The Five Types of Bone Cancer in Dogs

Bone cancer in dogs is quite common. Each year, 10,000 new cases are reported. Success rate of treatment depends on the type of cancer, ranging from very little chance of success to easily treated.

1. Metastatic Bone Cancer

There are two basic groups of bone cancer: primary and metastatic. Metastatic bone cancer originates in another part of the body and migrates to the bone. Since this means the cancer is already spreading aggressively, metastatic bone cancer can't be treated if there is a larger tumor elsewhere in the body. The original cancer must be treated first or the bone cancer will just reappear later.

2. Osteosarcoma

The second group of bone cancer, primary, originates from the bone. The most aggressive type of primary bone cancer is osteosarcoma, which originates from cells that deposit bony minerals. Osteosarcoma is highly malignant, and 95 percent of tumors metastisize by the time of diagnosis. Most dogs will die when the tumor moves to the lungs or another vital organ.

Your dogs will often show lameness in the affected limb and may even have swelling, but at this point, the cancer has often metastisized so aggressive treatment is important.

Treatment often involves removal of infected limb as well as chemotherapy to treat other affected areas. With amputation only, dogs have a survival time of 3 to 5 months, but with chemotherapy, dogs have been known to live up to several years after diagnosis.

3. Chondrosarcoma

Chondrosarcomas are generally less aggressive and, thus, less likely to spread. They arise from cartilage joint surfaces at the end of bones and tend to stay there. Chondrosarcomas are usually diagnosed when the dog begins to show lameness in the affected limb. There may be some swelling of affected area. Treatment can usually be solved with amputation of the affected limb.

4. Fibrosarcoma

Fibrosarcomas are locally invasive and unlikely to spread unless tumor is very high grade. They originate in the fibrous connective tissue adjacent to the bone. They are detected and treated same as chondrosarcoma.

5. Synovial Cell Carcinoma

Though not true bone cancer, this type of cancer also causes bone destruction. They originate in the joint tissues and then invade the surrounding bone. Grade 1 and 2 synovial cell carcinomas are generally easily treated and cured with amputation. However, regardless of treatment, dogs affected with a Grade 3 carcinoma usually die within a few months.

There is no prevention for bone cancer, and there may even be a genetic component. Larger breeds are more often infected because they have more bone area. Currently, amputation is the most common treatment, but dogs can live long and happy lives minus one limb. Regularly inspect your dog for lumps since early detection leads to a higher success rate.