
Terrier is a type of dog originally bred to hunt vermin. A terrier is a dog of any one of many breeds or landraces of the terrier type, which are typically small, wiry, game, and fearless. Terrier breeds vary greatly in size from just 1 kg (2 lb) to over 32 kg and are usually categorized by size or function. There are five different groups of Terrier, with each group having different shapes and sizes.

The Airedale Terrier, also called Bingley Terrier and Waterside Terrier, is a dog breed of the terrier type that originated in the valley (dale) of the River Aire, in the West Riding of Yorkshire, England. It is traditionally called the "King of Terriers" because it is the largest of the terrier breeds. The Airedale was bred from the Old English Black and Tan Terrier, the Otterhound and probably some other Terrier breeds, and has contributed to other dog breeds, such as the Yorkshire Terrier. Originally bred to serve as a versatile hunting and all around working farm dog, in Britain this breed has also been used as a war dog, guide dog and police dog. In the United States, this breed has been used to hunt big game, upland birds, and water fowl, and serve in many other working capacities.

The American Hairless Terrier is a breed of feist from the United States that was derived from the Rat Terrier. The breed descends from a single Rat Terrier that was born in 1972 in Louisiana whose descendants were bred for hairlessness. Originally registered as a hairless variety of Rat Terrier, in 2004 the United Kennel Club granted the American Hairless Terrier recognition, in 2016 the American Kennel Club followed suit. Many American Hairless Terriers are still born with a coat, recognised as a coated variety.

The American Pit Bull Terrier (APBT) is a purebred dog breed recognized by the United Kennel Club (UKC) and the American Dog Breeders Association (ADBA), but not the American Kennel Club (AKC). It is a medium-sized, intelligent, short-haired dog, of a solid build, whose early ancestors came from the British Isles. When compared with the English Staffordshire Bull Terrier, the American Pit Bull Terrier is larger by margins of 6–8 inches (15–20 cm) in height and 25–35 pounds (11–16 kg) in weight. The American Pit Bull Terrier varies in size: males are normally about 18–21 inches (45–53 cm) in height and around 35–60 pounds (15–27 kg) in weight, while females are normally around 17–20 inches (43–50 cm) in height and 30–50 pounds (13–22 kg) in weight.

The American Staffordshire Terrier, also known as the AmStaff or American Staffy is a medium-sized, short-coated American dog breed.

The Australian Silky Terrier or simply Silky Terrier is a small breed of dog of the terrier dog type. The breed was developed in Australia, although the ancestral types and breeds were from Great Britain. It is closely related to the Australian Terrier and the Yorkshire Terrier. The breed is called the Silky Terrier in North America, but is called the Australian Silky Terrier in its country of origin and in the rest of the world.

The Australian Terrier is a small breed of dog of the terrier dog type. The breed was developed in Australia, although the ancestral types of dogs from which the breed descends were from Great Britain.
The Bedlington Terrier is a breed of small dog named after the mining town of Bedlington, Northumberland in North East England. Originally bred to hunt, the Bedlington Terrier has since been used in dog racing, numerous dog sports, as well as in conformation shows and as a companion dog. It is closely related to the Dandie Dinmont Terrier, Whippet and Otterhound.

The Black and Tan Terrier was a broad breed or type of terrier that was one of the earliest terriers breeds, whilst now extinct it is believed to be the ancestor of all modern Fell Terrier breeds and The Kennel Club recognised Welsh Terrier.

The Black Russian Terrier, also known as the Chornyi Terrier is a breed of dog created in USSR in Red Star Kennel during the late 1940s and the early 1950s for use as military/working dogs. At the present time, the Black Russian Terrier is a breed recognized by the FCI, AKC, CKC, KC, ANKC, NZKC and other cynological organizations. The contemporary Black Russian Terrier is a working dog, guarding dog, sporting and companion dog.

The Border Terrier is a small, rough-coated breed of dog in the terrier group. Bred as a fox and vermin hunter, the Border Terrier shares ancestry with the Dandie Dinmont Terrier and the Bedlington Terrier.
The Boston Terrier is a breed of dog originating in the United States of America. This "American Gentleman" was accepted in 1893 by the American Kennel Club as a non-sporting breed. Color and markings are important when distinguishing this breed from the AKC standard. They should be either black, brindle or seal with white markings. Boston Terriers are small and compact with a short tail and erect ears. The AKC says they are highly intelligent and very easily trained. They are friendly and can be stubborn at times. The average life span of a Boston Terrier is around 11 to 13 years, though some can live up to around 18 years. They have a short nose, which can often cause breathing problems later in life, which is what leads to a low life expectancy.

The Brazilian Terrier is a breed of dog developed in Brazil. It is one of several terriers and one of the two worldwide recognized native breeds of Brazil.

The bull and terrier is an extinct type of dog. It was a crossbreed that was the progenitor of several modern standardised breeds, including the Bull Terrier, Miniature Bull Terrier, Staffordshire Bull Terrier, American Pit Bull Terrier, and American Staffordshire Terrier. Bull and terriers were crossbred primarily from the Old English Bulldog and one or more varieties of Old English Terriers.

The Bull Terrier is a breed of dog in the terrier family. There is also a miniature version of this breed which is officially known as the Miniature Bull Terrier.

Bull-type terriers are a dog sub-type of terriers. It is also a section of the terrier group at the Fédération Cynologique Internationale (FCI). All bull-type terriers share the same ancestry in the crossbreeding between bulldog breeds and terriers.
The Ca Rater Mallorquí is a Spanish breed of dog from the island of Majorca.

The Cairn Terrier is one of the oldest terrier breeds, originating in the Scottish Highlands and recognized as one of Scotland's earliest working dogs. The breed was given the name Cairn because the breed's function was to hunt and chase quarry between the cairns in the Scottish highlands.

The Cesky Terrier is a small terrier type dog originating in Czechoslovakia.
The Chilean Terrier is the first breed of dog from Chile. The breed dates back to the late 19th century, resulting from the crossing of the Smooth Fox Terrier with the Ratonero Bodeguero Andaluz. This dog is recognised by the Kennel Club of Chile (KCC), but is not recognized by the FCI. Since 2011, the breed is classified into Group 3 of Alianz Canine Worldwide (ACW).

A Dandie Dinmont Terrier is a small Scottish dog breed in the terrier family. The breed has a very long body, short legs, and a distinctive topknot of hair on the head. They are friendly but tough, and are suitable for interaction with older children. There are no breed-specific health concerns, but they can be affected by spinal problems due to their elongated body, and the breed is affected by canine cancer at a higher than average rate.

The English Toy Terrier is a small breed of terrier in the toy dog group.

Fell Terrier refers to a regional type of long-legged working terrier, not a specific breed of dog.

The Glen of Imaal Terrier is a breed of dog of the terrier category and one of four Irish terrier breeds. It is sometimes called the Irish Glen of Imaal Terrier or the Wicklow Terrier, and the name of the breed is often shortened by fanciers to just Glen.

The Gos Rater Valencià is a breed of dog that originates in Spain. Recognised by the Real Sociedad Canina de España in 2004, it has had recent success with a member of the breed winning the Spanish National Dog Show in 2011. It is a traditionally docked breed. Its name reflects its main occupation: hunting rats and mice.

The Irish Terrier is a dog breed from Ireland, one of many breeds of terrier. The Irish Terrier is considered one of the oldest terrier breeds. The Dublin dog show in 1873 was the first to provide a separate class for Irish Terriers. By the 1880s, Irish Terriers were the fourth most popular breed in Ireland and Britain.

The Jack Russell Terrier is a small terrier that has its origins in fox hunting in England. It is principally white-bodied and smooth, rough or broken-coated and can be any colour.

The Jagdterrier is a type of working terrier, originating in Germany, that is used for hunting quarry both above and underground. This breed of terrier is also called the German Hunt Terrier.

The Japanese Terrier is a small terrier native to Japan. It is believed to be descended from the progeny of fox terrier types, pointers and indigenous Japanese dogs. This dog is also known as the Nippon Terrier. The breed is rare, even in Japan.

The Kerry Blue Terrier is a breed of dog. Originally bred to control "vermin" including rats, rabbits, badgers, foxes, otters and hares, over time the Kerry became a general working dog used for a variety of jobs including herding cattle and sheep, and as a guard dog. Today the Kerry has spread around the world as a companion and working dog. Despite a Kerry Blue winning Crufts in 2000, it remains an "unfashionable" breed, and is distinctly uncommon; however, it is not as threatened as some of the other terrier breeds such as the Skye Terrier, Sealyham Terrier, and Dandie Dinmont Terrier.

The Lakeland Terrier is a dog breed, which takes its name from its place of origin, the Lake District in England. The dog is a small to mid-size member of the Terrier family. While independent in personality, it interacts well with owners and all family members, and is mostly hypo-allergenic. In the United Kingdom, the Lakeland Terrier is considered a vulnerable dog breed at risk of going extinct through low levels of breeding, according to The Kennel Club. In the United States, the Lakeland Terrier ranked 148 out of 193 breeds by number of American Kennel Club puppy registrations in 2019.
The Lucas Terrier is a small breed of dog of the terrier type which originated in England in the late 1940s. The breed was created by Sir Jocelyn Lucas at his Ilmer Kennels in Watford, Hertfordshire. All living authentic examples can trace their ancestry back to a small number of his original Ilmer Sealyham dogs, and resulting Lucas Terrier progeny.

The Manchester Terrier is a breed of dog of the smooth-haired terrier type. It was first bred in the 19th century to control vermin, notably rats, at which it excelled. So efficient at the task was it that it often appeared in rat-baiting pits until that sport, which had effectively been illegal in the UK since 1835, finally died out at the beginning of the 20th century.

The Miniature Bull Terrier is a breed with origins in the extinct English White Terrier, the Dalmatian and the Bulldog. The first existence is documented 1872 in The Dogs of British Island.

The Miniature Fox Terrier is a small, fine, lightweight working terrier developed as a hunting dog and vermin router. It is known colloquially in its native Australia as the “Mini Foxie”.

The Norfolk Terrier is a British breed of dog. Prior to gaining recognition as an independent breed in 1964, it was a variety of the Norwich Terrier, distinguished from the "prick eared" Norwich by its "drop ears". Together, the Norfolk and Norwich Terriers are the smallest of the working terriers.

The Norwich Terrier is a breed of dog originating in the United Kingdom, and was bred to hunt small rodents. With a friendly personality, Norwich Terriers are today mostly a companion dog breed. One of the smallest terriers, these dogs are generally healthy, but are relatively rare, due in part to their low litter size and the common need for caesarian sections. Their drop-eared variety is the Norfolk Terrier. Recognized as the "official breed of England" in 1932, Norwich Terriers have been delighting owners around the world as a hardworking, loyal companion dogs for nearly a century.

The Parson Russell Terrier is a breed of small white terrier that was the original Fox Terrier of the 18th century. The breed is named after the Reverend John "Jack" Russell, credited with the creation of this type of dog. It is the recognised conformation show variety of the Jack Russell Terrier and was first recognised in 1990 in the United Kingdom as the Parson Jack Russell Terrier. In America, it was first recognised as the Jack Russell Terrier in 1997. The name was changed to its current form in 1999 in the UK and by 2008 all international kennel clubs recognised it under the new name.

The Patterdale Terrier is a breed of dog descended from the Northern terrier breeds of the early 18th century.

The Rat Terrier is an American dog breed with a background as a farm dog and hunting companion. They share much ancestry with the small hunting dogs known as feists. Common throughout family farms in the 1920s and 1930s, they are now recognized by the United and American Kennel Clubs and are considered a rare breed. Today's Rat Terrier is an intelligent and active small dog that is kept both for pest control and as a family pet.

The Ratonero Bodeguero Andaluz is a Spanish breed of dog of the terrier type. Its name reflects its main occupation: hunting rats and mice hidden between barrels in the wineries of Andalusia in Spain. It was recognised as an indigenous Spanish breed in 2000 by the Spanish Ministry of Agriculture and by the Spanish Kennel Club, the Real Sociedad Canina de España.

The Russell Terrier is a predominantly white working terrier with an instinct to hunt prey underground. The breed was derived from Jack Russell's working terrier strains that were used in the 19th century for fox hunting. Russell's fox working strains were much smaller than the Show Fox Terrier and remained working terriers. The size of the Russell Terrier combined with a small flexible, spannable chest makes it an ideal size to work efficiently underground. Their unique rectangular body shape with the body being of slightly longer length than the leg makes them distinctly different from the Parson Russell Terrier and the Jack Russell Terrier of the Jack Russell Terrier Club of America (JRTCA).

The Scottish Terrier, popularly called the Scottie, is a breed of dog. Initially one of the highland breeds of terrier that were grouped under the name of Skye Terrier, it is one of five breeds of terrier that originated in Scotland, the other four being the modern Skye, Cairn, Dandie Dinmont, and West Highland White Terriers. They are an independent and rugged breed with a wiry outer coat and a soft dense undercoat. The First Earl of Dumbarton nicknamed the breed "the diehard". The modern breed is said to be able to trace its lineage back to a single female, named Splinter II.

The Sealyham Terrier is a rare Welsh breed of small to medium-sized terrier that originated in Wales as a working dog. It is principally a white-bodied, rough-coated breed, developed in the mid-to-late-19th century by Captain John Edwardes at Sealyham House, Pembrokeshire.

The Skye Terrier is a breed of dog that is a long, low, hardy terrier and "one of the most endangered native dog breeds in the United Kingdom" according to The Kennel Club.

The Smooth Fox Terrier is a breed of dog, one of many terrier breeds. It was the first breed in the fox terrier family to be given official recognition by The Kennel Club. It is well known, and although not a widely popular breed today outside hunting and show circles, it is extremely significant due to the large number of terriers believed descended from the breed.

The Soft-coated Wheaten Terrier is a pure breed terrier originating from Ireland. Wheatens typically have one of two coat types: Irish or Heavy (American). The Irish coat is generally silkier and wavier than the Heavy, or American coat, which is thicker and fuller. Wheatens are generally friendly and playful, and tend to get along well with children and other dogs.

The Sporting Lucas Terrier is a small breed of dog of the terrier type. The breed is named for Jocelyn Lucas.

The Staffordshire Bull Terrier is a British breed of short-haired terrier of medium size. It originated in the city of Birmingham and in the Black Country of Staffordshire, it is the direct descendent of the Bull and terrier which was itself bred from cross-breeding the Old English Bulldog and the Old English Terrier. The breed’s ancestors were bred primarily for the blood sports of dog fighting and rat-baiting.

The Teddy Roosevelt Terrier is a small to medium-sized American hunting terrier. It is lower-set, with shorter legs, and is more muscular with heavier bone density than the related American Rat Terrier. Much diversity exists in the history of the Teddy Roosevelt Terrier breed, and it shares a common early history with the American Rat Terrier, Fox Paulistinha, and Tenterfield Terrier. The Rat Terrier's background is said to stem from the terriers or other dogs that were brought over by early English and other working-class immigrants. Since the breed was a farm, hunting, and utility dog, little to no planned breeding was used other than breeding dogs with agreeable traits to each other to produce the desired work ethic in the dog. The Feist (dog), Bull Terrier, Smooth Fox Terrier, Manchester Terrier, Whippet, Italian Greyhound, the now extinct English White Terrier, Turnspit Dog, and Wry-legged Terrier all share in the Teddy Roosevelt Terrier's ancestry. These early ratting terriers were then most likely bred to the Beagle or Beagle crossbred dogs and other dogs. Maximizing the influences from these various breeds provides the modern Teddy Roosevelt Terrier with a keen sense of awareness and prey drive, an acute sense of smell. and a very high intellect. Although they tend to be aloof with strangers, they are devoted companion dogs with a strong desire to please and be near their owners at all times.

Developed in Australia, the forebears of the Tenterfield Terrier accompanied British settlers en route to Australia by ship. The forebears of these small dogs had been bred for ratting. This type of dog suited shipboard life, where rats and mice were both a health hazard and a threat to food supplies. Today they are a strong, active, hardy and agile dog, their smooth short coat making them 'easy care' family companions.

Tiny the Wonder was an English Toy Terrier famous in the City of London in the mid-19th century for being able to kill 200 rats in an hour in the city's rat-baiting pits. At the time, the world record for killing 100 rats was 5 minutes, 30 seconds, held by a bull and terrier named Billy.

The Toy Fox Terrier is a small terrier breed of dog, directly descended from the larger Fox Terrier but considered a separate breed.

The Toy Manchester Terrier is a breed of dog, categorized as a terrier. The breed was bred down in size in North America from the Manchester Terrier, and is placed in the Toy Group by the American Kennel Club and the Canadian Kennel Club. Neither the Fédération Cynologique Internationale nor The Kennel Club recognize a Toy variety of the Manchester Terrier.

The Welsh Terrier originates from Wales and was originally bred for hunting fox, rodents and badger, but during the last century it has mainly been bred for showing. Despite this, it has retained its terrier strength of character. The Welsh Terrier has been claimed to be the oldest existing dog breed in the UK according to research.

The West Highland White Terrier, commonly known as the Westie, is a breed of dog from Scotland with a distinctive white harsh coat with a somewhat soft white undercoat. It is a medium-sized terrier, although with longer legs than other Scottish breeds of terrier. It has a white double coat of fur which fills out the dog's face, giving it a rounded appearance.

The Wire Fox Terrier is a breed of dog, one of many terrier breeds. It is a fox terrier, and although it bears a resemblance to the Smooth Fox Terrier, they are believed to have been developed separately.

A working terrier is a small type of dog which pursues its quarry into the earth. According to the Oxford English Dictionary, the name dates back to at least 1440, derived from French chien terrier 'digging dog', from Medieval Latin terrarius, ultimately from Latin terra (earth).