We are very lucky (or very careful!) and our girl has never eaten or chewed anything she wasn't supposed to, even when she was a puppy. however, my friend asa Dalmation, and the things she tells me both have me in stitches and fill me with horror!
He once got into the utility room and ate a whole 15KG sack of James Well-beloved, plus the bag.

She said he was laying down groaning with a huge belly. Of course, she immediately rang the vet (her boss) who said to keep a close eye on him, luckily he was OK.
Secondly, she came back from the supermarket and let him out for a wee in the garden while unpacking her shopping, when she went to call him back in, she noticed the postman had left a parcel by the backdoor as she has been out. Her dog had eaten an entire childs potters wheel, including paint, clay and paintbrushes. Again

Luckily, again, he was OK.
That was some a couple of years ago, he is four now, and she is far more vigilant about what she leaves around him, having learnt that he will eat absolutely anything. (she does look after her dog properly, in case anyone is worried, I think she must have just been extremely unlucky!)
So, has anyone elses dog eaten anything so horrifying?