20. Tibetan Mastiff

The Tibetan Mastiff are huge in size and very loyal. They also have double coats so there good winter dogs. There also great guard dogs. These dogs also are not willing to be obedient so it might take some work to train them.

19. Swedish Vallhund

The Swedish Vallhund are very athletic dogs. They were traditionally used as herding dogs. This breed comes in a variety of colors. Also they can have different tail lengths from a bobtail to a full curly tail.

18. Bedlington Terrier

The Bedlington Terrier is very similar to a lamb. This breed is very athletic even despite is appearance. This breed is traditionally used for racing or catching vermin. Its a graceful dog that builds up endurance.

17. Finnish Spitz

The Finnish Spitz can resemble a fox in many ways. The Finnish Spitz features erect ears, a dense coat, and a bushy tail. It also comes in arrange of colors from pale honey to deep auburn. The breed is known for its intelligent expression and brisk movement.

16. Otterhound

As its name implies, the massive Otterhound is very capable in the water. The scent hound has wedded feet and a rough, double coat, which also makes it a greater hunter on land. Otterhound’s excel as pets too, being inquisitive, boisterous, and amiable.

15. Norwegian Lundehund

With six toes on each foot, prick ears that it can control at will, and the ability to tip its head backward to touch the backbone. The Norwegian Lundehund is unlike any other breed. Its unique build helped it excel at Puffin hunting, but it also makes an “easy to live with” pet.

14. Chinook

The name Chinook means “warm winter winds” in Inuit , and its double coat keeps it comfortable in the cold. The Chinook originated in New Hampshire as a drafting and sled-dog racing breed combining the power of a freighting dog and the speed of lighter racing sled dogs.

13.  Catahoula Leopard Dog

The often multi-colored or spotted Catahoula  Leopard Dog is believed to be the first dog breed in the United States. It was named after Catahoula Parish in Louisiana and was traditionally used to hunt wild boar.

12. Peruvain Inca Orchid

The Peruvain Inca Orchid has been around since before AD 750, and today it remains an uncommon but treasured pet. The “agile, smart and swift” breed is good at hunting and lure coursing as well. But its most notable quality  is that is sometimes hairless, with skin that appears  in a variety of colors.

11. Thai Ridgeback

The Thai Ridgeback was previously unknown outside of its country of origin, but it is now gaining popularity elsewhere. What makes it most unique? A ridge of hair, growing in the opposite direction of its coat, running along its back. Only two other breeds have the same feature.

10. Azawakh

This West African sighthound makes a fiercely protective companion and guardian, and an extremely intelligent lure courser. The breed is elegantly built and features a short coat in a wide variety of colors and markings.

9. Lagotto Romagnolo

Hailing from the Romagna sub-region of Italy, the Lagotto Romagnolo was named as a lake dog and traditionally used as a gun dog. Its most interesting occupation, though, is truffle hunting.

8. Mudi

This Hungarian herding dog is as active as it is versatile. It makes a talented hunter, rodent exterminator, herding dog and flock guardian, but as a pet the Mudi is the happiest when given long walks or jogs and a large area in which to run free.

7. Stabyhoun

The Stabyhoun comes from Friesland, a province in the Netherlands, and today there may be fewer than 4,000 in existence. Stabyhoun’s make excellent hunting and guard dogs, and they’re also great at catching vermin like moles and rats.

6. Karelian Bear Dog

The Finnish Karelian Bear Dog is one of the top 10 most common breeds in its home country. Originally used for hunting and as a watchdog, it has quick reflexes and a fearless nature, and is still popular with big-game hunters.

5. Carolina Dog

Also known as the American Dingo, the Carolina Dog actually started out as a wild and  free roaming dog. It was discovered in the cypress swamps of the Southeastern United States around the 1970s, and is now bred in captivity.

4. New Guinea Singing Dog

The New Guinea Singing Dog get its name from its unique vocalization, but the once-wild breed get its reputation as an excellent companion from its intelligence and physical ability.

3. Catalburn

Possibly because of severe inbreeding due to their rarity, the Catalburn is one of the only  dogs in the world featuring a split nose and suspended ears. They were originally bred for hunting in Turkey.

2. Fila Brasileiro

The Fila Brasileiro is believed to have origins in a number of  breeds like the Mastiff and Bloodhound, which could explain its large bones, loose skin and smooth coat. The working breed is known for its tracking ability, but also for its sometimes aggressive temper.

1. Telomian

The Telomian is the only known Malaysian breed to live elsewhere, but originally it was bred by the Orang Asli indigenous people to catch vermin. Because the Orang Asli built homes on stilts to stay safe from dangerous animals, Telomian’s developed an unusual climbing ability.

Reference: http://www.outsideonline.com/outdoor-adventure/dogs/20-of-the-Worlds-Rarest-Dog-Breeds.html#slide-21