Some of them used to be hot dogs, but the breeds and mixes that make our 20 Dogs on the Decline list have fallen in popularity over the past decade. To determine which breeds have experienced the steepest decline, we looked at Vetstreet's data and compared their popularity in 2002 to their rank in 2012. Here are the results, and a few are sure to surprise you.

No. 1: Greyhound

No. 1: Greyhound

No. 48 most popular breed in 2002, No. 117 in 2012

The Greyhound is known for being gentle and affectionate, but even those appealing attributes couldn’t keep this dog from declining in popularity over the past decade.

No. 2: Smooth Fox Terrier

No. 2: Smooth Fox Terrier

No. 103 in 2002, No. 153 in 2012

The Smooth Fox Terrier is not necessarily the right dog for all homes. He’s outgoing and active and wants to dig, bark and investigate all the time. This makes him perfect for activities like hunting and earth dog trials but a bit problematic for calm and quiet families.

No. 3: Spitz Unknown/Mix

No. 3: Spitz Unknown/Mix

No. 109 in 2002, No. 159 in 2012

Spitz breeds were developed to bark, and bark they do, often in a variety of sounds. This active mixed breed needs daily exercise that mentally and physically challenges him. Otherwise he’s prone to destructive and noisy behavior.

No. 4: Schipperke

No. 4: Schipperke

No. 94 in 2002, No. 141 in 2012

With a nickname like “little black devil,” it may be no surprise that the Schipperke has fallen somewhat out of favor. The highly energetic and highly intelligent breed is a great sports competitor and watchdog, but his take-charge attitude means that he’s liable to walk all over an owner who isn’t prepared to stand up to his antics.

No. 5: Chow Chow

No. 5: Chow Chow

No. 26 in 2002, No. 66 in 2012

This excellent guard and watchdog is a Chinese breed developed as an all-purpose dog for hunting, herding, pulling a cart and guarding the home. Chow Chows have a reputation for being aggressive toward people, but with early and frequent socialization, they can make excellent family pets.

No. 6: Dalmatian

No. 6: Dalmatian

No. 54 in 2002, No. 87 in 2012

The Dalmatian has long been a favorite firehouse dog, and we can only imagine the pooch’s popularity rose with the mid-’90s release of 101 Dalmatians. Since what goes up must come down, that may explain why this breed has steadily declined in recent years.

No. 7 (tie): Samoyed

No. 7 (tie): Samoyed

No. 104 in 2002, No. 135 in 2012

Originally a reindeer herder, the “Smiling Sammie” can be a tad stubborn, but the Samoyed is also a loving and gentle family member.

No. 7 (tie): Keeshond

No. 7 (tie): Keeshond

No. 104 in 2002, No. 135 in 2012

The Keeshond is a happy-go-lucky Spitz breed that requires less exercise than you might expect, but the “Velcro” dog loves attention, and lots of it, which could be a little too much for some busy families.

No. 9: English Cocker Spaniel

No. 9: English Cocker Spaniel

No. 83 in 2002, No. 113 in 2012

This larger relative to the Cocker Spaniel was first recognized as its own breed in 1946 when the two breeds diverged greatly in appearance. The English Cocker Spaniel diverges further, with some that are “field bred” and some that are bred to show.

No. 10: Silky Terrier

No. 10: Silky Terrier

No. 74 in 2002, No. 103 in 2012

The tiny Silky Terrier doesn’t acknowledge his small stature, so those hoping to bring home a lap dog will be sorely disappointed. He wants to play, dig, run and be a charming little watchdog.

No. 11: Basenji

No. 11: Basenji

No. 91 in 2002, No. 119 in 2012

The Basenji is often described as catlike, and although he’s highly curious and intelligent, he’s not the right dog for anyone who holds possessions dear and doesn’t have a rather hefty sense of humor. He’s mischievous and has a mind of his own, so if you want to stay a step ahead of him, you'll need to keep on your toes.

No. 12 (tie): Cairn Terrier

No. 12 (tie): Cairn Terrier

No. 53 in 2002, No. 80 in 2012

Small but active, the Cairn Terrier loves to play. He’s intelligent but independent (or, as many would say, stubborn), so you’ll have to be prepared to stick to your guns when training him. He’s not a good choice for families with other small, furry animals, as the Cairn was bred to root out otters and other vermin, and that instinct is still strong.

No. 12 (tie): American Eskimo Dog

No. 12 (tie): American Eskimo Dog

No. 50 in 2002, No. 77 in 2012

The American Eskimo Dog comes in three sizes but just one level of intelligence — super smart. He’s healthy and affectionate but barks, sheds and isn’t always a good choice for homes with young children.

No. 14 (tie): Lhasa Apso

No. 14 (tie): Lhasa Apso

No. 34 in 2002, No. 60 in 2012

Dignified and mischievous, the Lhasa Apso is an excellent watchdog due to his alert and suspicious nature. His signature long, flowing coat is certainly eye-catching, but it requires extensive grooming.

No. 14 (tie): Toy Fox Terrier

No. 14 (tie): Toy Fox Terrier

No. 108 in 2002, No. 134 in 2012

This American-bred toy dog was created to keep rats and other small vermin off farms. He’s playful, silly, fearless and makes a wonderful watchdog, but the Toy Fox Terrier is a terrier in the truest sense, so if bored and left to his own devices, he can become destructive.

No. 14 (tie): Norwegian Elkhound

No. 14 (tie): Norwegian Elkhound

No. 118 in 2002, No. 144 in 2012

Originating in Norway as a watchdog, flock guardian and big-game hunter, the Norwegian Elkhound has a thick, gray coat and a tail that curls tightly over his back. He’s bold and boisterous and needs plenty of exercise to challenge him physically and mentally. Otherwise he can become noisy and destructive.

No. 17 (tie): Italian Greyhound

No. 17 (tie): Italian Greyhound

No. 64 in 2002, No. 89 in 2012

Although the Italian Greyhound is essentially a Greyhound in miniature, he has no understanding of his small size and has been known to hurt himself by leaping off furniture. Another thing he doesn’t always understand? The need for housetraining.

No. 17 (tie): Scottish Terrier

No. 17 (tie): Scottish Terrier

No. 65 in 2002, No. 90 in 2012

He’s lively and intelligent, but the Scottish Terrier can also be quite serious and scrappy with other dogs. He’s affectionate to those he likes but may take awhile to warm up to strangers, and, as a terrier, he’ll hunt little critters that cross his path.

No. 17 (tie): English Setter

No. 17 (tie): English Setter

No. 73 in 2002, No. 98 in 2012

The English Setter is known for his distinctive feathered coat and gentle nature. He’s the smallest of the three Setter breeds, and if given enough exercise, he can be a mellow and friendly family pet.

No. 17 (tie): Wire Fox Terrier

No. 17 (tie): Wire Fox Terrier

No. 101 in 2002, No. 126 in 2012

Interestingly enough, although the Wire Fox Terrier earned a spot on this list of breeds on the decline, 2012 was the year a breed repeated as Best in Show at the National Dog Show, and it was the Wire Fox Terrier who took home the trophy. We wonder if we’ll see this spunky dog back on the list of hottest breeds and mixes next year.