Molly's always been dreadful about tearing toys to bits, so that I started only letting her have them when I was playing with her. A few months ago I bought a £1 plastic squeaky ring-doughnut and after one game forgot to put it away. She didn't chew it up so it got left out and is still in one piece. Just her growing up I hear you thinking. As did I so bought another cheap plastic toy, bone-shaped and after we'd played let her keep it. Well it was shredded within minutes. Still not conclusive? I sometimes buy bone-shaped rawhide chews which Molly gnaws and eventually eats. A couple of weeks ago I bought a ring-shaped rawhide chew. Well it hasn't been chewed at all - played with but not chewed. So - Molly believes that hoop-shaped things must not be chewed.
This evening she's finally chewed up and swallowed that same rawhide ring ( she hasn't had any other rawhide since I bought it) - best value chewable I've ever bought! I think she was feeling desperate as I'm trying to get some weight off and had cut down her dinner. The plastic doughnut ring is still in one piece.