Dogs come in an astounding variety of sizes, from mastiffs the size of miniature horses to teensy teacup-sized companion dogs. We've looked at the world's largest dog breeds, and now it's time to explore some of the smallest. Here are 12 diminutive dog breeds.

Chihuahua

Chihuahua running through a fieldChihuahuas are popular dogs as pets. (Photo: alexks/Shutterstock)

There is only one breed of Chihuahua, but the variation within the breed is amazing. These tiny dogs have long coats, smooth coats, a diversity of coat colors, and even two distinct head shapes (an apple-shaped head or a deer-shaped head. Seriously). They weigh a feather-light 4-6 pounds, and stand only 6-10 inches tall.

Chihuahuas are low-maintenance dogs when it comes to grooming, but they can be high-maintenance when it comes to training. They usually become devoted to a single person and become protective, which can make living in a house with children a challenge. This isn't to say Chihuahuas can't make great family dogs, but the personality of the dog and the patience and training by the family are important factors.

If you're looking for the very, very smallest of the dog breeds, this is it. The Chihuahua is recognized as the tiniest of them all. However, there are so many more tiny dog breeds out there with their own amazing traits, so keep scrolling.

Chihuahuas wearing a bow tieChihuahuas are famous for their huge eyes, and of course their modeling skills. (Photo: Cressida studio/Shutterstock)

Brussels griffon

The Brussels griffon wearing a sweaterThe Brussels griffon has an adorably Ewok-like look. (Photo: Okssi/Shutterstock)

This uncommon breed was created in Brussels, Belgium, hence its name of the Brussels griffon. This long-legged, short-faced dog was originally bred as a terrier kept in stables to hunt rodents. However, today they are eye-catching pets.

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Brussels griffon dogs typically stand around 7-8 inches tall and weigh 7-12 pounds. There are two coat types, rough or smooth, and a few different coat colors.

This breed tends to bond with one human and does not enjoy being around children. However, they do usually get along well with other animals in the house, and so can make a great pet in a home with other pets. While they love to snuggle, they also love to play and roughhouse. They're smart, but can be sensitive and also have a stubborn streak as many terrier breeds do, so they need a patient trainer.

Three Brussels griffon dogs with rough or smooth coats Brussels griffon dogs have rough or smooth coats and a variety of coat colors. (Photo: otsphoto/Shutterstock)

Pomeranian

Pomeranian playing in leavesThe Pomeranian is a joyful ball of fluffy fur. (Photo: Rita Kochmarjova/Shutterstock)

This spunky little fuzz ball is a spitz type breed, and definitely a popular pet. They stand between 5-11 inches tall and weigh a mere 4-8 pounds. In other words, if some "pom poms" look large, it's all fur and personality that's filling them out.

In fact, that fur is one of their defining characteristics. Pomeranians have the most coat colors of any breed of dog, with 18 colors, ranging from the common tan to white, black and everything in between. They have combinations of colors and can even be spotted or brindle. Their thick coat is actually a double coat, with a soft, thick, short undercoat and long, straight, harshly textured outercoat. Grooming is a necessity for these dogs, including a trim every couple months. Also, if you're considering a Pomeranian as a pet, be forewarned that the undercoat sheds twice a year.

Despite all the need for grooming, their alert, extroverted personality makes them worth the work. They're smart little dogs, and can be easily trained. An owner definitely needs to implement training, too, because Poms can be territorial and develop habits of excessive barking or aggressiveness with other dogs. An owner who can work with the assertive, confident nature of these loving dogs will find a fast friend.

Affenpinscher

Affenpinscher The Affenpinscher is from Germany, and its name means "monkey-like terrier." (Photo: Joakim Lloyd Raboff/Shutterstock)

If the Brussels griffon was a new breed for you, we're guessing you haven't heard of this one either. The affenpinscher has a similar look to the Brussels griffon, and originated in Germany to fulfill the same role of rodent control in kitchens and stables. The breed's name translates to "monkey-like terrier" which is whimsical, but the French describe it as the "diablotin moustachu" or mustached little devil. Either way, you know that this breed is full of personality and feistiness.

The affenpinscher stands between 9-12 inches tall and weighs around 7-13 pounds. But don't let the tiny size fool you. These dogs are active indoors and love daily walks. They're curious and playful, but also are stubborn and protective. Because they have a tough-guy personality, they need training and respond best to positive reinforcement methods, such as clicker training. They are fearless and a bit territorial, so they don't do well in homes with children. But when paired with the right owner, these scruffy little dogs make for a smart, sassy best friend.

Papillon

Papillon running in grassThe papillon is a party in a tiny package. (Photo: Mikkel Bigandt/Shutterstock)

If you're all about the ears, the papillon is probably the dog for you. The name is perfect for this breed, as it means "butterfly eared." Normally the ears are upright, but some papillons have dropped ears. These dogs have a corresponding name of phalène, which is French for "moth."

Papillons stand 8-12 inches tall and weigh 7-10 pounds. You've been hearing about breeds that have trouble around children and strangers; the papillon stands in contrast. This breed is friendly and self-assured, and when properly socialized, does well with children, strangers and other pets. They are well known to be great companion animals, even if they can be a bit on the vocal side.

Papillons are very energetic and intelligent, and so do great with owners who want to engage their speed and smarts. Agility and rally obedience are perfect pastimes for papillons and their handlers.

And don't forget: EARS!

Papillon glamour shotThe breed's coat is luxurious and perfect for glamour shots. (Photo: Jagodka/Shutterstock)

Yorkshire terrier

Yorkshire terrier standing on grassYorkshire terriers are always a popular pet, though they require quite a bit of grooming. (Photo: Viorel Sima/Shutterstock)

The Yorkshire terrier is a familiar breed. They started out as ratters in Yorkshire, England, but have grown to become a much-loved companion animal. In fact, according to the American Kennel Club, it is the sixth most popular breed of dog and is the most popular toy breed.

Yorkies stand 6-9 inches tall, and should be under 7 pounds, though some Yorkies may grow to be a bit larger. They are also known for their long, luxurious coats, which are considered hypoallergenic as they shed less than other dogs. But of course, grooming is still necessary for these long-haired dogs.

Yorkies are a well-rounded dog, and love to be engaged in training. But they aren't particularly high-energy dogs. They're perfect for someone who likes to take a long walk or two every day, then cuddle on the couch. Like so many toy breeds with terrier backgrounds, they aren't particularly fond of children, other dogs or strangers, and can be vocal. But with the right amount of socialization and training, they can be a friendly, balanced dog.

Russian toy

Russian toy dog sleeping in grassThis breed was developed in Russia and was popular among the aristocracy. (Photo: otsphoto/Shutterstock)

If you haven't heard of this breed before, we wouldn't be surprised. This dreamy little dog was almost entirely unknown outside of Russia, its country of origin, until the 1990s. The Russian toy is similar in size to the Chihuahua, standing between 7-11 inches tall and weighing 2-6 pounds. It is also similar to Chihuahuas in that the breed has two varieties of coat, a smooth coat and a long coat. And you may be reminded of the papillon in its big ears with feathered fur lining the edges.

The Russian toy was bred to be a ratter and watchdog, and thus can be quite vocal. They are loyal, playful family members, including with kids, and benefit from an active household who treats this breed like a dog and not a, well, toy. Walks are preferred to being carried around. They're also bright dogs who enjoy training ... or a good book!

Russian toy dog standing on open bookRussian toy dogs are intelligent as well as adorable. (Photo: dien/Shutterstock)

Toy fox terrier

Two fox terriers standing on a deskThis breed is full of energy and confidence. (Photo: Rosa Jay/Shutterstock)

A descendant of the smooth fox terrier, the toy fox terrier has become its own breed, recognized by the AKC as recently as 2003. These perky dogs stand 8.5-11 inches tall and weigh anywhere from 3.5-9 pounds.

This tiny dog is like a little powder keg, with plenty of energetic activity stored in their little frames. Fast, agile, courageous and smart, the toy fox terrier is great for someone who wants an active, trainable dog small enough for apartment living. Great for anything from agility to hiking (on leash, considering they're a terrier with a very high prey drive), the toy fox terrier loves to play, explore and learn. They stay active well into their older years.

Japanese Chin

Japanese chin dogThe Japanese chin has a long coat and distinctive face. (Photo: dien/Shutterstock)

This very old breed of dog has been around for more than a thousand years. It has a long history of being a companion dog and it shows in its friendly, happy nature. It is a perfect lapdog with a height of 8-11 inches and a weight of 3-15 pounds.

If you consider yourself a dog person but still quite like cats, then this is probably the breed for you. It is considered cat-like in disposition, with a bit of an independent streak, a propensity for jumping high onto furniture to have a good view of the room, and even a tendency to use its paws to wash its face.

The Japanese Chin is a loving dog with family, and a little reserved with strangers but still friendly. They are known to shape their personality around their owners — being a mellow dog with a quiet owner, and a playful dog with an active owner. The Japanese Chin also loves to learn interesting new tricks and thrives on variety in training. Overall, the breed is a comical, well-rounded companion.

Chinese crested

Three Chinese crested dogsYou'll never have your Chinese crested dog mistaken for another breed! (Photo: Medvedev Andrey/Shutterstock)

This small dog breed might be one of the most recognizable of them all. The Chinese crested stands about 11-12 inches high and weighs 10-13 pounds. And, you probably noticed it is mostly naked. Many individuals of the breed are hairless except for a crest of fur on their heads, "socks" on their feet, and a plume of fur on their tails. However, there is a recessive gene in some dogs that cause them to have (gasp!) a full coat of fur. These are known as "powder puffs."

Though they are athletic, the Chinese crested is a low-energy breed, happy to spend the day curled up in bed next to you as you read the paper. They're what's called a "Velcro dog" in that they become intensely bonded to an owner, dismissing strangers and sticking with their human as much as possible. They are social, but needy dogs. Needy of both love and, often, a sweater. That said, you'll probably never ceased to be entertained by the looks and antics of this little breed.

Chinese crested dog running in field of dandelionsThis fun-loving breed doesn't mind letting its freak flag fly! (Photo: DragoNika/Shutterstock)

Miniature pinscher

Miniature pinscher runningMiniature pinschers look like tiny versions of Doberman pinschers. (Photo: Mikkel Bigandt/Shutterstock)

Love the look of a Doberman but need a dog that fits in a small apartment? Voila! Meet the min pin. This is quite an old breed, originating in Germany, and wasn't created to be a mini version of anything. It just happened to be named as if it were when it was introduced to the U.S. The breed stems from a mix of dachshund, Italian greyhound and goodness knows what else over its long history.

These small dogs stand 10-12 inches tall and weigh 8-10 pounds. They have a sturdy build that suits their assertive, outgoing personality. Athletic and energetic, these are great dogs for active adults. And also for adults that like to play hide-and-go-seek (mostly-seek), as this breed is known to be a great escape artist. When not escaping, they love to be the watchdog and alert owners to any possible intruder.

Min-pin standing in a field of flowersThe min-pin breed has a short, smooth coat. (Photo: DragoNika/Shutterstock)

English toy spaniel

Two English toy spanielsThe English toy spaniel is a more reserved companion. (Photo: Erik Lam /Shutterstock)

The English toy spaniel is also known as the King Charles spaniel, but is not to be confused with the Cavalier King Charles spaniel. In fact, the two breeds have an interesting history. The English toy spaniel went from having a more pointed snout to a flatter snout as the breed was mixed with others such as the Japanese Chin and pug. In the late 19th century, an American named Roswell Eldridge offered a monetary prize for a breeder who could bring back the more pointed muzzle. The result was the Cavalier King Charles spaniel. But of course, the much-loved English toy breed didn't disappear, and is smaller than its newer peer, reaching a height of 10-11 inches and a weight of 8-14 pounds.

These long-haired beauties are mellow, good-natured dogs. Playful but gentle and highly loving, this breed becomes utterly devoted to an owner, often to the point of having issues with separation anxiety. They are fairly low energy, and are happiest cuddling on the couch with their human BFF.

Jaymi Heimbuch ( @jaymiheimbuch ) focuses on wildlife conservation and animal news from her home base in San Francisco.