We got Blue from a listing on Craigslist around Easter.  He was 6 months old at the time.  His two favorite things to eat then were toilet paper/tissues and socks.  We thought he was just carrying and or chewing the socks until we saw him barfing in the back yard.  It took a few seconds to recognize the article.  It was a sock.  We tried to keep socks picked up which isn't easy with two young kids and a husband.  I awoke at least a few nights hearing him barfing only to find another sock on the floor or on his bed.  It reminded me of a cat barfing up a hair ball, but with Blue it was a sock.  He has since learned from his experience that he cannot digest nor pass socks.   I still catch him occasionally with a tissue in his mouth but he is a good dog and will "drop it".  I expected a puppy to chew things like shoes, furniture and even toys this time around, but not socks.  Blue is a Boxer Siberian Husky mix and the BEST dog.