Bone cancer in dogs
Osteosarcoma in dogs, also known as bone cancer, is the most common tumour of the bone in dogs. It most often occurs in the long bones of the front limbs (humerus, radius) or hind limbs (femur) and is frequently seen in middle-aged, large, and giant breed dogs - Boxer Dogs, Doberman Pinschers, Golden Retrievers, German Shepherd Dogs, Great Danes, Greyhounds, Irish Setters, Irish Wolfhounds, and Rottweilers.
The reason why a particular pet may develop this, or any tumour, is not straightforward. Most seem to be caused by a complex mix of risk factors, some environmental and some genetic or hereditary.
Unfortunately, this is a very aggressive tumour and often metastasises (spreads to the lungs) early in the disease. While there is no cure for Osteosarcoma, there are treatment options to help delay the progression of the disease and alleviate pain.
Written by Dr. Mariella Roberts, Veterinary Surgeon, Animal Trust Vets CIC | Published March 2025 | Review date March 2027 | This advice is for UK pets only and is not a replacement for seeing a vet
Osteosarcoma symptoms in dogs
Osteosarcoma is often very painful. The most common signs of Osteosarcoma may depend on the tumour location, often include:
Lameness, or reluctance to walk
Firm, localised swelling, most commonly on the limbs
Loss of muscle mass to the affected limb
There may be less common or nonspecific signs secondary to pain such as no eating or behaviour changes.
When to contact your vet
Bone cancer is an aggressive disease that tends to spread extremely quickly, so urgent treatment is required. If your pet is displaying any of the symptoms listed above call your vet immediately to book an emergency appointment. Pet owners should always take symptoms of bone cancer in their dogs very seriously. Osteosarcoma can quickly become fatal if not detected early enough to treat.
Diagnosis
To properly diagnose osteosarcoma:
X-Ray and a physical and orthopaedic examination to rule out other causes of lameness.
Biopsy, to obtain a definitive diagnosis and determine the best treatment plan for your dog.
Other diagnostics – chest X-rays or a computed tomography (CT) scan (usually done at referral hospitals), blood tests, and a urine test will usually be done to assess your dog’s overall health and determine if cancer has spread. In over 90% of dogs, the tumour will have already metastasised (spread) at the time of diagnosis.
Osteosarcoma treatment for dogs
Because of the aggressive nature of osteosarcoma, the best treatment is often to amputate the limb and then begin chemotherapy. Although amputation may seem extreme, it can help to prevent the cancer from spreading and most dogs have little trouble adjusting to life with three legs. If surgery isn't an option for your dog, a combination of radiation and chemotherapy may be beneficial.
Prevention of bone cancer in dogs
There is no sure way to prevent this type of cancer from occurring in dogs. Regular checks up with your vet are highly recommended to catch any potential signs or symptoms early on.
Outlook
Factors like your dog's age, weight, and the tumour's location will all influence the outlook.
Dogs diagnosed and treated for bone cancer can usually live for another 1-6 years. Unfortunately, bone cancer is extremely aggressive and often proves fatal even when treated with surgery and other therapies, but your vet will collaborate to ensure your dog's comfort and quality of life for as long as possible.