We have one, no i wouldn't leave it in there. Just my personal opinion. I usually stay home all day. Unless for a few errands, so she's not in a crate very long. But i am too scared to leave ANYTHING in there for fear of an accident happening.
Someone else might offer more help, but I don't leave them in with Tuck unless i can watch her with it.
P.S. Pi is absoultely beautiful and i loveeeeeeeeeee your siggy!!!!!!!!!!!!!!
I do have blue one, and No, I won't leave those in crate unsupervised with ZsaZsa(4months)
Blue rubber is pretty soft, so I am afraid that she may be able to tear it and swallow pieces.
I only leave Nylabones with her in the crate.