I have the SAME problem. I was thinking it was allergies too. She seemed to have more severe reactions at a friends house. She just developed the eye mucus and I thought it could be either because of her hair being in her eyes (so I cut it out) I washed around her eyes last night and this morning she still had mucus in them. She doesnt sneeze much at home...however she has sneezed outside once at home.
LOL...going through all of this stuff would be a ton to read. But hope your yorkie feels better and NOTHING is wrong.
wishing for the best diagnosis but pls let us know what doc says
it may help me. Thanks