How does this cancer typically progress?
Osteosarcoma in dogs is extremely aggressive. At the time of diagnosis, about 90-95% of dogs will have micrometastasis, meaning the cancer cells have already spread elsewhere even though they are not detectable. Therefore, staging (searching for potential spread to other locations in the body) is always recommended in dogs with osteosarcoma. This may include bloodwork, urinalysis, X-rays of the lungs, and possibly an abdominal ultrasound, CT or MRI. If any lymph nodes are enlarged or feel abnormal, further sampling may be pursued to determine if spread is present.
When should I take my dog to see a vet?
Bone cancer is an aggressive disease that has a tendency 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 parents should always take symptoms of bone cancer in their dogs very seriously! Osteosarcoma can quickly become fatal if not detected early enough to treat.
What are the signs of osteosarcoma?
Osteosarcoma is very painful. If your dog has an osteosarcoma of the limb (appendicular osteosarcoma), lameness or a distinct swelling may be noted. Your dog may be more lethargic, have loss of appetite, and be reluctant to walk or play due to pain caused by the tumor on the bone.
The most common areas for osteosarcomas in dogs are the radius/ulna above the carpus (front knee/wrist) and the tibia/fibula below the stifle/knee), but osteosarcoma of the digits (toes), femur (above the stifle), and hip occur as well.
Most dogs with osteosarcoma will limp on the affected limb. Swelling is usually noted where the tumor has grown, and the area will be warm to the touch due to of the extreme inflammation. Your veterinarian will take X-rays of the region. Osteosarcomas appear lytic (meaning pieces of bone are missing) or ‘moth-eaten’ due to the loss of normal bone tissue. Fractures can be present if the bone has weakened enough.
Once a lesion is suspected, a more definitive diagnosis may be obtained by a fine needle aspiration. This involves taking a small needle with a syringe and suctioning a sample of cells directly from the lesion and placing them on a microscope slide. A veterinary pathologist then examines the slide under a microscope. This is performed under sedation. If this procedure is not diagnostic, a bone biopsy may be warranted. In most cases, lytic bone lesions found on X-rays are indicative of either an infectious or malignant process and further diagnostics are always recommended.
Bone Cancer in Dogs: Causes, Symptoms and And Answers to Frequently Asked Questions
Bone cancer is one of the most common types of cancer in dogs. Bone cancer must be detected and treated in its very earliest stages in order to achieve the best possible treatment outcomes. Here is more from our Memphis vets on the symptoms and treatments for bone cancer in dogs.
At Memphis Veterinary Specialists & Emergency in Cordova, osteosarcoma is the most common form of primary bone cancer our vets sees in dogs. Osteosarcoma accounts for approximately 95% of all bone tumors diagnosed in dogs. This aggressive condition leads to the malignant, abnormal growth of immature bone cells.
Left untreated osteosarcoma will spread rapidly throughout the body causing other health issues, and can quickly become fatal for dogs. However, if osteosarcoma is diagnosed early, life-saving surgery to remove the cancerous limb may be possible. Swift removal of the limb can help to prevent the disease from spreading.