My first thought was that you didn't get him as a tiny puppy. Don't know what his background is but mine are rescues and they have odd reactions to things that I would never have expected.
__________________ Joanne  Eli  Chipper Eva  Snowboy Rosie(R.I.P. 1996-July 29, 2013) Cocoa(R.I.P 1998-April 26, 2012): |