Gotta keep your pets happy. Usually regular commands are enough to do that for horses and packies etc. I've haven't lost a pet in years because when I log in I hop off and say "all follow me", if I spend a while doing something I hop off after a bit and do the same, and I do this before I log out.
Now, I think when a pet goes wild it will drop the contents of it's backpack to it's feet and this will be in an un-pickupable backpack, but you can open it and grab the stuff. This beetle might be bugged, she might want to kill it just in case (to see if the stuff is hiding) then get a new one.