Elvish Medicine?

[Nar]

Luthien and Huan, hound of Valinor, use elvish medicine -- not to mention elf-dog medicine -- to save Beren --the following is from the long poem The Lay of Lethian in The Lays of Beleriand, HoME 3

Then Huan came and bore a leaf,/of all the herbs of healing chief,/ ... with broad and hoary blade./ ... The powers of all grasses Huan knew/ ... while Luthien murmuring in the shade/ the staunching song, that Elvish wives/ long years had sung in those sad lives/ of war and weapons, wove o'er him.