Osteosarcoma

Overview:

Osteosarcoma is the most common bone tumor found in dogs and tends to affect the limbs of larger breed dogs.  The disease is aggressive and typically spreads to other parts of the body quickly.

Signs and Symptoms:

Dogs with osteosarcoma may experience swelling at the tumor site, lameness and joint or bone pain.  Some dogs may become lethargic and have little appetite.  In some cases, dogs will develop a mass or display painful inflammation around the site of the tumor.

Diagnostics:

Because osteosarcoma rapidly spreads to other parts of the body, we recommend the following diagnostic tests to determine which sites in the body may be affected:

  • Bone biopsy
  • Complete blood count (CBC)
  • Serum biochemistry panel
  • Urinalysis (U/A)
  • Lymph node evaluation
  • Radiographs

Treatment:

The goal with treatment is to surgically remove the tumor, delay the spread of the disease to other parts of the body and preserve quality of life for your pet.

In most dogs, amputation is necessary to remove the tumor.  Dogs tend to do quite well with amputation after an adjustment period. Systemic chemotherapy is recommended several weeks after surgery to delay metastasis. Four to six treatments are given at two to three week intervals.  When treatment is given for the first time, there may be some side effects which your oncologist will discuss with you.   We immediately treat any side effects and adjust the dosage for future treatments.  If no side effects are present after the first treatment, your dog should have no problems with subsequent treatments.

Most dogs experience a good quality of life with surgery alone.

In cases where systemic chemotherapy is not pursued, metronomic chemotherapy (chronic low-dose oral chemotherapy in conjunction with other medications ) may be considered to delay tumor growth.

Palliative radiation therapy may be an option when amputation is not.  Palliative radiation therapy consists of two consecutive twice-daily doses of radiation therapy to alleviate pain, inflammation and swelling.  If there is no disease or symptom progression, this treatment can be repeated a month later.