If your dog receives an osteosarcoma diagnosis, it can leave you feeling devastated. However, there are treatment options available for this aggressive bone cancer which can allow you to enjoy more pain-free time with your pet.
Learn more about osteosarcoma in dogs, how to recognize the signs of the disease, and what to speak with your veterinarian about to help you navigate your pet’s diagnosis.
Osteosarcoma accounts for at least 85% of bone cancers in dogs seen by veterinarians, according to Dr. Cheryl London, DVM, PhD, ACVIM, an associate dean of research and veterinary oncologist at the Cummings School of Veterinary Medicine at Tufts University.
It’s most commonly seen in the appendicular skeleton of dogs (the long limb bones). However, Dr. London explains it can also occur in the axial skeleton (consisting of the skull, vertebrae, ribs and sternum). “These are the flatter bones, like the scapula in the shoulder and the jaw,” she says. Very rarely, osteosarcoma occurs outside of the skeleton. “We call that extraskeletal osteosarcoma,” Dr. London says. “We’ve seen it in the mammary gland and the spleen.”
The growing tumor damages normal bone, making it more susceptible to breaking, and because this type of cancer is aggressive, it can rapidly metastasize, spreading to the lungs.
alexsokolov/Getty Images Plus
Dr. London explains that osteosarcoma occurs primarily in large and giant breed dogs. “There is probably both a genetic and size component, meaning there are some breeds of dogs that seem to be significantly at increased risk for developing this cancer,” she says. These breeds include:
However, it’s important to recognize that osteosarcoma can occur across various sizes and breeds. Though it’s more common in middle-aged and senior pets, this cancer can affect dogs of any age.
Osteosarcoma is an aggressive cancer which can metastasize (spread to the lungs) before owners notice any obvious signs in their dogs. Signs are often nonspecific and vary depending on the location of the cancer and how quickly the bone breaks down. For osteosarcoma affecting the long limb bones, such as the femur, tibia, radius, and humerus, the first signs you might see in your dog are limping or lameness.
Deborah Mandell, VMD, is a Professor and Director of Emergency Services at Matthew J. Ryan Veterinary Hospital of the University of Pennsylvania. She explains that your dog may initially respond to conservative medical therapy with non-steroidal anti-inflammatory drugs (NSAIDs). Unfortunately, it’s likely that the symptoms will typically worsen again. “The area of the tumor is also typically painful on palpation,” she says. You may even be able to see the mass or swelling, depending on which bone is involved.
“Sometimes we only see dogs after they have suffered a pathologic fracture of the area of the cancer in the leg, where they’re acutely extremely painful,” Dr. Mandell says. “If the cancer is on another bone, then pain and swelling will be a common sign, as will systemic signs like lethargy and anorexia secondary to the pain.”
Some subtle signs your dog is in pain include:
Typically, the first thing your veterinarian will do once they establish where they believe the pain is coming from is take an x-ray. “In 99% of dogs, by the time they’re lame and have failed standard treatment for a soft tissue injury, there’s usually something pretty obvious you can see,” Dr. London says. When bone cancer is present, there will typically be signs of bone destruction and sometimes new bone formation on the x-ray.
A fine needle aspiration, which removes some cells from the affected area to examine on a slide, can confirm cancer. “However, that relies upon there being enough bone destruction to get the needle in for a sample,” Dr. London says.
leaf/Getty Images Plus
While a successful fine needle aspiration can give you a diagnosis of sarcoma, most consistent with osteosarcoma, there are other types of bone cancers which vary in their malignancy. These include chondrosarcoma, fibrosarcoma, hemangiosarcoma, and histiocytic sarcoma.
A bone biopsy can provide a more definitive diagnosis, but it’s a much more involved process. “For most of our patients, we don’t end up doing a bone biopsy because they choose to go forward with amputation,” Dr. London explains.
Your veterinarian will likely also perform further testing, such as bloodwork, urinalysis, and chest x-rays, to look for signs of progression of the disease.
There is currently no cure for osteosarcoma in dogs, and it’s a highly metastatic form of cancer. This means it has often spread microscopically to other body parts by the time you receive a diagnosis. “Unfortunately, we don’t have methods to detect osteosarcoma at its earliest point in the way mammograms in humans detect things when they’re just a couple of millimeters in size,” Dr. London says.
However, there are treatment options which can slow the progression of the cancer and help manage a dog’s pain. How you decide to proceed following a diagnosis is highly individualized based on various factors. “Typically, we tell owners that there’s no right or wrong decision,” Dr. London says. “Quality of life plays a really important role in decision-making, as do finances.”
“The first thing we want to do is make sure there’s no obvious evidence that it has spread to the lungs, so we always take chest x-rays,” Dr. London says. “If there’s obvious spread to the lungs, it tends to be very poorly responsive to treatment (less than 10% response rate).” She explains that in these cases, veterinarians will typically recommend palliative care to keep your dog comfortable.
Even if it hasn’t spread to the lungs, you may opt for palliative care, focussing on managing the pain, since bone tumors are very painful, and regularly assessing your dog’s quality of life. This is particularly true if you have financial constraints or your dog is not a good candidate for amputation — maybe they have severe arthritis, obesity, or other illnesses.
“For most patients, the treatment of choice is amputation followed by some form of injectable chemotherapy,” Dr. London says. While this won’t cure your dog of osteosarcoma, removing the primary tumor and administering anti-cancer drugs slows the spread of the disease and offers immediate relief from pain.
While amputation can seem a radical option, Dr. London explains that the overwhelming majority of owners are happy with their dog’s quality of life post-surgery. “Dogs don’t have the psychological challenges that we do with losing a leg, and they go back to ambulating [moving around independently] very quickly,” she says.
Sonja Birkelbach - stock.adobe.com
Chemotherapy treatment administered by an oncology specialist begins soon after surgery. “Typically, we use a chemotherapy drug called carboplatin, which is given by IV injection every three weeks in four to six treatments,” Dr. London explains. “It’s a really well-tolerated drug and doesn’t cause a lot of side effects.”
Dosing differs from human chemotherapy treatment, so your dog won’t typically suffer from nausea or diarrhea. “Some owners say their dogs feel fine with no side effects at all,” Dr. London says. “If anything, owners may say their dog feels a little tired after the treatment and maybe won’t eat for a day.”
If your dog is not a good candidate for amputation, local radiation therapy is another treatment option for osteosarcoma. Palliative radiation can help with pain control, and high-dose stereotactic radiation works to kill off the tumor.
“Whether a dog is a good candidate for radiation and the type given depends on where the tumor is located, how much bone destruction there is, and whether the patient is at risk for fracture because the bone is very weakened from the tumor destroying it,” Dr. London explains.
Treatment for osteosarcoma in dogs is not curative, but it can markedly improve your pet’s quality of life and extend the time you have left to spend with them.
Dr. Mandell explains that with palliative care, the pain typically becomes resistant to medication after weeks to maybe a few months.
“The median survival time with amputation and chemotherapy is around 11 months,” Dr. London says. “About 25% of dogs will make it to two years. Then a much smaller amount, like 5% or less, makes it to three years after amputation.” She explains that this is because the cells that spread before amputation eventually become resistant to treatment and start growing again.
Amputating without following up with chemotherapy reduces median survival times to around three to four months, and radiation therapy offers a median survival time of about six months.
While these figures can be a helpful guide when making treatment decisions, it’s important to remember cancer is unpredictable. The main focus is typically on providing the best quality of life for however long your dog has left.
On a positive note, there’s a lot of promising research being conducted on osteosarcoma in dogs. “We’ve had some marginal successes with immune stimulant therapy, but most of the research is in its early stages right now,” Dr. London explains.
The post Osteosarcoma in Dogs: Signs, Diagnosis, Treatments appeared first on American Kennel Club.
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Learn more about osteosarcoma in dogs, how to recognize the signs of the disease, and what to speak with your veterinarian about to help you navigate your pet’s diagnosis.
What Is Osteosarcoma in Dogs?
Osteosarcoma accounts for at least 85% of bone cancers in dogs seen by veterinarians, according to Dr. Cheryl London, DVM, PhD, ACVIM, an associate dean of research and veterinary oncologist at the Cummings School of Veterinary Medicine at Tufts University.
It’s most commonly seen in the appendicular skeleton of dogs (the long limb bones). However, Dr. London explains it can also occur in the axial skeleton (consisting of the skull, vertebrae, ribs and sternum). “These are the flatter bones, like the scapula in the shoulder and the jaw,” she says. Very rarely, osteosarcoma occurs outside of the skeleton. “We call that extraskeletal osteosarcoma,” Dr. London says. “We’ve seen it in the mammary gland and the spleen.”
The growing tumor damages normal bone, making it more susceptible to breaking, and because this type of cancer is aggressive, it can rapidly metastasize, spreading to the lungs.
What Causes Osteosarcoma in Dogs?
alexsokolov/Getty Images Plus
Dr. London explains that osteosarcoma occurs primarily in large and giant breed dogs. “There is probably both a genetic and size component, meaning there are some breeds of dogs that seem to be significantly at increased risk for developing this cancer,” she says. These breeds include:
Doberman Pinschers
German Shepherd Dogs
Great Danes
Greyhounds
Labrador Retrievers
Leonbergers
Rottweilers
Scottish Deerhounds
However, it’s important to recognize that osteosarcoma can occur across various sizes and breeds. Though it’s more common in middle-aged and senior pets, this cancer can affect dogs of any age.
Signs of Osteosarcoma in Dogs
Osteosarcoma is an aggressive cancer which can metastasize (spread to the lungs) before owners notice any obvious signs in their dogs. Signs are often nonspecific and vary depending on the location of the cancer and how quickly the bone breaks down. For osteosarcoma affecting the long limb bones, such as the femur, tibia, radius, and humerus, the first signs you might see in your dog are limping or lameness.
Deborah Mandell, VMD, is a Professor and Director of Emergency Services at Matthew J. Ryan Veterinary Hospital of the University of Pennsylvania. She explains that your dog may initially respond to conservative medical therapy with non-steroidal anti-inflammatory drugs (NSAIDs). Unfortunately, it’s likely that the symptoms will typically worsen again. “The area of the tumor is also typically painful on palpation,” she says. You may even be able to see the mass or swelling, depending on which bone is involved.
“Sometimes we only see dogs after they have suffered a pathologic fracture of the area of the cancer in the leg, where they’re acutely extremely painful,” Dr. Mandell says. “If the cancer is on another bone, then pain and swelling will be a common sign, as will systemic signs like lethargy and anorexia secondary to the pain.”
Some subtle signs your dog is in pain include:
Reluctance to exercise
Loss of appetite
Irritability, aggression, or other changes in behavior
Whining, yelping, or other unusual vocalizations
Diagnosis of Osteosarcoma in Dogs
Typically, the first thing your veterinarian will do once they establish where they believe the pain is coming from is take an x-ray. “In 99% of dogs, by the time they’re lame and have failed standard treatment for a soft tissue injury, there’s usually something pretty obvious you can see,” Dr. London says. When bone cancer is present, there will typically be signs of bone destruction and sometimes new bone formation on the x-ray.
A fine needle aspiration, which removes some cells from the affected area to examine on a slide, can confirm cancer. “However, that relies upon there being enough bone destruction to get the needle in for a sample,” Dr. London says.
leaf/Getty Images Plus
While a successful fine needle aspiration can give you a diagnosis of sarcoma, most consistent with osteosarcoma, there are other types of bone cancers which vary in their malignancy. These include chondrosarcoma, fibrosarcoma, hemangiosarcoma, and histiocytic sarcoma.
A bone biopsy can provide a more definitive diagnosis, but it’s a much more involved process. “For most of our patients, we don’t end up doing a bone biopsy because they choose to go forward with amputation,” Dr. London explains.
Your veterinarian will likely also perform further testing, such as bloodwork, urinalysis, and chest x-rays, to look for signs of progression of the disease.
Treatment of Osteosarcoma in Dogs
There is currently no cure for osteosarcoma in dogs, and it’s a highly metastatic form of cancer. This means it has often spread microscopically to other body parts by the time you receive a diagnosis. “Unfortunately, we don’t have methods to detect osteosarcoma at its earliest point in the way mammograms in humans detect things when they’re just a couple of millimeters in size,” Dr. London says.
However, there are treatment options which can slow the progression of the cancer and help manage a dog’s pain. How you decide to proceed following a diagnosis is highly individualized based on various factors. “Typically, we tell owners that there’s no right or wrong decision,” Dr. London says. “Quality of life plays a really important role in decision-making, as do finances.”
Palliative Care
“The first thing we want to do is make sure there’s no obvious evidence that it has spread to the lungs, so we always take chest x-rays,” Dr. London says. “If there’s obvious spread to the lungs, it tends to be very poorly responsive to treatment (less than 10% response rate).” She explains that in these cases, veterinarians will typically recommend palliative care to keep your dog comfortable.
Even if it hasn’t spread to the lungs, you may opt for palliative care, focussing on managing the pain, since bone tumors are very painful, and regularly assessing your dog’s quality of life. This is particularly true if you have financial constraints or your dog is not a good candidate for amputation — maybe they have severe arthritis, obesity, or other illnesses.
Amputation and Chemotherapy
“For most patients, the treatment of choice is amputation followed by some form of injectable chemotherapy,” Dr. London says. While this won’t cure your dog of osteosarcoma, removing the primary tumor and administering anti-cancer drugs slows the spread of the disease and offers immediate relief from pain.
While amputation can seem a radical option, Dr. London explains that the overwhelming majority of owners are happy with their dog’s quality of life post-surgery. “Dogs don’t have the psychological challenges that we do with losing a leg, and they go back to ambulating [moving around independently] very quickly,” she says.
Sonja Birkelbach - stock.adobe.com
Chemotherapy treatment administered by an oncology specialist begins soon after surgery. “Typically, we use a chemotherapy drug called carboplatin, which is given by IV injection every three weeks in four to six treatments,” Dr. London explains. “It’s a really well-tolerated drug and doesn’t cause a lot of side effects.”
Dosing differs from human chemotherapy treatment, so your dog won’t typically suffer from nausea or diarrhea. “Some owners say their dogs feel fine with no side effects at all,” Dr. London says. “If anything, owners may say their dog feels a little tired after the treatment and maybe won’t eat for a day.”
Limb-Sparing Therapies
If your dog is not a good candidate for amputation, local radiation therapy is another treatment option for osteosarcoma. Palliative radiation can help with pain control, and high-dose stereotactic radiation works to kill off the tumor.
“Whether a dog is a good candidate for radiation and the type given depends on where the tumor is located, how much bone destruction there is, and whether the patient is at risk for fracture because the bone is very weakened from the tumor destroying it,” Dr. London explains.
Prognosis for Dogs With Osteosarcoma
Treatment for osteosarcoma in dogs is not curative, but it can markedly improve your pet’s quality of life and extend the time you have left to spend with them.
Dr. Mandell explains that with palliative care, the pain typically becomes resistant to medication after weeks to maybe a few months.
“The median survival time with amputation and chemotherapy is around 11 months,” Dr. London says. “About 25% of dogs will make it to two years. Then a much smaller amount, like 5% or less, makes it to three years after amputation.” She explains that this is because the cells that spread before amputation eventually become resistant to treatment and start growing again.
Amputating without following up with chemotherapy reduces median survival times to around three to four months, and radiation therapy offers a median survival time of about six months.
While these figures can be a helpful guide when making treatment decisions, it’s important to remember cancer is unpredictable. The main focus is typically on providing the best quality of life for however long your dog has left.
On a positive note, there’s a lot of promising research being conducted on osteosarcoma in dogs. “We’ve had some marginal successes with immune stimulant therapy, but most of the research is in its early stages right now,” Dr. London explains.
The post Osteosarcoma in Dogs: Signs, Diagnosis, Treatments appeared first on American Kennel Club.
Read more...
