Rat Terrier

Ana Oliveira
Dr Ana Oliveira (DVM, University of Lisbon)
Photo of adult Rat Terrier

Rat Terriers are small and active dogs with a feisty and cheerful attitude. They were popular in American farms back in the 1920s and 1930s for catching rats and other pests, but their liveliness and high spirits made them a desirable pet, as well. They are terriers and behave as such – stubborn, active, energetic, but always affectionate and loving to their owners, to whom they are truly devoted.

Because Rat Terriers are the result of multiple crossbreedings, they are sturdy, generally healthy, and long-lived. They are quick and intelligent and because they have good instincts and are easily trained, they are a good choice to be used as service and search dogs. The Rat Terrier is a people dog, friendly with children and forever playful.

About & History

Rat Terriers are named after their working ability and purpose of catching rats. The oldest record of a dog with such a job goes back to the 16th century with records mentioning a rat-catching mongrel that travelled aboard “Mary Rose”, an English flagship sunk in 1545. It is known that the ancestors of the Rat Terrier were brought to the United States by British workers migrating to America and were used to catch rats, squirrels, and other small animals.

By then, Rat Terriers were bred for speed. Their popularity increased in the end of the 19th century and they became known as “feists”. In the 1910s and 1920s, new strains were added to these feists by crossbreeding them with Toy Fox Terriers that were considered too big for the breed standards, which contributed to a decrease in the Rat Terrier’s size. Several crossbreedings with Fox Terriers, Bull Terriers, Manchester Terriers, and the now extinct Old English White Terriers are believed to have taken place and to make up today’s Rat Terriers.

In the Midwest of the United States, Rat Terriers were crossbred with Whippets and Italian Greyhounds in an attempt to make them quicker, more versatile, and thus more adapted to the task of catching preys, especially hares, as farmers were facing a hare problem in the 1920s and 1930s. In Southern and Central parts of the United States, however, Rat Terriers were mixed with Beagles, to improve their sense of smell and make them more pack-oriented.

By the fifties, with the technological improvements in agriculture and the increased use of pesticides, Rat Terriers began to lose their importance, as they were not needed anymore, and began to disappear. Later, in the 1970s, they started to regain their popularity when a fancier of the breed, Milton Decker, bred a new strain of Rat Terriers, the Decker Rat Terriers. These had a fixed ear set, were larger, and were used for hunting larger animals, such as pigs, deer, cougars, and even bears. Another type of Rat Terrier appeared in 1972 when a hairless dog was intentionally bred – called the American Hairless Terrier, which was a miniature Rat Terrier with no hair.

Rat Terriers were only recognised by the American Kennel Club in 2013, though they had been used in competitions before that. They are usually good in agility, flyball, and coursing competitions in regard to sports. Rat Terriers are also used by the police as contraband search dogs, due to their small size and trainability, and as service dogs, aiding in the treatment of people with depression and assisted living.


Rat Terrier Large Photo

Small but robust, Rat Terriers vary when it comes to their colouring. Their classic coat colour is black tricolour, though they can be:

  • White
  • Black with tan
  • Black with rust
  • Black and white
  • Red
  • Lemon
  • Blue
  • Chocolate
  • Orange

Their coat is short, smooth, and dense, and they may have markings, such as intermittent spots. Usually, all Rat Terriers have white markings.

Rat Terriers are small-to-medium sized dogs, may weigh from 4.5 to 11.3 kg (10-25 lb), and measure 33 to 40 cm in height (13-16 inches). Decker Rat Terriers are larger, with males measuring up to 48 cm (19 inches) and weighing from 10 to 18 kg (22-40 lb). Miniature Rat Terriers measure up to 38 cm (15 inches) and weigh between 4.5 and 8 kg (10-18 lb). Toy Rat Terriers are even smaller, measuring up to 30 cm (12 inches) and weighing from 2.3 to 4.5 kg (5-10 lb).

Character & Temperament

Rat Terriers are funny little dogs, full of energy, inquisitive and happy. They have the typical Terrier behaviour in that they love exercise and digging – though they can also be couch potatoes and love to sleep with their owners. They tend to be quite stubborn and fearless, always looking to serve their own interests. Nevertheless, they love to please and will always follow their owners around the house, being quite perceptive and intuitively responding to their moods.

Rat Terriers get along well with children, especially from their family, though their family’s friends are usually their friends, as well. In general, they tend to be wary of strangers and need time to get acquainted and to warm up with people they do not know. This feature makes them good watchdogs and the fact they have an instinct to bark surely helps. They are also friendly with other animals if correctly socialized, but they do have a prey drive, since they were used to catch rats in the past, so they will chase small prey, if given the opportunity. Because they can jump quite high and dig, attention should be given if they are left on their own in a yard – even if fenced. For the same reason, off the leash walks are not always recommended.

When raised with other animals and exposed to different situations and people at an early age, Rat Terriers will be nice to other pets, although there may be some disagreements over food or sleeping places, especially with same-sex dogs. They are extremely playful and will most certainly approach other dogs to play, so it is important to watch out for aggressive dogs, as Rat Terriers will fight back if attacked, completely ignoring any disadvantage their size may carry.

Quick to react, clever, impulsive, and usually bossy, the Rat Terrier has an interesting personality, which makes it either loved or disliked. What some may consider as lively and laughable traits, others consider as “bad habits”. Rat Terriers can be intense and need lots of exercise to vent their energy. They need mental stimulation too, as they may become bored quite easily, and having a special place in the garden where they can dig as much as they want will make them satisfied and prevent destructive behaviours around the house. They will benefit from an experienced and firm owner, as they need a consistent and confident pack leader to keep their feisty attitude under control and their stubbornness kept to a minimum.


Photo of Rat Terrier puppy

Rat Terriers are clever dogs that will respond to food and praise as training rewards. It is important to expose them to different people, situations, sounds, animals, and experiences, as a way to make them socially fit and well-behaved around other people and animals. When not correctly socialized, the Rat Terrier may become aggressive towards strangers and other animals, as they are instinctively wary of other people and have quite an independent temperament.


Rat Terriers can live between 13 and 18 years and are generally healthy. However, they may develop a few health problems, which include:

  • Allergies – Rat Terriers may be prone to allergies, which cause itchy skin and may develop into bacterial skin infections. An allergic dog will tend to scratch a lot, which will make its skin red and, if severe, may lead to lesions.
  • Hip dysplasia – Hip dysplasia affects the hip articulation and happens when the bone does not fit the articulation properly. This causes tension and inflammation of the hip, leading to pain and lameness.
  • Patellar luxation – Common in small dogs, patellar luxation is the dislocation of the knee joint. When sliding out of its place, it causes pain and lameness. Though some dogs with this condition live relatively normal lives, others may have to go under surgery to correct the problem.
  • Malocclusion – Malocclusion is a misaligned jaw or incorrect bite that happens due to deformities of the jaw. It may be the upper jaw extending past the lower, the lower jaw extending out past the upper (prognathism), or one side growing faster than the other, leading to the twisting of the mouth (wry mouth). When extreme, this condition leads to difficulties when eating and grasping and overall discomfort.
  • Demodicosis – Demodicosis, or demodectic mange, is an inflammatory skin disease caused by the Demodex mite, occurring when the dog has a compromised immune system or is weakened. These mites live in the dog’s hair follicles causing loss of hair, redness of the skin, itching, scaling, and lesions. It cannot be passed to humans and it is usually localized in specific regions of the body, occurring in patches on the legs, face, and trunk, but can become widespread, appearing all over the body. It is treatable but when serious it may take several months for a dog to completely recover from the lesions and having its hair grown back.

Exercise and Activity Levels

Rat Terriers need a lot of exercise. They love running, playing, and especially digging. They are also good swimmers and will enjoy any type of game that requires activity. Although they are good to keep in an apartment, they need at least 40-minutes of exercise every day. If not given the right amount of activity they need, Rat Terriers may display destructive behaviours, such as chewing on objects and barking. Apart from physical stimulation, they need mental stimulation too, as they are intelligent dogs, becoming bored when not provided with such stimuli. They are people-oriented and will be satisfied with any activity involving their owners and some kind of movement – be it indoors or outdoors.


The Rat Terrier is an easy pet to keep in terms of grooming. With its short coat they do not require much besides a weekly brushing with a soft brush. They shed little – only in Spring in Autumn – and brushing should be adjusted accordingly. They are easy maintenance dogs, but it is important to examine them regularly, especially their paws, as they are quite sensitive and getting used to being touched and handled will help in future situations, as in the vet consultation. Checking their ears, trimming their nails, and overall examinations can be rewarded with praise, which they love, and that will make them more tolerant to handling.

Famous Rat Terriers

Famous Rat Terriers from popular culture include:

  • The Rat Terrier appearing next to the actress Shirley Temple in the American film “The Little Colonel” (1935).
  • The Rat Terrier mentioned in the book “To Kill a Mockingbird” by Harper Lee.


Product of many crossbreedings themselves, Rat Terriers are mixed with other breeds, resulting in the following cross-breeds:

  • Bluetick Rat Terrier – Cross between a Rat Terrier and a Bluetick Coonhound
  • Brat – Cross between a Rat Terrier and a Boston Terrier
  • Foxy Rat Terrier – Cross between a Rat Terrier and a Toy Fox Terrier
  • Jack Rat Terrier – Cross between a Rat Terrier and a Jack Russell Terrier
  • Mini Ratzer – Cross between a Rat Terrier and a Miniature Schnauzer
  • Pomerat – Cross between a Rat Terrier and a Pomeranian
  • Puggat – Cross between a Rat Terrier and a Pug
  • Raggle – Cross between a Rat Terrier and a Beagle
  • Rashon – Cross between a Rat Terrier and a Bichon Frise
  • Rat Pinscher – Cross between a Rat Terrier and a Miniature Pinscher
  • Rat-A-Pap – Cross between a Rat Terrier and a Papillon
  • Rat-Cha – Cross between a Rat Terrier and a Chihuahua
  • Ratese – Cross between a Rat Terrier and a Maltese
  • Ratshi Terrier – Cross between a Rat Terrier and a Shih Tzu
  • Ratshire Terrier – Cross between a Rat Terrier and a Yorkshire Terrier
  • Rattle – Cross between a Rat Terrier and a Poodle
  • Rattle Griffon – Cross between a Rat Terrier and a Brussels Griffon
  • Toy Rat Doxie – Cross between a Rat Terrier and a Dachshund

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