What is osteosarcoma?

Osteosarcoma is an aggressive bone cancer, with 80% occurring in the limbs and spreading readily to other organs (i.e., metastasis). As osteosarcoma grows, the cancer becomes progressively more painful, destroys and weakens the bone, and can cause a fracture. The mouth and spine can also be tumor sites. Large-breed neutered males are more predisposed to osteosarcoma, with a 20-fold increase in certain breeds. Early osteosarcoma signs can mimic arthritis, osteomyelitis, or fungal diseases.

What are common osteosarcoma signs in dogs?

Early signs include:

• Mild lameness

• Unwillingness to jump or use stairs

• Panting

• Depression

Intermediate to advanced signs include: 

• Severe lameness

• Muscle wasting

• Swelling on the affected leg

• Decreased appetite

• Coughing

• Trouble breathing

How is osteosarcoma managed in dogs? 

Osteosarcoma management involves chemotherapy protocols to treat the cancer, and multiple options to address the pain. Limb amputation or limb-sparing surgery to remove the tumor offer the best pain management. If surgery is not an option, palliative radiation therapy and intravenous treatments for pain are often recommended. Oral analgesics also are important for pain management. Dogs with osteosarcoma need regular veterinary visits to monitor their status and prognosis. Discussing a personalized management plan with your veterinarian, and a veterinary oncologist, is important for the best outcome for your dog.

What is the prognosis for dogs with osteosarcoma?

The prognosis for osteosarcoma is highly variable, depending on the chosen treatment. Without treatment, survival time is between one and three months. With radiation and chemotherapy, the median survival time is seven months. With the surgery and chemotherapy combination, the survival rate is approximately one year, with 25% of dogs alive at two years.  

Management tips for dogs with osteosarcoma    

At-home needs include:

• Easy access to food and water, and a comfortable location

• Consistency with prescription medications 

• Ramps and safety gates

• Mobility aids (e.g., sling or harness)  

• Preventing pressure sores

• Monitoring appetite, weight, drinking, urination, and energy level

In a crisis situation:

Contact your veterinarian immediately if your dog is having significant medication side effects, swelling or drainage at the surgery site, or difficulty walking; collapses; or is unable to walk at all, or vocalizing in pain.

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