Dog

A dog was a quadrupedal mammal native to the planet Earth, related to the wolf. Dogs were domesticated and tamed by humans, who frequently kept them as pets. They came in different breeds of many different shapes and sizes. (TV: Image of the Fendahl, Rise of the Cybermen, Night Terrors, et. al)

The Bandogge was a type of mongrel dog. (TV: The Shakespeare Code)

The Cybus Cybermen converted dogs into two types of Cybernetic servants, Cyberdogs and Cybershades. (COMIC: Enemy Mine; TV: The Next Doctor)

The dog Teazel, who belonged to Edward Lunn, was captured by Zygons in the Lake District in September 1909. The warlord Brelarn used his body-print to assume Teazel's form, as dogs could go where they liked. He was therefore able to spy on the Tenth Doctor, Martha Jones, and others. The real Teazel was eventually rescued from the Zygon ship. (PROSE: Sting of the Zygons)

Dogs were integral to shepherding. In fact, Peri Brown once noticed a herd of sheep running down a dog on the island of Dorsill, which made her think that something was amiss on the island. (PROSE: Grave Matter)

The planet Barcelona reportedly had dogs with no noses, as stated by the Ninth Doctor shortly before he underwent regeneration. (TV: The Parting of the Ways)

On Pete's World, Rose was a small female dog that belonged to Jackie and Pete Tyler. Rose Tyler was annoyed to discover this was her counterpart in that version of the universe. (TV: Rise of the Cybermen)

Wild dogs roamed some places on Earth. They were found on the deserts of Iraq in 1930 and (COMIC: A Wing and a Prayer) on the streets of London during the Year That Never Was. (TV: Last of the Time Lords)

Prisoner Zero took the form of Barney Collins while the real Barney was in a coma. Barney was dreaming about walking his Rottweiler, so Prisoner Zero's "Barney" form had his dog on a leash. As Prisoner Zero was prone to losing track of which of its stolen form's mouths to use, the "dog's" growling and barking came from "Barney's" mouth. (TV: The Eleventh Hour)

In 2011, Jim Purcell owned a dog named Bernard, who watched as his owner was absorbed by the carpet into the doll's house. (TV: Night Terrors)

The Eleventh Doctor played with a toy robot dog named Yappy while briefly working as a sales assistant in Sanderson & Grainger in Colchester in 2011. (TV: Closing Time)

During the 22nd century Dalek invasion, packs of dogs were mentioned as roaming the woods and were said to hunt travellers. (TV: The Dalek Invasion of Earth)

On Gemino, the First Doctor, John and Gillian discovered a dog in the ruins of Gemino City. They followed it back to its master, one of the survivors of the war between Gemino and Gemina. (COMIC: The Secret of Gemino)

The form of the robot K9 was based on that of a dog. (TV: The Invisible Enemy)

A guard dog was the victim of the Master's TCE. (TV: The Mark of the Rani)

Dogs were used in police searches to sniff out missing people. Gordon Galloway used police dogs in his search of Swallow Woods. (PROSE: The Way Through the Woods)

A unique breed of dog existed on Trenzalore that was seven feet long and five feet tall, with double thick coats that enabled them to withstand anything from the planet's typical frigid temperatures to its worst winters. (PROSE: Strangers in the Outland)

Behind the scenes

 * During the filming of The Ribos Operation, Tom Baker was bitten by Paul Seed's Jack Russell terrier when he tried to have it perform a trick Seed himself had done. This left Baker with a deep cut to his upper lip. As a result, publicity stills for The Ribos Operation saw him wearing a sticking plaster on his face, and for the remainder of filming Tom Baker required a heavy and uncomfortable makeup application to cover the wound. To lessen the necessary makeup coverage and explain the healing wound on-screen, a scene was added to the beginning of the following story (The Pirate Planet) wherein the Doctor struck his lip on the TARDIS console. The scar remained visible for much of Season 16. (DCOM: The Pirate Planet)