Beorn, who Bilbo met in 'The Hobbit,' had several animals and some of them were dogs.

He had numerous of these grey hounds, and they were all able to walk on their hind legs and and carry objects with their front legs. When Bilbo and Company were living with Beorn, the dogs seemed to understand what Beorn said to them and helped set the table for dinner.
Encyclopedia entry originally written by ABagginsOfTheShire