Chewed door knobs?

In the vet hospital that I worked at all the door handles bore the marks of another great escape. Curious, I asked the head vet and owner why all the handles were chewed. This is the story she related to me. The vet got here one morning to find a dog loose in the front room and gnawing away at the front door. There were no clips on the door latches of the runs at that time to hold them securely in place. The dog had jumped at the gate in the middle of the night and popped the latch up and open. He then started on the kennel door and chewed the knob of the door until it was no longer smooth and could be turned. He then grasped it with his teeth turned the knob and pulled. When through that door he then picked another and started chewing again. Door by door he made his way out to the front room. I guess he figured he was going to find his master and go home. Then when no master appeared in the front room he worked on the front door. If the head vet hadn't arrived when she did who knows how long it would have taken the dog to figure out the front deadbolt.