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My dog has a high-grade mast cell tumor with incomplete margins. What now?

Updated On September 23rd, 2025

Pet's info: Dog | Mixed Breed | Female | spayed | 9 years and 10 months old | 56 lbs

My baby diagnosed today, Mast Cell Tumor grade II,- High Grade (kiupel system) Mitiotic count greater than 30. Margins appears incomplete Neoplasticism MCell present at nearest submitted ventrilateral margin. My vet didn’t give me clear answer what we can do. What do you recommend to do? Re-surgery (MCT at right ear) cut off ear? Quimo? Or don’t fight anymore? Please help and kindly advise,, I am just ok to hear your thoughts.

2 Answers

Most Helpful Answer

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Answered By Anna M., DVM

Veterinarian

Published on May 4th, 2021

I’m sorry to hear about Tsunami’s diagnosis. MCTs are quite common in dogs, and unfortunately due to the cell distribution around the primary tumor, incomplete margins are common. If you want to be confident you’re pursuing the best options for the best prognosis, I recommend asking your vet for an oncologist referral. A veterinary oncologist will be the best specialist to be able to present all the options and their given pros & cons, and they have access to chemo medications that most primary vets don’t carry. If you choose not to pursue referral, then I recommend reaching out to your vet again to discuss the next step. If this were my case, I would probably recommend sampling Tsunami’s lymph nodes with a needle to look for evidence of regional metastasis, and based on those findings discuss if a second surgery is appropriate. Hope this helps!

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    Answered By Lauren Jones VMD

    Veterinarian

    Published on July 15th, 2021

    I'm so sorry to hear that you and Tsunami have been through so much lately. Unfortunately, high grade mast cell tumors have a pretty guarded prognosis - a survival time of 4 months is the average with surgery alone. From my research, metastasis to the lymph nodes does not markedly impact expected survival times with high grade tumors, but it would change things if she had a low grade tumor. Chemotherapy (including Palladia) may help to slightly prolong her survival, but there are so many variables at play (i.e. specific mutations in her tumor, as well as Tsunami's currently quality of life) that it's hard to comment more specifically. If you want to do everything possible, I'd recommend consulting a veterinary oncologist. Even then, they won't be able to cure her cancer, but will try to manage it to prolong her survival time while maintaining her quality of life. Ultimately, try to make any decisions based on Tsunami's quality of life. This resource has a lot of good information with respect to evaluating her quality of life: https://vet.osu.edu/vmc/sites/default/files/import/assets/pdf/hospital/companionAnimals/HonoringtheBond/HowDoIKnowWhen.pdf. Best of luck with everything. I hope that everything goes as well as possible.

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