Bone cancer refers to a tumor found on or near a bone in the dog’s body. Bone cancer is most commonly located in the arms and legs, but it has been known to occur in the shoulders, spine, ribs, face and skull. This type of cancer strikes mostly larger dogs, with size being the main factor; therefore, there are no types of prevention available for bone cancer.
The most common symptoms are pain and limping. Swelling may also be seen in the joints. You may be able to locate the tumor while petting your dog. Some dogs may suffer from depression. They may become inactive and eat less. When the bone cancer is in the facial region, the dog may have symptoms such as discharge from the nose, swelling or trouble chewing.
Types of bone cancer
There are four primary types of bone cancer. Osteosarcoma (OSA) is the most common, accounting for 85% of bone cancer cases in dogs. It affects 10,000 dogs every year in the United States alone. It has no known cause, although it is believed that bone injuries, fractures, genetics and exposure to radiation may be potential causes. Size and height are the biggest factors, as it primarily strikes large and giant dogs. Young (1-2 years of age) and older (7-9 years of age) dogs are more prone to OSA.
- Chondrosarcoma (CSA) is the second most-common type of bone cancer. It occurs in up to 10% of cases. The tumor forms in the cartilage, so it is not usually as malignant as OSA. CSA occurs in flat bones such as the skull and ribs. CSA is easier to manage than OSA.
- Fibrosarcoma (FSA) is rare, occurring in less than 5% of bone cancer cases in dogs. There are two main types: central and parosteal. FSA is most commonly found in the facial bones, jaw bones, ribs and vertebrae.
- Hemangiosarcoma (HSA) is found in less than 5% of bone cancer cases. It occurs more often in younger dogs and affects the limbs, jaw bones, facial bones and ribs. This type of cancer has a high likelihood of spreading to other parts of the body.
When symptoms are caught early on, anti-inflammatory medication can be given to help your dog manage the pain and reduce swelling. X-rays will be performed to determine the location of the tumor. Even the early stages of cancer can be easily seen through an X-ray. Additional tests are usually not necessary, but in some circumstances, a bone scan or CT scan can provide additional information. If a diagnosis cannot be confirmed, blood work is also useful to determine the cause of lameness. A bone biopsy is another test that may be performed.
In some cases, the tumor can be removed surgically. In more extreme cases, amputation or surgical resection may be required. Chemotherapy is not particularly effective for CSA, but it works quite well for cases of HSA.
After treatment, your dog’s health will need to be managed for the rest of his or her life. Activity will need to be restricted. A pain management program will need to be created to reduce pain and inflammation. The dog will also need regular X-rays and blood work to confirm that the cancer has not returned.