Canine Bone Cancer

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The Big Story on Osteosarcoma

Osteosarcoma is an aggressive cancerous tumor that develops in the bone cells of a dog and rapidly spreads throughout the body resulting in death. There is currently no cure.

By the Numbers

  • 10,000 dogs diagnosed with osteosarcoma each year.
  • Osteosarcoma occurs 10x more frequently in dogs than humans.
  • 20% to 50% greater risk for male dogs.
  • Accounts for roughly 5% of all canine tumors and 85% of all canine bone tumors.
  • 80% of dogs die within two years of diagnosis and in 90% of cases, the cancer has already spread upon diagnosis.
  • 4,000 - 8,000 dogs die annually from metastatic disease.

Osteosarcoma is linked to rapid growth and it is more common in large and giant breed dogs.

To counteract this trend, large and giant breed puppy food has reduced levels of available energy, designed to slow the time needed for large breed puppies to reach their maximum size.

Believed to be fundamentally a genetic disease, there is currently no definitive connection between family members, yet osteosarcoma is certainly more prevalent in some breeds.

  • 75% - 85% of osteosarcoma cases occur in the limbs.
  • 15% of all Scottish Deerhounds die from osteosarcoma.
  • Dogs over 80 lbs. are 60 times more likely to develop osteosarcoma than dogs weighing less than 75 lbs.
  • Two of the most common causes that can be linked to osteosarcoma in dogs are rapid growth and blunt bone injury.


The most common symptoms of osteosarcoma include swelling, visible lameness, joint and bone pain, and even bone fractures caused by the weakening of bones due to the osteosarcoma growth. If you notice your dog limping or in pain, you should immediately contact your vet.

Using an X-Ray, MRI, or CT scan to identify the location of a tumor, a surgeon will then perform a biopsy on the tumor to collect cells to determine if it is indeed osteosarcoma.

Treatment and Prognosis

"Leg of Life"

Currently, the most effective standard of care, if the tumor occurs in a limb, is to amputate to prevent the spread of the cancerous cells. When combined with adjuvant chemotherapy survival rates can be improved.

Chemotherapy is Only Effective When the Primary Tumor is Removed

  • 1 Year: 50% of dogs treated with the current standard of care survive at least 1 year (or 10% of a lifetime).
  • 2 Years: 20% of dogs with appendicular osteosarcoma who have the limb removed and undergo chemotherapy treatment, survive more than two years.
  • 5-6 years: Some dogs can live 5 or more years after the standard treatment.

The Future of Treatment

$5 Million for 5 Years of Research

Morris Animal Foundation has committed $5 million to new research, funding the next five years in the battle against osteosarcoma in dogs.


A bacterium-derived drug that has traditionally been used to prevent rejection in organ transplants. It works by preventing the activation of T cells and B Cells. A previous study found that Rapamycin showed promise in the treatment of osteosarcoma in dogs. Two offshoot clinical trials are currently underway to study the effectiveness of rapamycin in the post-surgery treatment of metastatic disease.

Human Clues

Recent studies have shown that the fibroblast growth factor signaling pathway is abnormally activated in a variety of human tumors. Morris Animal Foundation researchers are investigating the role of this pathway in bone cancer spread and its potential as a new therapeutic target.

Tailoring Treatment to Individuals

Cancer gene signatures have been shown to be good predictors of how a tumor will respond to a specific chemotherapy drug.

How You Can Help

With the continued support of Morris Animal Foundation by Orvis and people like you, answers to treatment and survival of osteosarcoma in dogs are within reach.

Visit for more information about the fight against osteosarcoma and Morris Foundation’s many other projects.

You can help in the fight against canine cancer through the Orvis Cover Dog Contest. Visit to get started.


All information sourced from the Morris Animal Foundation.

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Orvis Canine Cancer Campaign

Canine cancer affects 1 in 4 dogs, and half of all dogs over ten years old. Fortunately, in recent years, veterinary scientists have made tremendous research strides—recent studies have led to new research tools, better diagnostics, and improved chemotherapy treatments. But there is more work to be done. That's why The Orvis Company partners with Morris Animal Foundation, a nonprofit organization that invests in animal health science, to support canine cancer research, and improve the health of all dogs.

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Is Your Dog the Next Cover Dog?

Partnering with Morris Animal Foundation, a global leader in advancing veterinary medicine, we’ve raised more than $1 million through our Cover Dog contest to support canine cancer research. Enter your dog, vote for your favorite, and help us raise $1 million more in the fight against canine cancer.

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