Osteosarcoma is a type of cancer that typically arises in the bones of the limbs. Less commonly, it may occur in the bones of the spine, pelvis, and skull. Osteosarcoma is the most common type of bone cancer, and it is estimated to occur in more than 8,000 dogs in the United States each year. Osteosarcoma occurs very rarely in cats.

The cause of osteosarcoma is largely unknown and is most common in large-breed dogs (over 50 pounds). Most dogs are 6 years of age or older when they develop this tumor; however, it does occur in animals as young as two years of age.

This is a highly metastatic, meaning it spreads to other parts of the body, and life-threatening form of cancer and usually causes lameness and general debilitation of your pet during its development and progression. Average life expectancy in dogs that receive treatment in the form of amputation, or surgical removal of the leg, and chemotherapy is 10 to 12 months. Without treatment, life expectancy is usually two to four months.

Diagnosis and Treatment Notes:

  • Osteosarcoma is generally diagnosed by x-rays of the affected leg, chest x-rays and bloodwork. A biopsy of the tumor and/or a bone scan may be beneficial.
  • Treatment depends on the severity of the disease, your individual pet, and your veterinarian. Surgical removal of the tumor, usually limb amputation, is usually recommended. Chemotherapy and radiation therapy may also be suggested. Limb-sparing surgery is an option that you may want to consider. Discuss treatment details when your pet is diagnosed with this condition.


What to Watch for*:

  • Lameness
  • Pain of any of the bones
  • Broken bone with minimal trauma
  • Swelling of a leg


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