmations.

Symptoms of Hemangiosarcoma in Dogs

Most dogs are not symptomatic until the advanced stages of the disease. Symptoms of hemangiosarcoma may vary depending upon the region of tumor growth. If the hemangiosarcoma occurs in the skin, muscles, or bone, a swelling may be visible beneath the skin. Visible symptoms of hemangiosarcoma are usually caused by rupture of the tumor and internal bleeding. Symptoms of this condition include: 

  • Depression
  • Weakness
  • Lethargy
  • Pain or sensitivity
  • Nosebleeds
  • Pale gums
  • Anemia
  • Difficulty breathing
  • Abdominal swelling
  • Seizures
  • Abnormal heart rhythm
  • Collapse

Disseminated intravascular coagulation, or DIC, is a blood disorder that is often associated with hemangiosarcoma tumors. Abnormal clotting within the blood vessels uses up the platelets and other clotting elements. A deficiency in these blood clotting elements can result in hemorrhaging. An increased clotting time may be an indication of DIC. Hemangiosarcoma can cause also cause severe hemorrhagic anemia from internal bleeding.

Diagnosis of Hemangiosarcoma in Dogs

A dog suspected of hemangiosarcoma will require a complete physical examination and testing. Laboratory blood work and urinalysis will be performed to determine the general health of the dog and possible damage to organs affected by the tumor. Because hemangiosarcoma is highly metastatic, radiographs (X-rays) or ultrasound will be recommended to determine if the cancer has spread to multiple body regions.

The tumor will need to be sampled or removed for biopsy in order to confirm diagnosis. Hemangiosarcomas bleed profusely if they are cut, so there is risk of this procedure causing severe internal bleeding . If multiple tumors are present, it may be difficult to determine which tumor is the primary hemangiosarcoma.

Treatment of Hemangiosarcoma in Dogs

Supportive care with fluid therapy will be required for dogs that have had internal bleeding due to the rupture of a tumor. In some cases a blood transfusion may be necessary, particularly if the dog has lost significant amounts of blood and will be undergoing surgery.

The exact course of treatment depends on the location of the tumor, the stage of the cancer and the overall condition of the dog. Complete surgical removal of the tumor(s)  is most effective in cases of hemangiosarcoma that involve the skin. Hemangiosarcoma that involves the internal organs requires aggressive treatment and is not often curative.

Hemangiosarcoma tumors are highly malignant and aggressive. Surgery is most effective if the tumors are local to one region of the body and have not metastasized. A dog recovering from surgical removal will require additional postoperative care. Chemotherapy is necessary after the removal of the tumor(s). Radiation therapy has been effective only in cases of hemangiosarcoma in the skin.