Hi Llewanda,
I'm glad you've made significant strides with this dog, as originally hoped. For the current epistaxis, Yunnan Bai Yao is fine to try and use anytime there is a bleed.
The response ot the herbs confirms the dog has a Shao Yang disharmony with Blood deficiency. Another formula to manage that is Halscion (Chai Hu Jia Long Gu Mu Li Tang plus Yi Guan Jian). The nose belongs to the Stomach channel for the most part, so Stomach Heat can be reflected as epistaxis. If the dog is not particularly Damp, then Stomach Heat can be assumed to arise instead from Dryness (the quintessential Yang Ming pathogen). YGJ treats Yang Ming dryness and associated Heat, and supports the continued formation of Blood.
Chai Hu Jia Long Gu Mu Li Tang is a good potential choice as well. It helps internalize Yang. Ascendant Yang can likewise cause nose bleeds (since the Governing Vessel is likewise intimately associated with the nose). Since Yang is fully emerged on the surface and the dog is still a little Blood deficient, we may be seeing a few weeks early what would normally happen in July (a surfeit of Yang and a lack of Yin on the upper and outer body surface). In that case, CHJLGMLT + YGJ should help
Lastly, for some dogs with obstinate nasal lesions that are bleeding, I've used Xue Fu Zhu Yu Tang, but this doesn't seem like that situation. Still, it's a consideration.
Hopefully these ideas help you out. I still anticipate you can completely cure this dog.
Steve