Canine Osteosarcoma, Our Experience Part I

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Since Maggie was diagnosed with osteosarcoma (OSA) last month, I’ve done as much reading as I could about the disease. Having had two female black labs who both developed it, I also wondered about breed propensity for OSA. And finally, I looked at treatments recommended – particularly the Stereotactic RadioSurgery we are doing with Maggie. Needless to say, I have a lot to write, so this will likely turn into multiple posts.

Note: Our intent is only to inform and share our experiences. We are NOT veterinarians and nothing we say should be taken as veterinary advice. If you have any concerns about your own dog, see your vet.

maggie canine osteo
Our first indication that something was wrong with Maggie manifested itself the same way it did with Becca…a simple limp in the affected limb. Both Becca and Maggie developed OSA in the left front limb – Becca in the shoulder and Maggie in the foreleg. Becca had many orthopedic problems, so I didn’t do much at first other than increase her normal dose of painkillers and rested her. When it didn’t improve we went off to the vet. The vet was able to discern fairly easily from Becca’s xrays alone that it was OSA as there is a fairly characteristic pattern which we will talk about.
With Maggie, we knew she had arthritis in her front legs, so we did the same at first, increased her arthritis medication, added a few pain killers and rested her. When she didn’t improve after a several days of rest, we went to the vet. After a few more agonizing days of waiting for a definitive diagnosis, we were finally told it was OSA. I’ll talk more about diagnostic methods in our next post.

From this point, the treatment for our two girls diverged. We will discuss treatment plans, but first let’s take a deeper look at OSA, what it is, what may cause it and how it affects our dogs.
Osteosarcoma is cancer of the bone. It is the most common bone tumor present in dogs, accounting for 85% of all malignancies in the skeletal system. This cancer normally affects the dog’s limbs. The tumor originates within the bone and destroys it from the inside out.1. OSA is highly aggressive and in 90% of cases has micro-metastasized to other parts of the body before it is even diagnosed.2. OSA metastasis is termed hematogenous, or carried through the blood to the lungs, other bones and possibly the thyroid. Long term prognosis is poor.
OSA develops deep in the bone and creates a great deal of pain as the tumor grows outwardly, destroying the bone as the tumor grows. The bone is weakened as healthy bone is replaced by the tumor, so an immediate concern is a pathogenic fracture of the affected limb. A fracture of this type will not heal, so care must be taken for your dog’s safety during this time.
Our Becca used to love jumping off the landing from the kitchen into the family room – only two steps, but I was so afraid she would hurt herself, we built a ramp. Maggie loves to jump out of the back of our station wagon – onto the concrete driveway. I’m struggling with getting her to use the steps we’ve gotten. She’s good about going up the steps, but not so good about coming down.
While there is no specific research to support a genetic link by breed, Rottweilers are by far the breed most susceptible. It occurs most frequently in large breed dogs, with dogs over 80 pounds sixty times more likely to develop OSA than dogs weighing under 75lbs.3. It occurs more frequently in males than females. It has also been noted that it occurs most frequently near growth plates and there is some speculation that diets which encourage rapid growth in puppies may be a risk factor.4.
There have been studies examining early spay/neutering as a factor. In a study of Rottweilers, it was shown that male and female Rottweilers with the shortest lifetime gonadal exposure had the highest risk for bone sarcoma.5. In addition, dogs with OSA have been found to have aberrations of the p53 tumor suppressor gene (whatever that is). Other risk factors include exposure to ionizing radiation, chemical carcinogens, foreign bodies, (such as bullets or bone transplants), and pre-existing fractures or other skeletal problems. 6.
I have no idea how or why either of our girls developed OSA. Since both of them came to us late in their lives, I don’t know of any prior exposure to these risk factors – other than being large breeds. At this point, the “why” doesn’t really matter, what matters is what are we going to do about it. Next up: Diagnostic methods and treatment options.


1. Osteosarcoma | AKC Canine Health Foundation
2. Osteosarcoma (bone cancer)
3. Osteosarcoma in Dogs
4. Osteosarcoma (bone cancer)
5. Endogenous Gonadal Hormone Exposure and Bone Sarcoma Risk
6. Osteosarcoma

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  1. Your experiences sound so similar to ours, down to it being in the left forelimb… And, like you, we initially thought that K had aggravated her “bad” paw (she had one toe amputated from that paw a year earlier). Fortunately, we had a routine vet appt for something else, when our vet astutely sneaked K into the back for an xray. That told the story.

    We did the same as you, putting ramps everywhere we could to help avoid a pathological fracture. My vet also suggested carrying a “SAM” cast with us when hiking just in case…. We never needed it, thank goodness.

    Thanks for writing about this. I know it’s a tough subject.
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  2. that are the posts I only can read with tears in my eyes, but they are very, very important… I’ve learnt a lot today and I’m grateful that you share this informations with me. POTP for Maggie and hugs to you
    easy rider recently posted…easyblog SHOP TILL YOU DROPMy Profile

  3. What an important post, but such a horrible condition. POTP Maggie.
    Earl Lover recently posted…5 Tips To Snap Your Dog Nicely On CameraMy Profile

  4. TY for the info.

  5. Thank you for information, so useful for many….dog kisses to Miss Maggie May….

  6. I’m fighting back tears as I write this, so if I don’t make sense please forgive me….
    After Callie had healed from her first ACL surgery, she wouldn’t let me help her out of the car. I would try, but she would dig in until I gave up. But the second ACL surgery made her a bit unsure of her own footing, so she allowed me to help…
    We have a Chevy Impala, so Callie and Shadow have always shared the back seat. I’m not strong enough to lift her by myself, so I used one of the puppy blankets that I kept in Ducky’s travel crate to use as a sling. And, since the concrete driveway is surrounded by grass, I just parked in the grass so she would have a softer place to “land”. Eventually, as she became more sure of her footing, I just used my right arm as the sling to help her out of the car. I was still using that “approach” when I brought her to the vet on Monday morning. She knew I would always be there to help her, and I could tell from her eyes that she appreciated that help. I miss my sweet girl soooo much.
    Callie, Shadow, and Ducky’s Mom recently posted…My Heart Is Broken My Profile

    • Thanks for the tips – Maggie is still fearful sometimes, so attempts to hold her are not welcome. I fear even jumping onto the grass may be too much pressure.
      mkob recently posted…Canine Osteosarcoma, Our Experience Part IMy Profile

  7. I guess the sling would be a bit difficult to use for Maggie since the cancer is in her front leg. But, is there any way you can park the car in the grass? Or, even just the back end of the car, so Maggie can “land” on the grass instead of concrete?
    Callie, Shadow, and Ducky’s Mom recently posted…My Heart Is Broken My Profile

  8. While I’m so heartbroken about Maggie’s situation, I did want to thank you for sharing your experience and information about it. It can’t be easy for you so please know I continue to keep you all in my thoughts and prayers.
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  9. Thank you for sharing. This is such a scary situation, but something I’m happy to be learning more about. I know that I could never be truly prepared for this, I appreciate you taking the time to share what you know. Hugs to all of you.
    Kimberly Gauthier recently posted…5 Reasons to Order from Raw Paws Pet FoodMy Profile

    • Thanks Kimberly. Even though we’ve been through it with Becca, I’ve spent a lot more time learning about it this time and feel better prepared.
      mkob recently posted…Canine Osteosarcoma, Our Experience Part IMy Profile

  10. When going through cancer or other illnesses, it is a great help to me to be able to find personal stories of it, so I think it’s such a great thing you are writing about this. Especially since it has to be difficult when you’re in the middle of it all.
    Sheba had been limping too (back leg which is not where her arthritis was diagnosed), and I worried, but thank goodness for us rest and pain killers did the trick. We still watch her carefully for any escalation though.
    Cancer really sucks, but I am so glad for you that treatment has been helping Maggie, and I hope you get a lot more time with her.
    Jan K recently posted…#52Snapshots of Life – “Sleepy”My Profile

  11. We all go in for our annual exams next week and Mom is always afraid they will find something with Katie. She had a front left leg limp for several years, but Rejenease cured it! It was never found to be cancer causing it. Cancer is so ugly, we hope Maggie can feel well for a long time with her treatments.
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  12. Thank you for sharing all the knowledge you are picking up. This is not a pleasant situation at all, but I’m thankful for the opportunity to learn more about it. BIG HUGS to the entire SlimDoggy family, especially Maggie.
    Jessica Shipman recently posted…Happy National Dog Day!My Profile

  13. Thank you for sharing. So sorry to hear you’re going through it.
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  14. If there is one thing that we do know about cancer, it doesn’t discriminate. I am so sorry that you’ve had to deal with it twice. I’m sending POTP to Maggie. ♥
    M. K. Clinton recently posted… for MomMy Profile

  15. I find that all our guys accept(ed) ramps much mor readily than steps. We had one for going in and about of the house and we made one for getting in and out of the vehicle also. I think there is much higher chance of compliance with ramps.
    Jana Rade recently posted…My Love Is Still Sleeping At My Feet: An Unexpected UpdateMy Profile

    • My problem with ramps is they are so heavy…tough to take the dogs to the park every day and deal with it.
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      • Habituation … 😉 Yes, it’s pain but one gets used to it. We used one for Jasmine at all times; it just becomes part of the process, nobody even thinks about it any more. Depending on how high it is in and out of the vehicle, I saw some made mostly from aluminum, fairly light; for us it would have been too short (too steep of incline so we had to make our own).
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  16. The only experience with K9 cancer I’ve had so far was Missy’s diagnosis with thyroid cancer last year. We were extremely lucky that the tumor was removable and no metastasis had formed in her body. We are crossing our paws that it won’t come back.
    OSA sounds very scary. Thank you for sharing your findings with us. Maggie girl continues to be in my daily thoughts.
    Barbara Rivers recently posted…Myth Buster: Garlic IS good for dogs, after all!My Profile

  17. Thank you for this well written article, I’m sorry you have to go through this at all but to share your experience with others may help others make decisions that they wouldn’t know how to make with their own pets it this would ever arise in them.
    Sand Spring Chesapeakes recently posted…Tunnel And Truck Puppy Fitness~FitDog FridayMy Profile

  18. Oh my gosh I’m so sorry to hear about Maggie. She is the second Blog Pawser pup who was dx’d with osteo this year (the other being Lucas, pup of Maggie from OhMyDog.

    There are no right or wrong choices when it comes to osteosarcoma. Whether you choose to amputate as we did for our Jerry, do palliative care or explore other options like SRT, the Tripawds Community is here for you. Our members take all sorts of paths, with no judgement from others, just support. Please don’t hesitate to contact us if you need anything at all OK? -Rene, Jim, Wyatt Ray, Spirit Jerry & the Tripawds Nation
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