A. I am sorry to hear your dog is so unwell, it is important now to monitor her quality of life and ensure she is kept comfortable at all times and is not allowed to suffer. Monitor closely her ability to swallow and drink without difficulty and is able to rest comfortably without pain. Such a large tumor is likely to cause significant difficulties if it continues to grow. There is a helpful worksheet to guide palliative care decisions: http://vet.osu.edu/assets/pdf/hospital/companionAnimals/HonoringtheBond/HowDoIKnowWhen.pdf
A. Median survival times for dogs with oral melanoma treated with surgery are approximately 17 to 18, 5 to 6, and 3 months with stage I, II, and III disease, respectively.
I do not know what stage your dog was diagnosed with, but 4 cm on the base of the dog is very big, i would say that without surgery you shouldn't expect more than 2 months.
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