During a 1983 family vacation, Mitt Romney transported his family's pet dog, Seamus, on the roof of an automobile for 12 hours. This incident became a subject of media attention for Romney in both the 2008 presidential election and the 2012 presidential election.

In June 1983, Romney and his family were preparing for their annual vacation from their Belmont, Massachusetts home to a family cottage in Beach O'Pines, Ontario. Seamus was enclosed in a carrier that Romney had equipped with a windshield and strapped on the roof of the family's Chevrolet Caprice station wagon. Sometime during the 650-mile trip from Massachusetts to Ontario, the dog became afflicted with diarrhea, causing excrement to flow down the windows of the car. Romney stopped at a gas station to wash Seamus, the carrier and the car, then put Seamus back in his carrier, and continued the 12-hour trip to the family's vacation home.

Seamus ( /ˈʃeɪməs/ SHAY-muss), an Irish setter, was an active, outgoing dog, and was the Romney family's first pet dog. A few years after his ride to Canada, Seamus was given to Mitt Romney's sister, Jane Romney Robinson of California, who said, "He kept ending up at the pound. They were worried about him getting hit crossing the street. We had more space, so he could roam more freely." Seamus passed away in the early 1990s.

Séamus Irish pronunciation: [ˈʃeɪməs], is a male first name of Celtic origin. It is the Gaelic equivalent of the name James. The name James is the English New Testament variant for the Hebrew name Jacob. It entered the Irish and Scottish Gaelic languages from the French variation of the late Latin name for Jacob, Iacomus; a dialect variant of Iacobus, from the New Testament Greek Ἰάκωβος (Iákōbos), and ultimately from Hebrew word יעקב (Yaʻaqov), i.e. Jacob. Its meaning in Hebrew is "one who supplants" or more literally "one who grabs at the heel". When the Hebrew patriarch Jacob was born, he was grasping his twin brother Esau's heel.

Variant spellings include Séamas, Seumus, Shaymus, Sheamus and Shamus. Diminutives include Séimí, Séimín and Séamaisín. In the United States, the name "Shamus" is sometimes used as a slang word for private detective.

The domestic dog (Canis lupus familiaris), is a subspecies of the gray wolf (Canis lupus), a member of the Canidae family of the mammilian order Carnivora. The term "domestic dog" is generally used for both domesticated and feral varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in human history. The word "dog" may also mean the male of a canine species, as opposed to the word "bitch" for the female of the species.

The present lineage of dogs was domesticated from gray wolves about 15,000 years ago. Remains of domesticated dogs have been found in Siberia and Belgium from about 33,000 years ago. None of these early domestication lineages seem to have survived the Last Glacial Maximum. Although mDNA suggest a split between dogs and wolves around 100,000 years ago no specimens predate 33,000 years ago that are clearly morphologically domesticated dog.

Dogs' value to early human hunter-gatherers led to them quickly becoming ubiquitous across world cultures. Dogs perform many roles for people, such as hunting, herding, pulling loads, protection, assisting police and military, companionship, and, more recently, aiding handicapped individuals. This impact on human society has given them the nickname "Man's Best Friend" in the Western world. In some cultures, dogs are also source of meat. In 2001, there were estimated to be 400 million dogs in the world.