Hi there,
I'd rule out Blood deficiency (essentially a circulatory issue) first, given the breed and description. Fish oil, melatonin, and thyroid are all commonly helpful in Blood deficient dogs. If any of these aided the dog, then it supports Blood deficiency.
The Bladder channel distribution and deep wiry pulse indicate that the reason for the poor circulation might be a Tai Yang (Wind) invasion, whether or not that is showing itself. It could also just be that the Tai Yang layer is 'furthest out' from the body core, and therefore most compromised in the way of peripheral circulation. At any rate, simple Blood tonics won't suffice, given the deep wiry forceful pulse.
Recently I've greatly accelerated hairgrowth in a woman with alopecia universalis using Xue Fu Zhu Yu Tang. It has both tonic and moving properties.
Failing that, or if there is low back stiffness and hind end issues, Du Huo Ji Sheng Tang is a good consideration.
Sedation of BL 40, if it relieves the wiry nature of the pulse, suggests DHJST is the better place to start. Otherwise, I'd try XFZYT.
Good luck!
Steve