Aziza
3
Companions (Thralls and Pets alike) have a mechanik that they need to eat.
They will take the last eaten type of food from the boxes and pots respectively. If you do not have this specific food stored there, the companions will plunder everything else, even stuff they cannot eat, resulting in this mess.
(I found out about that when I investigated the “Gazelle takes meat”-Problem. Its probably most common with it because no one usually throws plant fiber (what you usually put in the inventory i assume) into their feeding box)