While it's certainly possible to breed an American cocker spaniel with an English cocker spaniel, the resulting litter cannot be registered by the American Kennel Club. The AKC recognizes the American and English cocker spaniels as distinct types. AKC registration papers for American cocker spaniels list the breed as "cocker spaniel" while the other is listed as "English cocker spaniel."
American Cocker Spaniels
The American cocker spaniel originated as a hunting breed, although few participate in that activity in modern times. Small and active, this dog requires regular grooming of its silky coat. Considered a sporting breed by the AKC, it is the smallest breed in that category. The breed standard notes that the American cocker spaniel's expression is intelligent, soft and alert.
English Cocker Spaniel
More popular worldwide than the American version, although far fewer in number in the United States, the English cocker spaniel usually retains more of its hunting instinct than the American. Working hunting dogs may qualify for certificates from the English Cocker Spaniel Club of America. English cockers, bred for an affectionate temperament, are usually easy to train. The breed also does well in agility competition. Its primary purpose, like the American cocker, is household pet and best friend.
The muzzle of the American cocker is shorter than that of its English cousin, and its head and eyes tend to be rounder. The English dogs are larger than the Americans, both in height and weight. English cockers bear more of a resemblance to setters, and are often mistaken for English springer spaniels by those less knowledgeable about dog breeds. However, for all the differences between the two types, it may take a dog breed expert to determine which is which, when presented with a cocker spaniel of unknown lineage.
The classic American cocker spaniel is usually a buff color, a shade not present in the English version. American cockers also come in black and other solid colors, as well as white and another solid color. English cocker spaniels often have roan coats, or a mixture of white and other hair colors. Roaning is rare in the American cocker spaniel. English cocker spaniels come in a variety of coat colors, including solid black, golden, red or liver, with the same colors also present in the roans. The feet, muzzle, eyebrow, throat and rump of any English cockers may have tan points as well..