Osteosarcoma is the most frequently diagnosed tumor of bones in dogs. Studies suggest 8-10,000 dogs a year are diagnosed with this condition. It is often the larger breeds who are affected and the long bones of the legs. Often the patient is older in age but younger patients are also affected. The average age is 7 years old. Males do seem to have a predisposition. Post fracture metal implants seem to have a higher rate of this tumor also.


Unfortunately it is a very aggressive type of tumor and has a tendency to spread to other parts of the body. This is called metastasis. The first symptom often noticed is lameness of the leg, with no history of any trauma or accident. Sometimes the affected area swells and the owner notices a change in shape of the leg. The tumor eats away at the bone tissue and causes the bone to be very weak, subsequently small exertion can actually fracture the bone.

The common bones affected are the tibia, femur, humerus and radius.

Breeds Affected

Giant breed are the most commonly affected. Although any breed can be affected there are some that have a higher representation:

  • Rotweilers
  • Labradors
  • Golden Retrievers
  • German Shepherds
  • Dobermans
  • Weimeraners
  • Boxers
  • Great Pyrenees
  • Newfoundlands
  • Bernese Mountain Dogs

How to Find Out If Your Dog Has Osteosarcoma

X Rays are the best way to start to assess the lame leg and the bone integrity. In an affected bone the smooth delineated edges called the cortex of the bone appear moth eaten and no longer smooth. This is called osteolysis of the bone. The way to fully diagnose the tumor is to obtain a sample or biposy with a needle. There is a risk for fracturing an already fragile bone.

90 % of osteosarcomas metastasise to other areas of the body so a thorough work up including bloodwork, chest X Rays and and abdominal ultrasound is advised to assess the patient.


Unfortunately the treatment is very aggressive for osteosarcoma. Limb amputaion and chemotherapy/radiation are the gold standard. With these the quality of life and survival time may be extended depending on the patients stage and the oncologists evaluation.

Pain Control

Pain management is the mainstay of at home treatment for this condition. Quality of life is greatly reduced with the sever pain from this aggressive tumor. Be vigilant to watch for any changes of behaviour and mobility and consult with your vet if your have any concerns regarding pain control. A combination is almost always required.

Please don’t hesitate to call us if you have any questions or want to talk about quality of life regarding your pet. We are here to help and support you.