Smilla,

I wish I'd seen this post earlier. My Buddy was the same way.
Walked with nose to the ground all the time & was so fast at
grabbing things & swallowing even before I could react.

I think I also would be concerned since it was plastic. Is your
Vet's office open on weekends? I think I'd call them & see if they
have any advice other than to wait & see if it passes. Maybe
they could tell you some warning signs to lookout for should
the object not pass out in a bm.