Hemangiosarcoma is a malignant cancer of the cells that form blood vessels. Because these tumors start in blood vessels, they are frequently filled with blood. Consequently, when a blood-filled tumor ruptures, it can cause problems with internal or external bleeding. Hemangiosarcoma is considered to be a very aggressive tumor and can spread rapidly to other organs. Despite intensive treatment, many animals with hemangiosarcoma succumb a few months after diagnosis.

Hemangiosarcoma is more common in dogs than in cats. It usually occurs in middle-aged to older dogs 9 to 11 years of age, and German shepherds appear to be predisposed to developing this cancer.

The most common primary location of this cancer in dogs is the spleen. Other primary locations include the heart, liver, skin, and bone; however, it can start in any location where blood vessels are present. These tumors usually spread to the lungs, liver, spleen and heart.

Diagnosis and Treatment Notes:

  • Hemangiosarcoma is generally diagnosed by biopsy of a mass. However, bloodwork, x-rays of the chest and abdomen and ultrasound of the heart and abdomen can lead to a suspicion of hemangiosarcoma.
  • Treatment depends on the severity of the disease, your individual pet, and your veterinarian. Anemic animals should receive a blood transfusion. For animals with blood accumulating around the heart, a tap should be performed to remove some of the blood. Surgery is recommended to try to remove any abdominal tumor. In some cases, radiation or chemotherapy may be attempted. ¬†Discuss treatment details when your pet is diagnosed with this condition.


What to Watch for*:

  • Anemia, weakness and collapse
  • Pale or white gums
  • Difficulty breathing
  • Exercise intolerance
  • Fluid build-up of the abdomen

*Please notify us if you notice any of the above signs or if you have any questions!