The Thai Ridgeback (Thai: ไทยหลังอาน, RTGS: Thai Lang-An) is a dog from Thailand. The Thai Ridgeback is one of only three breeds that has a ridge of hair that runs along its back in the opposite direction to the rest of the coat. The other two are the Rhodesian Ridgeback and the Phu Quoc Ridgeback. The Thai Ridgeback is a muscular, medium-sized pariah-type dog with a wedge-shaped head, triangular-shaped prick ears, and a very short, smooth coat. It has a pronounced ridge on its back formed by hair growing in the opposite direction that extends from behind the withers to the hips. Puppies are occasionally born ridgeless. Thai Ridgebacks have a muscular and streamlined body, making them extremely agile. The tail is carried upward called a sickle or sword tail. Its forehead wrinkles with enormous expression. Like many eastern breeds, the Thai Ridgeback has retained a 'scissor jaw' where upper and lower teeth interlock when the jaw bones clamp down. The tongue can be black or have black marks. Eyes are almond-shaped and brown but may be amber in blue dogs. The ears are set low and point slightly outward. (Source: Wikipedia.org, CC BY-SA)