When AvatarAang reconstructed the the zoo outside the city walls, he used his bison whistle to call for the zoo animals but accidentally also called in multiple domesticated creatures, among them a dog, which ended up in an elephant mandrill's pen.
The canine that was present at the oasis had black fur with a brown underbelly. It had a light brown muzzle and white paws, and the end of its tail was a beige color.
Another breed of dog in Ba Sing Se was brown-furred. It had tiny paws and long floppy ears that fell down the sides of its head. Its face contained light brown features and golden-colored, droopy eyes.
The dog which inhabited the Misty Palms Oasis is similar to a Bernese Mountain dog, though it is thinner and has less hair. It also bears a resemblance to the Appenzeller Sennenhund.