Yesterday we stood talking to the crossing guard when Oreo found a metal stick wrapped in green plastic. It was about an inch in circumference. The stick as was the kind local realtor's use to post their signs on corners. Oreo put it in his paws and started chewing on it.
The crossing guard asked if I should take it away from him. I said, "No, he cannot hurt it and he's busy, so it's fine."
A few minutes later she looked at him and said, "Did he chew through the metal?"
Sure enough, the stick was broken in two. He managed to gnaw through the metal without breaking the plastic.
We stood there staring at the dog, who was still happily playing with the broken stick. The crossing guard kept saying, "I cannot believe he did that." The girls just laughed like it was something he did all the time.
I couldn't either at first, but given some of the other things I've seen him do, I guess I'm not surprised that he's strong enough to chew through metal. It does make me want to be extra careful when I'm playing with him. An accidental chomp could be really painful.