Osteosarcoma (OSA) is the most common type of bone cancer in dogs. It is an aggressive and painful disease that typically affects large and giant breed dogs, though any breed can develop it. This cancer most commonly arises in the limbs, but it can also occur in the skull, ribs, spine, and other bones. Understanding osteosarcoma, its clinical signs, diagnostic testing, and treatment options can help dog owners make informed decisions about their pet’s care.
Recognizing the Signs of Osteosarcoma
The first sign of osteosarcoma is often lameness. Because the tumor weakens the bone, some dogs experience sudden fractures with minimal trauma, called pathological fractures. Other symptoms may include:
- Swelling at the site of the tumor
- Pain, which may worsen with activity
- Reluctance to bear weight on a limb
- Decreased activity or reluctance to play
- Loss of appetite or weight loss
Since these signs can be mistaken for arthritis or minor injuries, early veterinary evaluation is crucial.
How is Osteosarcoma Diagnosed?
Veterinarians begin with a thorough physical exam and imaging. X-rays of the affected limb often reveal a characteristic bone pattern that suggests osteosarcoma. However, a definitive diagnosis requires additional testing.
- Fine Needle Aspiration (FNA) or Biopsy: A sample of the tumor cells is collected and examined under a microscope to confirm the presence of cancer.
- Histopathology & Advanced Genetic Testing: Histopathology, the microscopic examination of tumor tissue, remains the gold standard for diagnosis. Recent advancements in genetic testing allow for molecular analysis of the tumor, helping veterinarians predict how aggressive the cancer may be and tailor chemotherapy protocols to improve treatment outcomes.
- Staging Tests: Because osteosarcoma tends to spread (metastasize) quickly, additional tests such as chest X-rays and abdominal ultrasound help determine whether the cancer has spread to the lungs or other organs.
Treatment Options for Osteosarcoma
Osteosarcoma is a highly aggressive cancer, but treatment can improve both longevity and quality of life. The primary treatment options include:
- Amputation: The standard treatment for appendicular osteosarcoma is limb amputation, which removes the painful tumor and improves quality of life. Many dogs adjust well to three legs and remain active.
- Limb-Sparing Surgery: In some cases, especially if amputation is not an option due to concurrent orthopedic or neurological disease, specialized surgical techniques may preserve the limb.
- Chemotherapy: Since osteosarcoma frequently spreads, chemotherapy is recommended to slow metastasis. Advances in genetic testing allow veterinarians to choose the most effective chemotherapy drugs based on the tumor’s unique genetic profile.
- Radiation Therapy: For dogs that cannot undergo surgery, palliative radiation helps control pain and improve comfort.
- Pain Management & Supportive Care: Nonsteroidal anti-inflammatory drugs (NSAIDs), opioids, and adjunctive therapies such as acupuncture can help manage discomfort.
Prognosis: What to Expect
Without treatment, osteosarcoma is a rapidly progressing disease, with survival times typically ranging from weeks to a few months. Dogs that undergo amputation alone live an average of four to six months. However, with the addition of chemotherapy, survival times often extend to one year or longer, with some dogs living two years or more. Advances in precision medicine and genetic testing are continually improving these outcomes.
The Role of a Veterinary Oncologist
When facing a cancer diagnosis, a veterinary oncologist plays a vital role in a dog’s care. These specialists have advanced training in diagnosing and treating cancer, ensuring that each patient receives the most effective and up-to-date treatments available. They can guide pet owners through treatment decisions, discuss emerging therapies, and create a tailored plan to maximize quality of life. Consulting a veterinary oncologist early in the process can make a significant difference in the outcome and comfort of a dog with osteosarcoma.
Osteosarcoma is a challenging disease, but early recognition and intervention can improve a dog’s prognosis and quality of life. Advances in genetic testing and oncology are opening new doors for more personalized and effective treatment strategies. If you suspect your dog may have osteosarcoma, seek veterinary care as soon as possible. With the right support and a dedicated veterinary team, dogs with osteosarcoma can continue to live happy, comfortable lives for as long as possible.
Barks & Recreation is proud to feature Dr. Eileen Savier CVA, CVCH as our Veterinary Blogger in our “From the Vet” Series — offering information related to the health and welfare of your furry family members! Currently part of the team of doctors at Keystone Veterinary Clinic, Dr. Savier is a 2012 Graduate of the Ross University School of Veterinary Medicine, She completed her clinical experience at The Ohio State University and after veterinary school she pursued further education and certification in Veterinary Acupuncture, Chinese Herbal Medicine, and Fear Free veterinary visits. Dr. Savier has a special interest in integrative medicine, animal behavior, and internal medicine and is committed to improving animal health care by integrating Eastern and Western philosophies. She enjoys working with fearful & aggressive dogs and cats and she has had additional training in low stress handling techniques and encourages positive reinforcement during exams and procedures. Her clinical interests include pain management, animal behavior, geriatric patient care, and internal medicine.
Dr. Savier shares her home with two (soon to be three) dogs, two cats, and a toddler. She lovingly refers to her two dogs as Coconut Retrievers as they were rescue dogs she brought home from the island of St. Kitts. In her free time she enjoys spending time with her family, going to the beach, and planning her next Disney vacation.
