Hi Wendy,
Sorry for the delayed reply. I had to wait until I was at a computer that had a blurb on Yi Yi Ren Tang on it. Here it is:
Yi Yi Ren Tang (Coix Decoction)
Gui Zhi Cinnamon Twigs
Bai Shao White Peony
Gan Cao Licourice Root
Du Huo Angelica pubescens
Yi Yi Ren Coix
Cang Zhu Black Atractylodes
Bai Zhu White Atractylodes
Dang Gui Angelica sinensis
There have been several different formulas over the centuries with this name. This one treats arthropathies due to Wind Damp invasion. The patient must be prone to Damp to be invaded by Damp. To do a proper job in reducing pain and inflammation, the formula thus also supports the Spleen to reduce Dampness production internally. Regardless the source, with prolonged Damp, obstruction of Qi and Blood flow occurs, creating pain. The formula thus also contains Blood movers.
Just as the formula is a bit of a mixed bag, so is the animal benefiting from it. Stasis (deficient) shows up as fixed lesions that are better with movement. Qi deficiency creates symptoms that are worse in the morning and from overuse. On occasion, this animal, too, is elderly.
Spleen Qi deficiency symptoms are also seen on occasion such as a low appetite, muscle wasting, soft or mucoid stools, and a pale tongue. Dampness may be manifest systemically, or as pronounced joint swelling.
The clinical finding with the highest specificity in indicating this formula is a frail and superficial pulse in even the largest dogs. They may also have a history of being worse from prolonged cold exposure.
Yi Yi Ren Tang may be especially helpful in elbow joint arthropathies of various types.
Dang Gui contributes phytoestrogen content.