Hi Wanda,
You may want to just stick with Si Miao San and Hoxsey. The 'reaction' to XFZYT is really just a vascular incompatibility. Because it pushes the blood supply to the skin, a dog with subclinical subacute to acute skin inflammation tendencies will flare up on it, whereas a very chronic skin problem (that by definition has too poor a blood supply) won't.
So, taking the lead from the dog (and the full pulse), you need an anti-cancer protocol that happens to pull blood away from the skin. That makes me think of Hoxsey and SMS together. I'd give them a try. Hoxsey is a good moving formula, so it can be used in cases with some Stasis in the tongue like this one.
Let us know how it goes!
Steve