Osteosarcoma

I just learned that a friend's dog has osteosarcoma. This is a type of bone cancer that is generally found in the leg bones of large breed dogs. Many years ago I had a Rottweiler that developed osteosarcoma. The cancer generally occurs in middle aged or older dogs. It is an aggressive cancer and can become more painful as it grows outward and destroys the bone from the inside out.

In my Rottweiler, I first noticed that she was limping. The limping became worse and a large lump appeared on the leg. This large lump was the tumor that was growing inside the leg bone. I had to stop all obedience work with her because tumorous bone is not as strong as normal bone and can break easily. Such a fracture won't heal readily.

I took Zoe in to the vet and a radiograph revealed the presence of osteosarcoma. There are several characteristics that can be observed on the radiograph:

• The “lytic lesion” – looks like an area of bone has been eaten away.

• The “sunburst” pattern – shows as a corona effect as the tumor grows outward and pushes the more normal outer bone up and away.

• A pathologic fracture may be seen through the abnormal bone.

Osteosarcoma does not cross the joint space to affect other bones comprising the joint.There are few options with osteosarcoma. Some vets indicate that amputation of the leg may buy some time. Others suggest amputation and chemotherapy. The problem is that the dog is then very uncomfortable and by the time the disease is diagnosed in the leg, it has likely spread to the organs of the chest such as the lungs.

I hope that Cayenne will continue to enjoy life as much as possible. She has been given around 4 months. She doesn't go to the beach anymore but seems happy enough limping around the house. It's sad to see such a once active dog no longer able to do the things that she so enjoyed. Osteosarcoma is a bad disease and one that I had hoped to not see among my doggy friends again.