He also had a pair of bald eagles and a Newfoundland dog. It affects larger breeds such as the Newfoundland Dog and the Golden Retriever. The Newfoundland dog is a large working dog. Lord Byron had a Newfoundland dog named Boatswain. Sir Edwin Henry Landseer depicting a Newfoundland dog. Many St. Bernard Dogs have Newfoundland Dog in their ancestry. The Landseer Newfoundland dog is known for its sweet disposition, gentleness, and serenity. Byron had a great love of animals, most notably for a Newfoundland dog named Boatswain. The Newfoundland dog is known for its calm and docile nature and its strength. Byron had a beloved Newfoundland dog named Boatswain, who died of rabies in 1808.