Think Osteosarcoma Is A Death Sentence? You’ll Change Your Mind After Hearing Dennis’s Story

Update (03/26/2026): After being diagnosed at 9 years old, Dennis went on to live an incredible 6 more years cancer-free, eventually passing at 15½ from age-related causes. His family shared that while the early years were filled with fear of recurrence, that anxiety eased over time as Dennis continued to thrive.

Dennis' Story shared by Carly Anne Tonner

"One afternoon, Dennis, our 9-year-old labrador/boxer/poodle mix, developed a very mild limp in his front right leg.

A limp you would probably barely detect unless you were watching him very closely. We did, however, have a weird feeling we needed to get him checked out by our vet asap. And thank goodness we did!

Our vet was very proactive and sent him straight for X-rays to rule out any sinister causes.

To our devastation, it appeared Dennis had a bone tumour, suspected osteosarcoma, in the distal portion of his right ulnar bone.

This is the lower part of the smaller bone in his forelimb.

Now, here is where we feel (despite the horrendous news) that we were quite lucky.

It is possible for this portion of bone to be removed surgically and the leg still function and weight bare.

Our vet planned 'limb sparing' surgery for him, to avoid the need for amputation!

We figured he may need some support in his wrist area going forwards, so we discussed this with his physiotherapist.

Before his surgery, we did a full body CT scan to check for metastatic spread, which luckily was not found.

The surgery went very well!

Afterwards, he wore a supportive bandage for 3 weeks.

We also started chemotherapy, giving him 5 doses of Carboplatin.

He coped with this well, with his only side effect being sleepiness after each session.

We live in Jersey, an island near France but part of the U.K.

At the time, the Yale EGFR Vaccine was available and we were able to access this for Dennis.

"We just feel so incredibly lucky to have had such success with him"

We gave him his first dose a few weeks after his last chemotherapy dose.

And we feel so lucky to have accessed this vaccine because Dennis is now 3 years post-diagnosis!

It was on January 31st, 2020, that he was diagnosed.

He made his 12th birthday.

He even has full function of his leg, no lameness, no pain... You would never know what he had been through, or know he had a portion of bone missing from his leg!"

Update: June 2025

We got an update from Carly last month: "He is an old boy these days at 14.5 years old, so he has been getting weaker on his back legs. But otherwise, he is doing great for his age, and

He still never had any signs of cancer returning to this day, 5 years later.

We are still so very grateful!"

"We just feel so incredibly lucky to have had such success with him, and wanted to share this so people know there is hope.

Knowing that the vaccine is becoming more accessible again makes us so happy. As we are certain this helped Dennis!

Thanks again for allowing us to share his story."

(If you are interested in this treatment, please download the EGFR/HER2 Vaccine Immunotherapy FAQ here.)

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