Hemangiosarcoma of the Bone in Dogs


Overview of Canine Bone Hemangiosarcoma

Hemangiosarcoma is a type of cancer that arises from blood vessels and can occur almost anywhere in the body in dogs. It is a highly metastatic form of cancer, meaning it spreads readily to other tissues. Usually when hemangiosarcoma occurs in bone it is due to metastasis from another site, although rarely, it may actually arise in the bone; the bone is then referred to as the primary site.

This tumor affects the bone much more rarely than osteosarcoma, but when it occurs in bone it can sometimes be very difficult to distinguish from the osteosarcoma. The cause of hemangiosarcoma is largely unknown. In people this type of cancer has been linked to exposure to vinyl chloride, a chemical agent.

Hemangiosarcoma occurs most commonly in middle-aged to older, large breed dogs. It can affect the axial skeleton, which includes the bones of the spine, pelvis and skull, as well as the appendicular skeleton, which includes the arms and legs.

This is a lethal form of cancer in your pet. Average survival rate in animals with this type of cancer, even with treatment, is only months. In most cases, the tumor has already spread widely or will spread widely throughout the body, despite therapy and will continue to grow. When it primarily affects the bone, it can cause lameness and general debilitation of your pet during its development and progression.

What to Watch For

Signs of hemangiosarcoma of the bone in dogs may include: 

  • Lameness or pain, especially in the legs
  • Unexplained swelling of any bone
  • Broken bones without severe trauma
  • Bleeding

    Diagnosis of Hemangiosarcoma of the Bone in Dogs

    Diagnostic tests are necessary to diagnose the tumor and define the extent of disease. Tests that your veterinarian may wish to perform include:

  • Complete medical history and physical exam
  • Radiographs (X-rays) of the affected body part
  • Radiographs of the chest/lungs
  • Abdominal (belly) radiographs
  • Abdominal ultrasound
  • Cardiac (heart) ultrasound
  • Complete blood cell count (CBC)
  • Biochemistry profile
  • Urinalysis
  • Biopsy of the tumor

    Treatment of Hemangiosarcoma of the Bone in Dogs

    Treatment may include the following:

  • Surgical removal of the tumor, which usually involves removing the affected bone
  • Pain medications
  • Chemotherapy
  • Radiation therapy as an alternate form of palliative treatment for pain relief in very select cases
  • Home Care and Prevention

    Your veterinarian will most likely prescribe pain medication to ensure your pet’s comfort. These medications may be given prior to definitive diagnosis and/or after surgery. Medication will usually be in the form of pills or narcotic pain patches that are placed on the skin to release a constant level of medication across the skin.

    You should limit your dog’s activity to minimize pain and to prevent what is called a pathologic fracture, which is an abnormal breaking of the bone due to the cancer weakening the bone. Your pet should not run, jump or play during this time. You should watch your dog carefully and give assistance when he climbs stairs or when he gets in and out of the car.

    Have your veterinarian evaluate promptly any unexplained bump or lameness that develops. Lameness is more likely to be associated with arthritis or injury to ligaments and tendons than cancer, but it is worth having your dog evaluated nonetheless.

    If your dog does not improve with rest or anti-inflammatory drugs, radiographs of the affected part of the body may be indicated to exclude bone cancer as a cause of the lameness or pain.

    Hemangiosarcoma, like other cancers, is not currently preventable.

    In-depth Information on Hemangiosarcoma of the Bone in Dogs

    Hemangiosarcoma is a type of cancer that most commonly affects the spleen, liver and heart and typically causes bleeding from the ruptured tumor. Although it can arise in bone initially, this is rare. Most often when it occurs in bone, the tumor has spread there from another site in the body. Thus, if your dog is diagnosed with bone hemangiosarcoma it is vitally important that other more common sites of this tumor are excluded as the primary site.

    As with most forms of cancer, very little is known about what causes hemangiosarcoma to develop. It is a highly lethal form of cancer and thus the diagnosis and treatment should be prompt and aggressive.

    Related Symptoms or Diseases

  • Lameness. This is a general term used to describe pain or discomfort experienced when your pet moves normally or exercises minimally. Although your dog may develop lameness due to arthritis, ligament or tendon tears, or cartilage injury, lameness is also a cardinal sign of bone tumors. Therefore, any unexplained or chronic lameness in your pet warrants further investigation.
  • Pathologic fractures. If your dog experiences a fracture with minimal trauma, a pathologic fracture should be considered. Although fractures are most often a result of trauma, they can also occur in bones that have been weakened by cancer. Evaluating an X-ray may lead to the suspicion that the bone is abnormal; however, definite diagnosis of a tumor requires a biopsy. Pathologic fractures will not heal if fixed using standard techniques
  • Osteomyelitis. This is an infection in the bone and an uncommon condition that occurs as a result of infectious organisms such as bacteria or fungi getting into a bone. These organisms most commonly gain entrance to the bone through an open wound, open fracture or rarely through the blood (a blood borne infection). The appearance of osteomyelitis may be similar to some bone cancers because it often appears as a proliferative or fuzzy mass-like lesion on an X-ray. Differentiating these types of infection from bone cancer typically requires that a biopsy and a culture be performed.        
  • Bone infarction. This is a very rare condition in which a blood clot blocks the blood supply to a bone, resulting in death of the bone. On an X-ray this appears as a lytic lesion, which means there is loss of bone, and is similar to the appearance of bone cancer.
  • Metastatic tumors to bone. Occasionally a bone cancer can be due to the metastasis or spread of cancer from a primary cancer elsewhere, most commonly mammary gland cancer. These types of cancers tend to have a distinctively different appearance on X-rays than primary bone tumors. Although their radiographic appearance may alert your veterinarian to their presence, a biopsy is still required for a definitive diagnosis. It is important to distinguish tumors that have spread from other tissues to bone from those that arise in bone initially because the treatment differs. For metastatic tumors an attempt is made to determine the site of the primary cancer. If your pet is diagnosed with cancer, your veterinarian may wish to consult with an oncologist or cancer specialist to understand the specific behavior and treatment of the cancer.
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