The English Cocker Spaniel is a breed of gun dog. The English Cocker Spaniel is an active, good-natured, sporting dog, standing well up at the withers and compactly built. There are "field" or "working" cockers and "show" cockers. It is one of several varieties of spaniel and somewhat resembles its American cousin, the American Cocker Spaniel, although it is closer to the working-dog form of the Field Spaniel and the Springer Spaniel.
Outside the US, the breed is usually known simply as the Cocker Spaniel, as is the American Cocker Spaniel within the US. Due to the breed's happy disposition and continuously wagging tail, it has been given the cute nickname "merry cocker". They can be also dominant and loyal to their companion. Their health issues are typical for a purebred dog breed; however they are closely associated with rage syndrome even though cases are really quite rare. The word cocker is commonly held to stem from their use to hunt woodcock.
Temperment
The English Cocker Spaniel can be stubborn, but can be easily trained and make a good medium-sized family pet. The breed does not like being alone, and will bond strongly to an individual person in a family. Known for optimism, intelligence and adaptability, the breed is extremely loyal and affectionate. They rank 18th in Stanley Coren's The Intelligence of Dogs, being of excellent working/obedience intelligence.
A link between coat colour and temperament has been proposed. This link could be the colour pigment melanin, which is biochemically similar to chemicals that act as transmitters in the brain. A study made by the University of Cambridge involving over 1,000 Cocker Spaniel households throughout Britain concluded that solid colour Cockers were more likely to be aggressive in 12 out of 13 situations. Red/golden Cockers were shown to be the most aggressive of all, in situations involving strangers, family members, while being disciplined, and sometimes for no apparent reason. A study by Spanish researchers at the Autonomous University of Barcelona revealed a similar link between golden Cockers and aggression. Males were also more likely to be aggressive. The study found the English Cocker Spaniel to have the highest level of owner- and stranger- directed aggression compared to other breeds
Working cockers
This breed, like many others with origins as working dogs, has some genetic lines that focus on working-dog skills and other lines that focus on ensuring that the dog's appearance conforms to a breed standard; these are referred to as the "working" (or "field-bred") and "conformation" strains, respectively. After World War II, Cocker Spaniels bred for pets and for the sport of conformation showing increased enormously in popular appeal, and, for a while, was the most numerous Kennel Club registered breed. This popularity increased the view that all Cockers were useless as working dogs. However, for many dogs this is untrue, as even some show-bred Cockers have retained their working instinct.
Today, this breed is experiencing a resurgence in usage as a working and hunting dog. Dogs from working lines are noticeably distinct in appearance. As is the case with the English Springer Spaniel, the working type has been bred exclusively to perform in the field as a hunting companion. Their coat is shorter and ears less pendulous than the show-bred type. Although registered as the same breed, the two strains have diverged significantly enough that they are rarely crossed. The dogs that have dominated the hunt test, field trial and hunting scene in the United States are field-bred dogs from recently imported British lines. Working-dog lines often have physical characteristics that would prevent them from winning in the show ring. This is a result of selecting for different traits than those selected by show breeders. The longer coat and ears, selected for the show ring, are an impediment in the field. Cuban authorities train and use English Cocker Spaniels as sniffer dogs to check for drugs or food products in passengers' baggage at Cuban airports