Not sure if you are looking for ideas or not, but here are a couple :).

leeches are actually good for circulation problems in the limbs, even in modern times they get used when reattaching fingers/ears/etc (evidentally plastic surgery sometimes too), tissue transplants, etc to help maintain circulation while it's healing. You might want to add another type of leech to help with paralysis or limb reattachment?

Certain types of maggots will eat dead tissue from a wound without burrowing into the skin or bothering the living tissue, even kill bacteria in some cases. They might be a good candidate for helping to heal wounds or increase natural regeneration or something.