Interesting thought Bob.. Definitely could have happened.. I had changed my linen and did a cursory spray of a 'febreze' about 5hr earlier... My girl is renowned for rooting under the covers and playing 'cover monster' with my other dog (basically she is under the covers biting his feet) so it is possible that she got residual on her face and reactivated it... Considering the chances spider lurked in the snow or she stick her nose in an active cat hole that had a slider suddenly in the area, it is the most plausible..
I agree with Sarah that diagnostic learning can occur online.. I do agree as well that vets can be totally oblivious to what is going on and are really on preview to their experiences in their practice... Online has the world, and while I wouldn't suggest using online as a sole source of knowledge or expertise, I do certainly utilize its capabilities.. No further reactions have occurred and I half dosed her in the morning as a final precaution... She ran 24hr urban trail in 0°F yesterday, and outside of one area for a moment where she seemed to lose focus, something she never does, she did a brilliant job.. Thanks again everyone