Rat Terrier

Classification and Varieties

The Rat Terrier is traditionally regarded as much as an adaptable working phenotype as a closed purebred strain, having evolved through diverse agricultural crossbreeding rather than from a narrow ancestral stock.^[3] One dog breed encyclopedia describes three size varieties: standard, miniature and toy.

Size Divisions and Weight Standards

The United Kennel Club and the American Kennel Club divide the breed into two varieties, standard (also called medium) and miniature.^[8][9][10] The standard variety encompasses dogs standing between 33 and 45.5 centimeters (13 to 18 inches) in height, whereas the miniature variety consists of specimens measuring 33 centimeters (13 inches) or less, generally starting from 25 or 25.5 centimeters.^[11] The Finnish Kennel Club describes the miniature height as 25.5 to 33 centimeters and the standard height as 33 to 45.5 centimeters.^[11] The miniature strain has grown in popularity as an indoor companion while retaining its functional role as an earthdog suited to pursuing rodents into tight burrows inaccessible to larger animals.^[1][3]

Adult body weight is recorded between 4.5 and 11.3 kilograms (10 to 25 pounds). In Italy, males are documented as reaching 36 to 46 centimeters in height and 7 to 11 kilograms in weight, while females reach 25 to 38 centimeters and 4 to 7 kilograms. Japanese standards cite medium dogs as measuring 46 centimeters or under with a weight of 3 to 3.5 kilograms, while miniature dogs measure 33 centimeters or under with a weight of 2 to 3 kilograms.^[8][9] By contrast, Vietnamese sources cite the standard variety as measuring 35 to 58 centimeters in height and 5 to 16 kilograms in weight, with a smaller miniature line standing at 20 centimeters and weighing 3 to 4 kilograms.

Beyond the standard and miniature divisions, the National Rat Terrier Association recognizes two additional categories: a toy variety and the Decker Giant. The toy variety includes mature terriers weighing 4.5 kilograms (10 pounds) or less. The Decker Giant is a larger hunting type, often exceeding 11 kilograms in body weight. It is named after the breeder Milton Decker, who developed it as a larger hunting companion. The National Rat Terrier Association recognizes the Decker as a variety, while the American Kennel Club and the United Kennel Club do not recognize it as a separate breed and regard it as a type within the Rat Terrier breed. The Decker Hunting Terrier Registry was established specifically to maintain the physical traits and hunting capabilities of this strain.

Related Lines and Derived Breeds

The Rat Terrier has given rise to several specialized offshoot breeds through selective breeding programs.^[12][13] In the early development of the breed, selective outcrossing produced two distinct structural profiles: a long-legged type and a short-legged type.^[13] The long-legged dogs retained the primary designation of American Rat Terrier, while the short-legged dogs became known as the Teddy Roosevelt Terrier.^[13] The National Rat Terrier Association continues to categorize the Teddy Roosevelt Terrier as a sub-type of the Rat Terrier, designating it as Rat Terrier Type B, whereas other major kennel clubs classify it as an independent breed.^[12]

During the 1970s, a spontaneous mutation producing hairlessness appeared within purebred Rat Terrier litters.^[12] Breeders isolated and propagated this genetic line, resulting in the development of the American Hairless Terrier, which is now recognized as a separate breed by multiple canine organizations.^[12] The Rat Terrier is not bred in the Czech Republic, while the American Hairless Terrier, which was bred from it, is fairly common in Central Europe. Additionally, miniature strains that diverged early from foundation Rat Terrier lines were registered by the United Kennel Club as the Toy Fox Terrier starting in 1936.

History and Origins

The historical foundations of the Rat Terrier reflect centuries of practical selection for vermin eradication and small-game hunting across Great Britain and North America.^{[1][3][14][15][16]} Originating among working-class communities, these dogs were prized for their intense predatory drive, rapid reflexes, and physical endurance.^[1][3][17]

Early Ratting Dogs and British Roots

The earliest known archaeological record of an ancestor performing the duties of a rat terrier is associated with Hatch, a small dog whose skeletal remains were recovered from the Mary Rose, the Tudor flagship of King Henry VIII.^[14][15] The warship sank in 1545 and was raised from the seabed in 1982, though Czech documentation dates the sinking to 1514.^[14][15] Hatch is believed to have been an agile mongrel brought aboard by the crew to suppress the ship's rat population and protect stored provisions.^[14][15]

From the 1820s onward, breeders in Great Britain began intentionally crossing Smooth Fox Terriers and Manchester Terriers to develop specialized dogs for the blood sport of rat-baiting.^{[8][13][16][17]} The White English Terrier and the Bull Terrier were also incorporated into these crosses.^[8][18] In these contests, held in small circular enclosures known as rat pits, wagers were placed on how many rats a single terrier could kill within a specified time limit, typically within sixty seconds.^[16] Speed of reaction and of movement was the main criterion in breeding. According to one source, during a competition in England a single terrier killed 2,501 rats over a seven-hour period in a rat-infested barn, an average of one rat every ten seconds.^{[13][19][20][21]}

Arrival and Development in the United States

During the late nineteenth century, British working-class immigrants transported these rat-baiting terriers to the United States.^[16] At the time of their arrival around the 1890s, the dogs still retained their original black-and-tan coloration.^[16] In North America, the focus of the breed shifted from urban sporting pits to rural agricultural utility.^[1] American farmers required a versatile animal capable not only of controlling barnyard rodents but also of trailing and catching small game such as squirrels and cottontail rabbits.^[1][3][22]

To adapt the dogs to North American terrain, breeders introduced several external breeds into the genetic foundation.^[17] Crosses with Beagles enhanced scenting capabilities and stamina, while introductions of the Whippet and Italian Greyhound contributed sprinting speed and refined athletic conformation.^[16] Crosses with the Smooth Fox Terrier were repeated, establishing the dominance of white-pied coat patterns across the population.^[16] The Miniature Pinscher and Chihuahua were probably also added to reduce size, and crosses with the Greyhound are also recorded. These crosses produced a dog with a milder character but strong hunting instincts.

The resulting dogs were closely aligned with the regional hunting dogs known throughout the American South and Midwest as feists.^{[1][2][3][22]} Foundation Rat Terriers were often visually indistinguishable from mixed-breed feists, sharing a collective working ancestry as multi-purpose treeing and squirrel dogs.^{[1][3][13][22]}

Farm Prominence, Theodore Roosevelt, and Decline

Several sources state that the breed was named by or after United States President Theodore Roosevelt, who kept these terriers as favourite dogs and often took them hunting.^[13][16] One of Roosevelt's terriers became known for killing the rats in the White House.

Between 1910 and 1940, the Rat Terrier became one of the most common dogs found on rural American family farms.^[1][3][23] They served as homestead sentinels and barnyard exterminators, keeping feed stores, grain bins, and poultry enclosures free from destructive vermin.^[1][3][10] Their popularity peaked during the 1920s and 1930s, when nearly every smallholder farm maintained ratting terriers.^[1][3]

Beginning in the 1950s, the breed experienced a severe numerical decline. The widespread use of chemical pesticides, the growth of commercial agriculture and the spread of baits and poison pellets led to this decline. By the late twentieth century, the once-ubiquitous farm dog had become comparatively rare.^[1][3][4]

Preservation and Contemporary Resurgence

Breed loyalists maintained the bloodline, which led to the modern Rat Terrier, and several private associations have kept registries of the breed for some decades. Breed clubs, most notably the Rat Terrier Club of America, were formed to coordinate breeding strategies and advocate for formal registry recognition.^[13] The breed's genetic diversity contributes to its overall health, hardiness and intelligence.

Physical Characteristics

The Rat Terrier presents an athletic, muscular, and compact silhouette characterized by clean lines, functional substance, and complete absence of exaggerated features.^[11] Its anatomical proportions emphasize agility, physical stamina, and rapid acceleration.^[11]

Conformation and Build

The overall build of the Rat Terrier is solid, muscular, and sinewy while retaining elegance and flexibility.^[11] The body is slightly longer than it is tall at the withers, presenting a level topline, a compact back, and a gently rising underline with a moderate tuck-up.^[11] The chest is long and oval rather than barrel-shaped, providing adequate lung room without hindering movement in burrows, accompanied by broad shoulders and a deep brisket.^[11] Compared to the Parson Russell Terrier, the Rat Terrier exhibits finer bone structure and a cleaner, more refined outline.^[24] The legs are tall, straight and slim, and the hind legs are muscular with strong thighs.

Head, Facial Structure, and Ears

The head forms a blunt wedge shape when viewed from the front or in profile, possessing a moderately broad skull that remains relatively flat between the ears.^[11] The stop is clearly defined but never abrupt or exaggerated.^[11] The muzzle is slightly shorter than the cranial skull, tapering smoothly toward the nose, with a lean and elongated profile.^[11] The nose leather matches the primary coat coloration and is never flesh-colored.^[11] The lips are clean and tight, with black, pink, or spotted pigmentation.^[11] A complete scissor bite is standard, though a level bite is fully acceptable under Finnish Kennel Club rules.^[11]

The eyes are oval and set slightly obliquely, conveying an alert and keen expression.^[11] Eye color typically ranges from hazel to dark brown, though grey eyes are permitted in blue-coated individuals.^[11] The ears are V-shaped, moderately pointed, and set high on the skull.^[11] Ear carriage varies across individuals; standards accept fully erect ears, semi-erect ears, and tipped or folded button ears, all of which lend an attentive, animated appearance to the face.^[11][24]

Tail Carriage and Bobtail Traits

The Rat Terrier exhibits multiple tail configurations, ranging from full-length natural tails to natural bobtails.^[11] The bobtail gene is very common in Rat Terriers and can produce puppies with varying tail lengths. The tail was traditionally docked to 5.1 to 7.6 centimeters (2 to 3 inches). In the United States, long tails are usually docked.^[11] In contemporary practice, docking is less universal, and natural, undocked tails are fully permitted by official breed standards and preferred by many modern breeders.^[11]

Coat Texture and Pigmentation

The coat of the Rat Terrier is a short, single, smooth coat that lies flat against the body, displaying a natural gloss and dense texture.^[11] The breed standard specifies that the coat must always incorporate white, appearing as a piebald, bi-color, or tri-color pattern with varying distribution of colored patches.^[11][25] Solid white coats are also recognized as permissible under the Finnish Kennel Club standard.^[11]

Permissible patch colors encompass a broad spectrum, including black, chocolate, red ranging from pale gold to dark mahogany, blue, grey Isabella (pearl), lemon, cream, and apricot.^[11][25] The classic coloring, known as black tricolor, is black patching with tan markings, always with some white.^[11][25] A sable overlay may appear across any of these colors.^[25] Another traditional markings pattern is the badger marking, in which tan points on the muzzle blend across the face up to the forehead while solid tan covers the legs and underbelly.^[25] Ticking, characterized by small pigmented spots or flecks, is commonly visible across white coat sections or on the underlying skin.^[25]

Color Controversies

Coat coloration has been a subject of ongoing debate among breed organizations and fanciers.^[26] The brindle pattern represents a point of regulatory divergence. In Russian breed documentation, brindle is currently prohibited under major kennel club standards, though several breeders consider it a traditional coat pattern and actively campaign for its official inclusion.^[26] In contrast, Portuguese documentation states that brindle is currently permitted by the breed standards.

The merle coat pattern is widely rejected by Rat Terrier breed clubs and breeders.^[26] Merle coloration in the breed is considered the result of recent crosses with other breeds.^[26] Health problems associated with the merle gene are given as the reason most Rat Terrier breeders reject it.^[26]

Temperament and Behavior

The Rat Terrier possesses a keen, inquisitive, and cheerful disposition, pairing high working intelligence with strong loyalty toward its human family.^[1][3][24] The breed is a true terrier in character: intelligent, stubborn, adaptable and persistent. It is also described as obedient and easy to train.^{[1][3][11][24]}

Personality Traits and Intelligence

Rat Terriers are energetic, attentive, and determined dogs with a notable capacity for independent problem-solving.^[1][3][11] Georgian descriptions call the breed a highly energetic, tireless dog and compare its character to that of a Jack Russell Terrier 'squared'. They possess an eager desire to please their handlers, which makes them receptive to positive training techniques and fast learners in various disciplines.^[24] When properly stimulated, they are calm and affectionate household companions, but without adequate mental tasks and daily exercise, their high energy can manifest in boredom and stubborn mischief.^[1]

Rat Terriers adapt easily to their owner's way of life, in a large city or a village; the miniature variety suits apartment living, while larger dogs need intensive exercise outdoors. They tolerate both warm and cold weather conditions effectively. Rat Terriers need walks and exercise every day, and they also like to swim.

Socialization and Family Life

The social sensitivity of Rat Terriers means that they need thorough socialization from an early age. Proper socialization of a puppy includes meeting a wide range of people and places, especially during the first three months of life, as well as other dogs, other animals and vehicles. With proper training as puppies, Rat Terriers are usually loyal to their owners and respectful toward people.

Rat Terriers become attached to their owners easily and are described as affectionate.^[11][24] They get along well with children, are usually kind and friendly toward them, and are playful dogs. However, Vietnamese sources describe them as rather boisterous with small children and advise care when very young children play with them.

Interactions with Other Animals and Play Habits

Rat Terriers typically interact peacefully with other dogs, displaying less territorial aggression and intraspecific conflict than Jack Russell Terriers.^[11] However, Italian breed documentation notes that during play Rat Terriers sometimes overdo their biting, especially when two females play together or when they play with a larger dog.

Watchdog Behavior

Rat Terriers have also been used as watchdogs, and the breed is described as alert.^[10][11] Although they may initially display polite reserve toward unfamiliar visitors, they quickly differentiate friends from potential threats and adopt a welcoming attitude toward people recognized by their owners.^[11]

Working Roles and Activities

While the Rat Terrier was originally created for vermin suppression and small-game hunting on family farms, the modern breed demonstrates versatility across a diverse spectrum of utilitarian, social, and competitive pursuits.^{[1][3][7][14]} Its high intelligence, compact frame, and tractable temperament have facilitated its transition into modern service roles.^[1][3][7]

Agricultural Pest Control and Hunting

The traditional occupation of the Rat Terrier remains pest eradication.^[3][22] The breed is an efficient killer of rats, mice, and other agricultural rodents, protecting farm buildings, granaries, and poultry coops from contamination and loss.^[3][10]

In addition to rodent control, the Rat Terrier functions as an effective hunting dog for small game.^[1][3][22] They are particularly skilled at locating and treeing squirrels, pursuing quarry up trees and signaling hunters through persistent barking, earning them the historical title of squirrel dogs.^[13] In North America, where breeders developed larger strains like the Decker Giant, Rat Terriers have also been used to track and hunt cottontail rabbits, hares, raccoons, and even deer.^[17]

Therapy and Community Service

Law Enforcement Detection Work

Police departments and security agencies in the United States have utilized Rat Terriers as specialized search dogs for locating illicit narcotics and contraband.^[7] Because of their high working intelligence, Rat Terriers can master scent detection certification programs in approximately three weeks, representing a considerably shorter training cycle than is customary for traditional police breeds such as the German Shepherd Dog.^[7]

The diminutive stature of the Rat Terrier offers operational advantages during detailed searches.^[7] Unlike heavy patrol dogs that can tear automobile upholstery, scratch surfaces, or overturn domestic furnishings during inspections, a Rat Terrier can thoroughly search tight vehicle compartments, private homes, and narrow prison cells without causing physical damage.^[7] This also reduces the chance of large financial compensation to the owner of searched property when a search finds nothing.^[7]

Dog Sports and Companion Competitions

Rat Terriers are energetic competitors in formal canine performance sports, including agility, formal obedience, and rally trials.^[5][27]

When the American Kennel Club integrated the breed into sanctioned competition, Rat Terriers were initially authorized to enter AKC Companion events starting on January 1, 2006.^[5][27] The first Rat Terrier to achieve a certified title under American Kennel Club sanction was Harpur's Giddy Upp, known as Gigi, handled by D. Davidson Harpur in an agility trial conducted in Van Nuys, California, on January 14, 2006.^[5][27]

Health and Care

Owing to a long history of regular outcrossing to unrelated working breeds, the Rat Terrier enjoys substantial genetic variability, rendering it an inherently hardy, sound, and robust dog.^[28]

Inherited Conditions and Health Screening

Despite its overall hardiness, some health issues have become more common as the breed has grown in popularity in recent years.^[28][29] To mitigate these risks, the Canine Health Information Center recommends health testing protocols for breeding stock, advising screenings for patellar luxation, cardiac abnormalities, pancreatic disorders, hip dysplasia, and Legg-Calve-Perthes syndrome.^[28][29]

The emergence of joint disorders such as patellar luxation and hip dysplasia is considered unusual by canine specialists, as hip dysplasia is predominantly associated with large, heavy working breeds such as the German Shepherd Dog or Labrador Retriever rather than small terriers.^[28] Responsible breeding programs utilize orthopedic radiographs and cardiac clearances prior to breeding to maintain soundness.^[28]

Longevity Expectations

The lifespan of the Rat Terrier is generally extensive, reflecting its resilient constitution, though published longevity figures vary across editions.^[28] Russian and Hebrew sources state that a well-cared-for Rat Terrier lives an average of 16 to 19 years.^[28] Czech texts note a normal lifespan of 15 to 20 years, though its accompanying data box gives 14 to 15 years.^[28]

Care and Grooming

The Rat Terrier has a short, smooth and glossy coat.^[11] Exercise requirements are moderate to high, requiring daily walks, running opportunities, and interactive play sessions to meet the breed's physical and mental needs.^[1]

Breed Recognition and Registries

Multiple kennel clubs, independent registries, and international associations have adopted different approaches to registration, standards, and recognition.^[3][18][30]

North American Kennel Clubs and Registration Debates

The United Kennel Club officially recognized the Rat Terrier as a distinct purebred breed on January 1, 1999.^[3][5][27]

The American Kennel Club authorized the Rat Terrier to enter sanctioned companion events, such as agility and obedience, starting on January 1, 2006.^[5][27] The club granted full breed recognition on July 1, 2010, initially assigning it to the Miscellaneous Class.^{[3][5][10][27]} In June 2012, the American Kennel Club transferred the Rat Terrier into the Terrier Group.^[10] The Rat Terrier Club of America serves as the official parent club representing the breed within the American Kennel Club.

The drive toward conventional kennel club recognition encountered resistance from independent registries. The National Rat Terrier Association is the largest independent organization maintaining pedigree records and studbook registrations, having tracked bloodlines for several decades. Out of concern for the working qualities of the terrier, the association is the most prominent of the clubs and associations that oppose the American Kennel Club's strict breeding rules and purebred selection.

Nordic and International Status

In Northern Europe, the Finnish Kennel Club (Suomen Kennelliitto) officially recognized the Rat Terrier in 2016.^[30] That same year, the Swedish Kennel Club (Svenska Kennelklubben) and the Nordic Kennel Union recognized the breed, granting it official show exhibition eligibility beginning in 2017.^[18] In Sweden, the breed club for the Rat Terrier and American Hairless Terrier (Rasklubben för Rat- och American Hairless Terrier) represents the breed under the Swedish Terrier Club and the Swedish Kennel Club.^[18]

The Rat Terrier is not recognized by the Federation Cynologique Internationale (FCI).^[30] Outside the United States, the breed remains rare, and established breeding populations do not exist in countries such as the Czech Republic.^[4]

References

1. Kane, Alice J. Rat Terrier: a Comprehensive Owner's Guide. Kennel Club Books, 2004.
2. Kane, Alice J. (1 September 2003). Rat Terrier: Special Limited Edition: A Comprehensive Owner's Guide [Terier Tikus: Edisi Terhad Khas: Panduan Komprehensif Pemilik] (dalam bahasa Inggeris). Allenhurst, New Jersey, Amerika Syarikat: Kennel Club Books. ISBN 9781593783679. OCLC 53127810. | //www.worldcat.org/oclc/53127810
3. Kane, Alice J. Rat Terrier: a Comprehensive Owner's Guide. — Kennel Club Books, 2004.
4. Sipe, Roger (editor). Popular Dog Series Vol. 2006
5. AKC Gazette March 2006 page 16
6. Sipe, Roger. Popular Dog Series. — Vol.43. — 2006.
7. Rat Terrier Breed Information, Characteristics & Heath Problems (брит. англ.). DogZone.com. Дата обращения: 27 ноября 2019. Архивировано 27 ноября 2019 года.
8. 藤原尚太郎『日本と世界の愛犬図鑑 最新版』辰巳出版、2013年、236ページ。
9. ブルース・フォーグル著『新犬種大図鑑』によれば、スタンダード、ミニチュア、トイの3段階があり、それぞれ体高36～56cm、体重5～16kg、体高20～36cm、体重2.5～3.5kg、体高20cm以下、体重2～2.5kgという（293ページ）。ただし、ラット・テリアを公認しているアメリカンケネルクラブやユナイテッドケネルクラブではミディアムとミニチュアの2種類に分けている（UKCスタンダード・AKCスタンダード）。
10. Rat Terrier. American Kennel Club. Haettu 1.2.2019.
11. Amerikanrottaterrieri: Rotumääritelmä. Suomen Kennelliitto. Haettu 1.2.2019.
12. Стандарт АКС .
13. デズモンド・モリス著、福山英也監修『デズモンド・モリスの犬種事典』誠文堂新光社、2007年、182ページ
14. Irvine, Chris. "Mary Rose's dog unveiled for the first time". The Telegraph.
15. Irvine, Chris. Mary Rose's dog unveiled for the first time. — The Telegraph.
16. Bonnie Wilcox, Chris Walkowicz: Kynos-Atlas Hunderassen der Welt. Band 2. Kynos Verlag, Mürlenbach/Eifel 1993, ISBN 3-924008-93-0, Rat Terrier, S. 714, 715.
17. ブルース・フォーグル著、福山英也監修『新犬種大図鑑』ペットライフ社、2002年、293ページ。
18. ”NKU välkomnar tre nya hundraser”. pressrelease Svenska Kennelklubben (SKK) 24/10 2016. Arkiverad från originalet. https://web.archive.org/web/20161025044854/http://www.skk.se/sv/nyheter/2016/10/NKU-valkomnar-tre-nya-hundraser/.
19. Wilcox, Bonnie; Walkowicz, Chris (1995). "Rat Terrier". The Atlas of Dog Breeds of the World (5th ed.). Neptune, New Jersey: TFH Publications. pp. 714–715. ISBN 9780793812844.
20. Wilcox, Bonnie, DVM; Walkowicz, Chris (1993). Rat Terrier. The Atlas of Dog Breeds of the World. Vol. 2 (4th ed.). Neptune, New Jersey: T.F.H. pp. 714–715. ISBN 0-86622-873-X. ISBN 0-86622-855-1.
21. Wilcox, Bonnie; Walkowicz, Chris (1995). "Rat Terrier" [Terier Tikus]. The Atlas of Dog Breeds of the World [Atlas Baka Anjing di Dunia] (dalam bahasa Inggeris) (ed. ke-5). Neptune City, New Jersey, Amerika Syarikat: TFH Publications. m/s. 714–715. ISBN 9780793812844. OCLC 32596861. | //www.worldcat.org/oclc/32596861
22. Padrão oficial da raça pelo United Kennel Club (em inglês)
23. AKC: Rat Terrier History (Memento des Originals vom 22. Oktober 2008 im Internet Archive) Info: Der Archivlink wurde automatisch eingesetzt und noch nicht geprüft. Bitte prüfe Original- und Archivlink gemäß Anleitung und entferne dann diesen Hinweis.@1@2Vorlage:Webachiv/IABot/www.akc.org
24. Sissi Schrott: American Rat Terrier Rassebeschreibung. In: dogbible.com. 27. Mai 2022, abgerufen am 27. Mai 2022.
25. Rat Terrier Club of America - Color Codes & Patterns . ratterrierclubofamerica.org. Дата обращения: 26 ноября 2019. Архивировано 8 мая 2019 года.
26. vetguide . www.nrta.com. Дата обращения: 26 ноября 2019. Архивировано 27 июня 2016 года.
27. AKC Gazette (dalam bahasa Inggeris). 123. New York, New York, Amerika Syarikat: American Kennel Club. Mac 2006. m/s. 16.
28. "Rat Terrier". Canine Health Information Center website. Retrieved 14 September 2013.
29. "Rat Terrier" [Terier Tikus] (dalam bahasa Inggeris). caninehealthinfo.org. Diarkibkan daripada yang asal pada 26 September 2013. Dicapai pada 26 Mac 2024.
30. Amerikanrottaterrieri. KoiraNet-Jalostustietojärjestelmä. Haettu 6.6.2020.