Hi there,
The lack of response to raw tells us this is not likely to be a Damp case. The redness of the tongue and coarseness of the coat tell us there is a lot of Heat despite the chilliness, suggesting the latter is probably due to poor skin circulation. If pure Blood tonics haven't helped, and if the onset was associated with papules and skin lesions, then it suggests there may be an unresolved folliculitis promoting the problem, accompanied by Blood stasis.
I've started some of these animals on Qing Ying Tang, switching to more pure Blood tonics or Si Wu Xiao Feng Yin as cases plateau after their initial response.
Hopefully Qing Ying Tang gets things going for you
Steve