The longest ears on a dog measured 34.9 cm (13.75 in) and 34.2 cm (13.5 in) for the right and left ears, respectively, on 29 September 2004. They belong to Tigger, a bloodhound, who is owned by Bryan and Christina Flessner of St Joseph, Illinois, USA.
Tigger has won many show titles and over 180 Best of Breed awards. He was inducted into the Bloodhound 'Hall of Fame' in 2003.
Unfortunately Tigger passed away in October 2009.

Source: http://www.guinnessworldrecords.com/world-records/longest-ears-on-a-dog-ever