According to the Kennel Club, the English Toy Terrier should be 25–30 cm (10–12 in) in height and 2.7–3.6 kg (6–8 lb) in weight. The only permitted color is black with defined tan markings on the legs, chest and face. The movement is described as being like the extended trot of a horse. Most English toy terriers are lovable, friendly, very loud and love to bark.
The English Toy Terrier (ETT) developed from the Old English Black and Tan Terrier and is closely related to the larger Manchester Terrier. Extremely fast and agile, the origins of this alert terrier are in the world of the rat pit, a sport popular in the cities of Victorian England where terriers were placed in a circle or pit with a number of rats and bets were taken as to which dog would kill its quota of rats in the fastest time. Small dogs were highly prized with the ideal being to produce the smallest dog still capable of killing its quota of rats in as short a time as possible. In 1848 a black and tan terrier weighing just 51⁄2 pounds (2.5 kg) named Tiny is recorded to have killed 300 rats in less than an hour.
The outlawing of this sport coincided with the formation of the Kennel Club. With its elegant appearance the Black and Tan Terrier moved effortlessly into the conformation show ring. At the first ever all breeds dog show there was a very respectable entry of Black and Tan Terriers divided by weight. This weight division continued with two varieties of Black and Tan Terrier until the 1920s when they were split into two breeds, the larger Manchester Terrier and the smaller Black and Tan Terrier (Miniature). The name English Toy Terrier (Black and Tan) was adopted in 1962. Black and Tan Terriers of all sizes were exported to Canada and the USA, founding a population which was largely isolated from the European one until very recently. In North America the two sizes were also split into two breeds until 1958 when declining numbers of the Standard Manchester Terrier prompted the American Kennel Club to re-defined them as a single breed with two varieties; Standard and Toy.
English Toy Terriers in 1894 with another very popular toy dog of the era, the Paisley Terrier
The ETT is on the UK Kennel Club's list of vulnerable native breeds and great effort is being made to boost the popularity of the breed and develop a viable gene pool. The Kennel Club (UK) has opened the stud book, allowing the North American Toy Manchester Terrier to be re-registered as English Toy Terrier (Black & Tan) provided it is certified to be a Toy and not of the Standard variety. Some owners in Great Britain are against this decision; others see it as a positive way to preserve the breed.