Hi Kelly,
You don't mention what treatment was in play other than the coconut oil-turmeric-black pepper combination that produces the improvements by day 31. Was it just that? Or are there drugs on board?
My first instinct, given the slippery-wiry pulse, red tongue, reluctance to eat a processed diet, and the presenting GI signs would be to recommend Si Miao San. It is my first choice for GI malignancies, and its benefits would be even more likely if you drained Damp and cleared Heat with an acupuncture treatment and saw the pulse improved.
I have put dogs with poorly differentiated MCT into remission with Si Miao San and Hoxsey-Like Combination together, even when it has already met'd to the lymph nodes. Since Hoxsey is not a GI formula, I'd start with SMS first and see what happens. Note that SMS is even more likely to work if the dog was managed successfully post-op with anti-inflammatory drugs.
The only finding that is inconsistent with trying Si Miao San is the tolerance of the supplement she is on, but I would still be tempted to give it a try and see what happens.
I'd also explore a whole food vegetarian diet for the dog, since she is leaning that way herself. Note that a lot of dogs that are believed to only be tolerant of a vegetarian diet (if that is the case, and the owner is not just imposing their own lifestyle choice on the dog) turn out to handle meat just fine, when it is given in real food format. That being said, any foods that the dog has shown a clear and irrefutable intolerance to should be avoided.
The higher fiber and less accessible nutrients of the fruits and vegetables are likely less pro-inflammatory than the kibble, and thus less aggravating to an inflammatory tumor like a MCT, making her feel better and causing her to seek them out. A real-food meat-based diet (vs. using whole grains) would be an even bigger step in that direction. If the dog completely stabilizes and does very well on SMS, I would venture to say any food sensitivities are in abeyance, and that meat could be explored instead of whole grains. At that point, risk of tumor formation would go down further.
Hopefully all this helps you out. Please let us know what happens
Steve