The best bone cancer treatment options depends on whether the bone cancer is primary or secondary. The latter starts in other organs and, at some point, it extends to the bones through metastasis. In order to treat bone cancer in this situation it is necessary to treat the tumor that metastasized. Primary bone cancer in dogs, which is also known as canine osteosarcoma, starts in the bones.
Characteristics of Bone Cancer
Every bone of the dog can be affected by osteosarcoma, but the limbs are affected more frequently. In fact, in between 75 and 85 percent of the cases the tumor starts in the limbs. In this particular situation, canine bone cancer is called appendicular osteosarcoma. The tumor starts deep inside the bone and it grows progressively. At some point, the bone is cracked from the inside out. As the tumor gets bigger, the sensation of pain felt by the dog becomes more intense. In time, the tumor replaces the normal bone. Since the tumorous bone does not have the same strength as the normal one, it breaks easily. The result, which is called a pathologic fracture, helps veterinarians to confirm the osteosarcoma diagnosis.
Canine Osteosarcoma Diagnosis
X-rays represent one of the best ways of confirming the diagnosis. The limb affected by osteosarcoma is radiographed and the result is analyzed by the veterinarian. In the majority of the cases radiography is conclusive, but if there are any doubts an additional diagnostic test may be needed. Biopsy, the second test, provides absolute proof of diagnosis as it involves the analysis of a small portion of bone under the microscope. After evaluating the bone sample oncologists are able to tell whether the dog suffers from osteosarcoma or from some other health condition.
Pain Relieving Treatment Options
The treatment of bone cancer in dogs focuses on two different goals: relieving the pain and treating the bone tumor. As the latter may take some time, it is highly recommended to deal with the sensation of pain first. This can be achieved through one of the following methods:
- Amputation of the limb
- Drugs
- Limb sparing surgical procedure
- Radiotherapy for pain management
Amputation may seem a very drastic solution, but it is really necessary when the tumor destroyed a great part of the bone and the pain is very strong. Fortunately for dogs, their activity level is not restricted when a limb out of four is amputated. Unless the dog received radiotherapy, it will survive for 4 to 5 months after being diagnosed. Amputation may increase the comfort of the dog in this period.
Drugs are also a reliable treatment option for relieving the pain. Some of the medicine recommended for osteosarcoma includes:
- Adjunct pain relievers such as Gabapentin and Amantadine
- Bisphosphonates
- Narcotic pain relievers
- NSAIDs (non-steroidal anti-inflammatory drugs)
Limb sparing surgical operations involves the removal of the tumorous bone and the replacement by a bone graft. As an alternative, the remaining bone can grow again, due to an innovative procedure called bone transport osteogenesis.
The radiotherapy implies three sessions, the first two 7 days apart and the latter after a fortnight. This particular treatment option does not only relieve the pain, but it also extends the life of the dog. Depending on the stage of osteosarcoma and on the intensity of pain, additional radiotherapy may be required.
Treatment Options for the Bone Tumor
As in the case of many other types of cancer, chemotherapy represents one of the best ways of managing the dimensions of the tumor. The drugs used for chemotherapy include:
- Carboplatin
- Cisplatin
- Doxorubicin
As an alternative, the last two can be used together. Each of these drugs is characterized by different survival rates, but it is the duty of the veterinarian to decide which is more appropriate for your dog.