My dog has a high-grade mast cell tumor with incomplete margins. What now?
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!
Updated on September 23, 2025