My puppy ate plastic and chews alone. How to prepare for long periods?

Thanks for using Petco Pet Education Center, formerly Petcoach! That looks like a relatively small amount of plastic and it looks like she nibbled at it bit by bit. So unless a large chunk is missing or she is a tiny breed puppy (like less than 5 lbs), I am not very concerned. You may find tiny pieces in her stool within 48 hours of eating it in most cases. Sometimes you see nothing because the bits were too small.

The boredom and chewing though, you will have to address. Obviously, next time you leave be sure there is NOTHING within her reach except a metal or ceramic water bowl and approved chew toys.

One idea is a toy like a Kong. Smear some peanut butter in the little opening and put the whole thing in the freezer for an hour (or overnight the night before). This will buy a solid hour or more for many puppies.

Another idea is -depending on her size and the feasibility - switch her to a crate. Crates work wonders for many dogs- puppies especially, there is nothing for her to destroy, etc.

Best of luck to you and your girl!