When it comes to hearing about osteosarcoma, no pet parent ever wants to hear that it’s what’s affecting their fur baby. The signs can be easy to miss, which is why dog owners need to know what to look out for and get treatment as soon as possible. The frustrating part of the whole thing, is that while the prognosis can seem pretty bleak, there are options that might lengthen your pet’s life.

Table of Contents:

• What is osteosarcoma in dogs?
• How common is osteosarcoma?
• Is osteosarcoma hereditary in dogs?
• What dog breeds are prone to cancer?
• What causes osteosarcoma in dogs?
• What are the symptoms of osteosarcoma?
• How to tell if a dog has cancer
• How to treat cancer in dogs
• How much does canine chemotherapy cost?
• Key Takeaways

Pro Tip: There will be cases where pet parents cannot afford the costs associated with chemotherapy and surgery. This nightmare can be avoided with a pet insurance policy. Now you can compare pet insurance plans to find out which plan best suits your pup.

What is osteosarcoma?

Osteosarcoma (OS or OSA) is a type of cancerous tumor in the bone,article focusing on a rare animal tumor composed of cancer that are found in natural habitats and may have the potential for rapid and extensive spread. The most common form of the cancer, known as canine osteosarcoma, takes the form of a big, hard lumped on the dogs’ forelegs in most instances. But the dog’s hind legs, facial bones, jaw, spine, ribs, and pelvis can also be involved.

The tumor, or sarcoma, can be excruciatingly painful, and frequently leads dogs to walk with one leg lifted off the ground in an attempt to avoid putting pressure on the affected limb. Cancer: If the disease metastasizes (moves to other parts of the body), it can result in a number of secondary problems like difficulty breathing when the lungs are damaged.

How common is osteosarcoma?

The OSA is the most prevalent form of primary bone tumor in both the dog and humans, accounting for more than 95% of cases of canine bone cancer. Fibrosarcoma, chondrosarcoma, and hemangiosarcoma are other bone cancers. (Note that “primary” is where the disease started, not metastatic cancer in the legs, ribs or hips seeping into the bone from elsewhere.)

Bone cancer is a rare form of disease in humans, but dogs have been found to develop the disease at rates 27 times greater than humans.

Is osteosarcoma hereditary in dogs?

A number of genetic risk factors predispose a dog to osteosarcoma. Male dogs are also affected with bone cancer more than females and dogs who are castrated or neutered before they reach the age of one. The disease seems commonest in young dogs at 18-24 months, and in seniors 7-9 years of age.

Which breeds of dogs are most susceptible to cancer?

There also seems to be a genetic predisposition in large and giant breed dogs, with bone cancer being more prevalent in breeds such as:

Bernese Mountain Dogs

Doberman Pinschers

Golden Retrievers

Great Danes

Great Pyrenees

Irish Wolfhounds

Irish Setters

Newfoundlands

Rottweilers

Saint Bernards

Weimaraners

Note that there are different types of canine cancers and a breed that is pre-disposed to bone cancer is not necessarily a breed that is genetically pre-disposed to lymphoma, for example.

What causes osteosarcoma in dogs?

The etiology of osteosarcoma in the dog is unknown. A few theories indicate that the etiology of the disease may be associated with old fractures, bone pathology and repetitive bone injuries.

As is the case with cancer in people, in most cases, there are various factors that contribute to cancer in dogs, some genetic and some environmental. Osteosarcoma is a disease that can strike all dogs, so it’s up to you to watch for specific signs that may indicate the presence of bone cancer.

What are the signs of osteosarcoma?

Symptoms of a bone tumor in dogs can be subtle, which makes detecting early-stage osteosarcoma so difficult. Cancer begins in the deepest part of the bone, so your pup may have no symptoms of pain at first. When cancer advances and the tumor grows, you might see them exhibiting signs of osteosarcoma in dogs, such as:

Persistent or intermittent inability to put weight on one or more limbs (lameness)

Lethargy

Loss of appetite

Joint pain

Swelling or a lump, especially if the tumor is in the ribs, jaw, or skull

Neurologic signs, such as a wobbly gait or seizures, if the bone cancer is located in the spine or skull

Problems opening your mouth, chewing, or swallowing if the tumor is in your jaw

Rib tumors cause breathing issues

As it becomes larger, the cancer will weaken the bone, leading to a break or fracture

Start by taking your dog to the vet as soon as you see symptoms of a dog’s bone cancer. Osteosarcoma in dogs is very aggressive, and an early diagnosis can prolong your pet’s life.

How do you know if a dog has cancer?

Your vet will conduct a routine physical exam, also employing an orthopedic exam to eliminate alternative causes of lameness.

The vet will also perform X-rays, especially if there’s a lump on a dog’s leg. If they see anything suspicious, a bone biopsy may be needed to reach an accurate diagnosis.

They may also request chest X-rays, a CT scan and a blood test to check the pet’s general health and verify whether the cancer has metastasized. Sadly, >90% of dogs have spread of the tumor at the time of diagnosis, with the most common site of spread being the lung.

If you have reason to believe your dog has a bone tumor, make sure to consult your vet. They can properly diagnose you and talk to you about treatment options.

How to treat cancer in dogs

How osteosarcoma is treated in dogs will be based on a number of factors, such as where the tumour is, and whether or not the cancer has spread.

If the tumor is in the limb, amputation will almost certainly be recommended by a vet**, the cancer is aggressive. Even though I know it may seem like such a radical measure, dogs do just fine on three legs. The next step is generally chemotherapy to help prolong the animal’s life.

(1) Stereotactic irradiation may be useful when surgery is not feasible because of the location of the tumor. This could be a possibility before amputation for early-stage osteosarcoma if the cancer hasn’t invaded most of the bone.

Palliative care, when done right, can make a dog’s last days or weeks significantly better with the right pain management drugs, dietary strategies and human engagement. It may also involve nonsurgical pain-relief radiating therapy.

What does chemotherapy for dogs cost?

Osteosarcoma treatment costs can be exceptionally expensive and well into the $10,000 range. It is difficult to calculate the average cost of dog cancer treatment as there are several variables (like the dog’s size, which can affect how much chemo is needed) involved with the cost of chemotherapy, for instance. This is what you’ll be looking at in terms of costs for bone cancer treatment in dogs:

Cost for diagnostic testing with oncologist in your room – $800 – $1,000

Price to have the dog’s tumor surgically removed, Varies by location and degree of expertise of surgeon: $1,000 to $3,000

The price of dog chemotherapy – $2,000 to $4,000

Extra cost of palliative radiation Another to $5K $2 – $5K

Pro Tip: If your dog is predisposed to cancer, consider getting a pet insurance policy while he’s still healthy. Your pup is not, one hopes, wrestling with osteosarcoma, but there are more-common cancers that pet insurance can cover — and also common illnesses like kennel cough.

Outlook, recovery and survival in dogs with cancer

The outlook for osteosarcoma in dogs will vary depending on multiple factors, such as the extent of the disease, treatment chosen, etc. In early-stage osteosarcoma, when cancer is discovered before it has spread, the prognosis is better. **If osteosarcoma metastasizes and spreads to the lymph nodes, lungs or other parts of the body, the dog’s prognosis will be very poor.

Dogs with bone cancer, provided they are treated with chemotherapy and stereotactic radiation, enjoy a median life expectancy of about a year. Osteosarcoma survival time is comparable to dogs treated with amputation and chemotherapy. In comparison, with amputation alone, the dogs can live with cancer for about three months. Approximately 15% to 30% of dogs receive a survival time of 2 years.

Osteosarcoma is frequently fatal, even with treatment and surgery. Because of this, some pet owners elect to not treat, instead opting for the most humane choice of euthanasia.

If your dog has been diagnosed with osteosarcoma, speak with your vet to find out what the best plan of action is for you and your family.

Key Takeaways

Osteosarcoma is an aggressive tumor that originates in the bone and frequently appears in the limbs of dogs, although it can develop in any part of the body.

Large breeds are most likely to develop canine osteosarcoma, but veterinarians are not sure exactly what causes bone cancer in dogs.

This type of bone cancer is extremely aggressive in dogs, and can rapidly spread throughout the body, typically to the lungs, when it involves limbs.

Call your vet as soon as you notice a lump on a dog’s leg. If you know how to identify symptoms of canine osteosarcoma, you can reduce the spread of cancerous cells, thus ensuring your canine friend enjoys a quality life.