A Primer on Osteosarcoma

One of the most disheartening diagnoses I must deliver is that of osteosarcoma, a painful and aggressive form of bone cancer that has an affinity for growing within the leg bones of large and giant- breed dogs. I must explain to my client that, while I have the ability to improve upon their best buddy’s quality of life for a period of time, with rare exception, a cure will not be possible. By the time the dog begins favoring the painful leg, microscopic cancer cells will have already spread, typically to the lungs or other bony sites. Sooner or later these tiny clusters of cells will grow into metastatic tumors that will ultimately become life-ending.

The lameness caused by osteosarcoma is typically mild at the onset, but then progresses over time. The level of pain can morph quickly from mild to severe if the diseased bone suddenly develops a crack (microfracture) or a full on bony break.

Surgical therapy

The most commonly recommended treatment for osteoscarcoma is amputation (surgical removal) of the affected limb. For the uninitiated, amputation may seem like an overwhelmingly radical next step. Those experienced with three-legged dogs know that most of them adapt quickly and amazingly well- both physically and emotionally- to their newfound tripod status. The caveat here is that in order for amputation to be successful, the dog’s other three limbs must be strong and sturdy and free of disease such as significant arthritis.

Perhaps you are wondering, why perform such an aggressive surgery, when the result will not be curative? The answer is simple. Osteosarcoma is a dreadfully painful disease. The primary goal of therapy is elimination of that pain with restoration of a good quality of life.  Amputation has the ability to accomplish both of these objectives.

Is amputation the right choice for every patient with osteosarcoma? No way! The elderly German Shepherd with severe arthritis in multiple joints is very unlikely to adapt well to life as a three-legged dog. Conversely, the older German Shorthaired Pointer who has been a lean, mean, running machine will very likely be back to all his usual tricks within a couple of weeks following surgery.

If ever you must consider amputation for your dog it is imperative that together, you and your veterinarian do some significant soul searching to determine if this surgery makes good sense. One of my favorite client support websites is Tripawds, a community of people who have “been there, done that” and can offer a whole lot of experiential wisdom pertaining to the decision of whether or not to proceed with limb amputation.

Another surgical option for the treatment of osteosarcoma is referred to as limb-sparing. This involves removal of the portion of the bone that contains the tumor without removal of the entire limb. Not all dogs are appropriate candidates for this surgery- the tumor must be located in just the right spot within the bone. Compared to amputation, limb-sparing surgery is technically more difficult, significantly more expensive and requires a longer period of recovery and confinement. Limb-sparing surgery is certainly worthy of discussion as an alternative to amputation.

Chemotherapy

Chemotherapy (the administration of cancer fighting drugs) is recommended as a treatment only following surgery. Chemotherapy can stave off growth of the microscopic metastasis- those cancer cells that have already managed to spread by the time of diagnosis. As a “stand alone” therapy (administered without surgery), it is woefully ineffective at battling the primary cancerous growth. Approximately half of the dogs treated with surgery followed by chemotherapy will be alive one year following diagnosis; approximately 25% will be alive two years following diagnosis, and every once in a great while, a cure will be achieved. Compare this to surgery alone (no chemotherapy)- the average survival time is approximately six months.

The good news is that dogs tend to tolerate chemotherapy far better than we do. Rarely do they experience significant hair loss, and vomiting and loss of appetite tend to be the exception rather than the rule. If this were not the case, I’m doubtful that many veterinarians would be willing to administer chemotherapy drugs.

Other treatment options

When surgery is not an option, other therapies may effectively reduce the pain associated with osteosarcoma. A few treatments with radiation therapy can do wonders and nonsteroidal antiinflammatory medications, narcotics, and a class of drugs called biphosphanates are all reasonable options for mitigating discomfort and enhancing quality of life.

Research to develop an osteosarcoma vaccine is currently underway at the University of Pennsylvania School of Veterinary Medicine. The hope is that this vaccine will stimulate the immune system to hone in on cancer cells containing a specific genetic marker found in approximately 40 to 50 percent of dogs with osteosarcoma. I will keep you posted on any new developments. In the meantime, if your dog has been diagnosed with osteosarcoma and you happen to live near Philly, consider enrolling in this clinical trial.

Prevention

Several dog breeds are highly predisposed to developing osteosarcoma. Breeders of Rottweilers, Irish Wolfhounds, Great Danes, Saint Bernards, Doberman Pinschers, Labrador Retrievers, Golden Retrievers, Greyhounds, Samoyeds, Akitas, and Siberian Huskies should pay close attention to osteosarcoma incidence within their lines with hopes of altering the inheritance pattern of this deadly disease.

Some fascinating research involving Rottweilers documented that individuals neutered before one year of age had significantly increased risk of developing osteosarcoma later in life. This information is truly compelling and gives rise to a number of other questions. Does this data apply to other breeds? Does the timing of neutering affect development of other types of cancer? When is the ideal time to neuter Rottweilers and other large and giant breeds? My hope is that future research will begin to answer some of these questions.

Have you ever cared for a dog with osteosarcoma? If so, what did you choose to do?

Best wishes,

Nancy Kay, DVM

Diplomate, American College of Veterinary Internal Medicine
Author of Speaking for Spot: Be the Advocate Your Dog Needs to Live a Happy, Healthy, Longer Life
Author of Your Dog’s Best Health: A Dozen Reasonable Things to Expect From Your Vet
Recipient, Leo K. Bustad Companion Animal Veterinarian of the Year Award
Recipient, American Animal Hospital Association Animal Welfare and Humane Ethics Award
Recipient, Dog Writers Association of America Award for Best Blog
Recipient, Eukanuba Canine Health Award
Recipient, AKC Club Publication Excellence Award
Become a Fan of Speaking for Spot on Facebook

Please visit http://www.speakingforspot.com to read excerpts from Speaking for Spot and Your Dog’s Best Health.   There you will also find “Advocacy Aids”- helpful health forms you can download and use for your own dog, and a collection of published articles on advocating for your pet’s health. Speaking for Spot and Your Dog’s Best Health are available at www.speakingforspot.com, Amazon.com, local bookstores, and your favorite online book seller.

 

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14 Responses to “A Primer on Osteosarcoma”

  1. Liliana says:

    Dear Nancy,

    My precious girl Sasha (who just turned 12 a few weeks ago), was diagnosed with OSA on March 6, 2012. After much research, my husband and I decided to proceed with amputation, followed by Chemo. We also enrolled her in the Mason Bone Cancer Study at UPenn. Starting in July, we drove her up to Philly, at 3 week intervals, to receive the vaccine. I am so happy to report that Sasha is doing wonderful. I have a little blog where I post updates and also share stories/updates of other dogs in this clinical trial. These dogs needed to test positive for her2/neu gene. It seems this gene is very aggressive. Even the TV show Parenthood, recently had an episode where a female was diagnosed with breast cancer, and after the tests came back it was her2/neu and it was mentioned on the show as well, of how aggressive this gene is.

    ~Liliana

    PS. In all the research that we did, we came across evidence that a spayed or neutered dog is at higher risk for OSA, among other cancers.

  2. Barb Arkin says:

    Nancy, my 12 year old Giant Schnauzer, Duchess, was diagnosed in August with toe cancer which is too common in the breed. My regular vet did initial xrays and then I went to VRCC’s oncology department. CSU has been doing a lot of studies of this and the person at VRCC was in charge of those studies. Looking at the x-rays (and my vet had included some of the chest which showed no incidence) she basically said there was not much we could do but pain management. At Duchess’ age amputation did not make sense, nor did chemo. We went home and I took out Speaking for Spot and made a decision: we would try the pain management (she is on 3 different pill two times each day) and see what would come. When she refused food, did not boss my German Shepherd around, and did not want to help feed the horses I would put her down. The tech at VRCC called my vet that week thinking they needed to send me a condolence card – nope. I went to steward a major out of state show in Idaho in September and Duchess did fine in the kennel. Last month we had dog guests (a standard poodle and a mini ) for 12 days and Duchess put them in line. I did learn that she got hot, probably a reaction to the meds) and would wake me two or three times each night, so I clippered her coat and we now sleep through the night. Yes, she has her “three legged moments” about two or three times per week, but even then she goes to check on the horses with me. She ran the three year old poodle down for a toy Duchess decided she wanted. How much longer? I don’t know. I have talked to breeders about a puppy and will probably get one this spring as the GSD loves a play mate. At least we can make decisions for our 4-legged pals to help them “over the rainbow bridge” – and I will do this.
    Thanks for the discussion.

    Barb

  3. Rox says:

    FYI, you might want to also look at this article:

    http://www.veterinarypracticenews.com/vet-practice-news-columns/bond-beyond/is-early-neutering-hurting-pets.aspx

    It cites “a retrospective study published in 1999 by Ware, et al, that found a five times greater risk of cardiac hemangiosarcoma in spayed vs. intact female dogs…. Ware’s study also found a 2.4 times greater risk of hemangiosarcoma in neutered dogs as compared to intact males.”

    The article also notes the “2002 epidemiological study of 3,218 dogs done by Cooley and Glickman, et al, found that those neutered before age 1 had a significantly increased chance of developing osteosarcoma.”

  4. Joanne Sweeney says:

    My field trial English Springer Spaniel Rascal was diagnosed just shy of his 11th birthday. He started to limp (hind leg) in July and when it didn’t resolve after about a week – took him into the vet (who had cared for him and my other 2 Springers from pups.) She x-rayed and noted that she couldn’t see any signs of osteosarcoma, but thought that might be the likely cause even though not common in the breed. We discussed the disease briefly, but took a wait and see attitude. Within a month, I noticed a bulge and back to the vet she confirmed the diagnosis.

    She explained the options – but noted that with his age, and some signs of arthritis in his back, he was probably not a good candidate for amputation. She did explain as Dr. Kay does in the article that the cancer would have already spread and could not be cured so other options like chemo would only delay the inevitable and might compromise the quality of the time he had left. Eventually, the bone would become too weak and break. I was upset but understood and wanted to do the best for my buddy.

    Based on his age and in spite of still being in good physical condition I decided to forego any radical treatment and let Rascal have whatever fun he could until he wasn’t comfortable. Within a month the bone did break I made a homemade splint to support his leg and remarkably he still trotted around the yard holding his leg up without much trouble. I made an appointment for the next week to say goodbye. My wonderful vet advised that he didn’t know that he had that appointment, so enjoy his last week. It only was about two months from initial symptoms.

    One of the hardest things I’ve ever done taking that ride to the vet. He enjoyed a final walk around their grounds and then I took him in to say goodbye.

  5. Carlie says:

    My male husky was diagnosed last year and went through surgery and 15 treatments of radiation and a year later he is doing very well. He will be 13 on Fed 10th and still runs with me while biking . I would never have had his leg amputated at his age of 12. He is doing great and I would do the surgery and radiation again if I had a dog in great shape and good health again.

  6. Laura Michel says:

    Our golden retriever was diagnosed when he was nine. April of 2013 will be his two year amputation date. He had six rounds of chemo and is now on daily chemo and metacam. He has not lost his zest for life although at times he is slowing down. He still chases our children, chases balls, etc. I have been feeding him zero grain dog food and cooking turkeys, chickens, etc. for him every day. He also eats greek yogurt everyday with omega three. in his food i cook kale and brocolli and mushrooms and ensure he has a teaspoon of turmeric everyday. I am not sure if any of this is working. I thank the veterinary care he received although the news was devastating to us.

  7. Helen says:

    I don’t think i have words to describe how i feel about all this. I never thought in my years i would go through this. I have an Akita that was diagnosed in May and we have been through the chemo without amputation. She is 11 now and had torn both ACLs, even survived bloat. She still has a strong spirit even though now she is experiencing bone pain. I go weekly to the vet clinic several times a week between both dogs trying to keep them both living pain free and happy. My other girl tore both ACLs at the same time and has had surgery on both.
    I have spent time researching and talking to quite a few owners going through this disease. So disheartening to think you cannot prevent this from happening to your pet, no matter how well you take care of them. We have tried everything from a raw diet to holistic treatments. What i have learned has only been from her. Her strength and spirit through all this is incredible. I pray every day i am doing the right thing for her and for god to give her the strength to keep living. My prayers to all who have to go through this experience.

  8. Fiona Iwan says:

    Dr. Kay, yes we were faced with the diagnosis of OSA a little over a year ago when our vet told us that our beautiful two year old white lab puppy had the dreaded disease. When faced with amputation or limb sparing surgery we chose limb sparing surgery. 5 months after the diagnosis we lost our beautiful Misty girls despite all our efforts and the efforts of the doctors at UC Davis Veterinary Hospital. Would we do that particular surgery again? I don’t know but I do know if faced with OSA again we would go to the ends of the earth to heal our beloved family member. Without the help of the Tripawds community this past year I don’t know what I would have done.

  9. Jenny says:

    I chose amputation for my dane after he was diagnosed with a hystiocytic sarcoma in the knee. He was not an ideal candidate for amputation but with our neurologist’s blessings and knowing what a strong will our dane possessed, we gave it a go.
    Our dane had severe cervical vertebral instability- aka wobblers syndrome and had his spine surgically stabilized 4 times. He had also endured 3 acl surgeries and 1 hardware removal- which resulted in the discovery of the cancer. So we took a dane with 1 good front leg, 1 front leg with some nerve damage and slight lameness, 1 repaired knee in a back leg and then removed a back leg. Miraculously, he adapted. He refused to use his wheel cart and learned to hop on his own. I chose to use holistic meds in lieu of chemo.
    After 17 months, I made the tearful decision to lay him to rest as his spinal problems were progressing from all the strain of hopping on 3 legs. His necropsy showed no return of cancer anywhere in his body. I do believe we stopped the spread of the cancer through the use of artemisinin and curcumin.
    For this dog, I would do it all again but it is not something that I would take on for most dogs. Moving forward, we have decided that we will not go the amputation route with any of the other dogs in our current pack due to the fact that nearly all have had acl surgeries and are increasing in age. Tough decisions.

  10. Kimberley says:

    I have lost 2 dogs to this particular cancer – a rottie and rottie mix (one male and one female). I chose different treatment paths for each. For one, I chose amputation followed by chemo. For the other, I chose radiation. Neither of them survived more than 6-8 months after their diagnosis, even with the treatments. Because of that and the significant costs involved, I have serious reservations about whether or not I would pursue any treatment (other than mitigation of pain) if I was to have another dog develop osteosarcoma. It’s a tough call and one I hope I never have to make again.

  11. Kathy says:

    I lost my heart dog at the age of 11 due to OSA. She was a beautiful Rottie named Chelsea. It was in her lower right jaw and I opted to have it removed. She also went through chemo. She was a trooper and did well. I think the total time from dx was 8 months. I wrote about it on my blog, it started in August of 2010 I think. If I had to do it all over again, I would choose the same route. She wasn’t ready to go. The morning she refused her pain meds she told me she was ready to go and I took her to UT where she had been in treatment for her final farewell.
    http://followyourblissfarm.blogspot.com/

    It is a dreadful disease, thank you for writing about it and educating people.

  12. Jeanette says:

    Thanks for sharing this, Dr. Kay. I’ve been fortunate that none of my Rottweilers have suffered this disease, but I’ve known plenty of owners whose dogs have.

    I’m curious about the research (and its been shared in my Rottweiler community before) because I have a shelter rescue that is (supposedly) half-lab but he’s definitely in the large breed category (80# and very lean).

    He was neutered before we could bring him home (at 3 months) so I’m wondering if research like this would have any future impact on the requirement that pets be altered before they’re adopted? I completely understand why that is, but I also want to give every dog I bring into our family a fighting chance of living a long, healthy life.

    Thanks, as always, for sharing your expertise in a way that connects to those of us without veterinary degrees!

    Jeanette

  13. Mary James says:

    My 150# Anatolian Shepherd, Cemil, was suspected of having developed osteosarcoma and after spending an entire weekend learning from the folks at Tripawds, I opted for amputation. The confirming diagnosis followed the surgery. We went the holistic route afterward and it has been successful so far. Mr. Miracle Dog is almost four years past his surgery and is still enjoying life.

  14. We’ve had Danes for 30 years and have seen the best and most horrific of outcomes. My first Dane was dxed with this brutal disease at 8.5. yrs. Due to availability of a limbspare surgery research project at Co. State University in nearby Ft. Collins we chose limb spare and chemo. Emmie died almost exactly 3 years later from Lymphosarcoma, after enjoying 2+ yrs hiking with us, cruciate issues finally slowed her down. She may have been one of those who was cured….there was no trace of osteo upon necropsy. She tolerated chemo quite well physically, tho there were certainly psycho/emotional issues, even for this very stoic, lovely dog. But a few months past tx, she did regain most of her confidence.
    My heartdog and mentor and DAne #9 Ellie had the opposite experience. Dxed. just prior to her 6th birthday, she was dead in 5.5 months, despite amputation and starting chemo. The chemo left her with horrific, bloody sores in her mouth, her fragile psyche was less able to bear the treatment. We amputated, believing that her athleticism, love of speed and high drive would enable her to recover from the surgery, but it left her horribly depressed and painful, a mystery even to the vets who treated her. Stoic to the end, she struggled to maintain the profound connection we had slowly forged, as I begged her over and over…don’t go, please….don’t go.But go she did, the cancer spread to her spine, and this fast, brilliant dog, who ran and ran for the sheer joy of it, was left with paralyzed hindquarters and in untreatable pain within 72 hours. It was perhaps the most traumatic experience of my life.
    I’d trained and shown for obedience and taught on and off. Ellie’s view of the world was like nothing I’d ever lived with, often distant, even hostile, but her persistent attempts to engage me, sporadic as they were, left me looking for answers and finally I learned to see through her eyes that for this brave dog, the world was not a safe place. We learned together, me to honor her rfears and apply what she taught me to what is a now a behavior practice which seems to focus on reactive and fearful dogs. She learned to trust me, to give me her heart and soul, knowing I had her back, always and that I would keep her safe.
    In the end, I failed, of course, to protect her from this damned disease and and its emotional and and physical pain. I can only hope that what she taught me in her all too short life will help the dogs I now work with, because it is still her eyes I see and her courage I remember when I look into theirs.
    Thank you for this honest, compassionate posting. I can only hope that we will some day be able to find a real cure for this terrible, terrible disease. Thanks again for posting about it.