Maybe a plant she nibbled on that produced the white powder. Just thinking whatever the white powder was could be the culprit.
Might be a good idea to put some vitamins into her feed or drinking water.
Bring her inside so you can monitor her eating and drinking and pooping.
I've never seen a...
I am sorry your runner isn't feeling well. Does she still lay? the white powder could she have gotten into something out in the garden that was toxic? we have a list of flushes. Probably would be a good idea to search the area and wherever else she has access to...