No way on the previous save, but are you sure you lost it.
Items needed for quests, cannot be sold, no can a pet eat them..you may have dropped it, but I think the word "quest item" would grab your attention.
I found some items were placed not in inventory screen, but in the log book..can't remember all the tabs..but do go in and check there first.
I know a headress and a few other things for quest needs were there for me..
Let us know..and btw: what was it?