Cocker Spaniel refers to two different breeds of dogs of the Spaniel dog type, both of which are commonly called simply Cocker Spaniel in their respective countries of origin. They were originally bred as gun dogs, using their noses to methodically cover low areas near the handler to flush ground-dwelling birds into the air. They then use their eyes to follow the bird to where it lands, then using their noses if necessary, gently pick up the bird and drop it somewhere near the handler.
American Cocker Spaniel
The American Cocker Spaniel is a medium size breed of dog. It's one of the Spaniel type breeds, similar to the English Cocker Spaniel, and was originally bred as a gun dog. In the United States, the breed is usually referred to as the Cocker Spaniel, while in Canada and elsewhere in the world, it's called the American Cocker Spaniel. The word cocker is commonly held to stem from their use to hunt woodcock in England. Although the Cocker Spaniel type originated in the United Kingdom, by the 1940s the American breed was recognized as distinct from the English breed.
English Cocker Spaniel
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.