Hi there! Yes, I do use the same formulas to approach renal disease in horses. If the pulse is very weak, you're looking at tonification using Rehmannia Eight (in robust amounts). If the pulse is surprisingly strong, then you're looking potentially at a Shao Yang disharmony. You would sedate GB points and if the pulse improved, then you'd want to use Xiao Chai Hu Tang with Qin Jiao added (you can buy the latter from A Time to Heal as a separate herb). Mix about 15g Qin Jiao per 100g XCHT. If the horse is Kidney Qi deficient, then points like BL 23, KI 3 or KI 7 should help.
Hopefully this helps you out!
Steve