Chondrosarcoma in Dogs

Chondrosarcoma is a malignant neoplasm. This type of bone cancer arises from the cartilage of the body, the connective tissue that is found between the bones and joints, often metastasizing to other parts of the body, including the ribs.

This type of bone cancer is the second most common primary bone tumor in the dog, accounting for 5-10% of primary bone tumors in dogs. The most commonly affected site is the nasal cavity, although the ribs, pelvis, long bones of the limbs, and non-skeletal sites have also been reported to be involved.

Chondrosarcomas may be primary, arising within a bone (central) or from the periosteum (peripheral), or secondary, arising by malignant change in osteochondromas

This condition is more common in German shepherds and boxers than in other breeds; the average age of dogs with chondrosarcoma ranges from five years to 8.2 years.

Causes of Chondrosarcoma in Dogs

There is no one true cause for chondrosarcomas. Researchers feel that a combination of environmental and genetic factors can cause chondrosarcomas or at least increase the likelihood that chondrosarcoma or other bony tumors will develop.

Signs of Chondrosarcoma in Dogs

Signs of cancer in dogs often mimic other conditions. It’s important to consider a set of symptoms rather than any one abnormality.

This cancer affects flat bones in the body. This means the tumors can be found in the ribs, nasal cavity, pelvis, and the ribs.

Signs could include:

• Localized swelling (could be painful)
• Decreased appetite
• General Pain
• Dehydration
• Bulging eyes (chondrosarcoma of the skull)
• Sneezing and nasal discharge (tumors in the nasal cavity)
• Rear leg weakness (chondrosarcoma of the pelvis)

Diagnosis

The examinations employed for detecting chondrosarcoma include thorough physical and orthopedic examination, complete blood count, serum biochemistry, radiographs of the affected bone, chest radiographs or computed tomography (CT) scans, bone scan and fine needle aspiration biopsies.

Treatment of Chondrosarcoma in Dogs

Chondrosarcoma is a highly aggressive and life-threatening tumor, which requires prompt treatment. Amputation or limb salvage is usually recommended in cases where there is no metastasis (spreading) of the tumor in the affected limb. For nasal tumors, radiation therapy is normally the treatment of choice. Radiotherapy may also help in prolonging the lifespans in those dogs in which tumors are inoperable.

If the tumor involves the ribs, your veterinarian may decide to remove the affected ribs and nearby lung tissues through a wide excision in order to prevent metastasis. Chemotherapy may also be recommended, but the effectiveness of this therapy has not yet been fully evaluated for CSA. Currently, surgery is the only treatment given for this disease.