The American Cocker Spaniel is a medium sized dog of normal proportions, with medium long silky fur on the body and ears, hanging down on the legs and belly (feathering). The head has a rounded look and the ears hang down (drop ears). The tail is often docked, though is only required for show, and is recommended for American Cocker Spaniels who hunt. Coat colors are described extensively in the Standard. The English Cocker Spaniel has a more rectangular head, a shorter coat, and is larger.

American Cocker Spaniels have an ideal size of 14.2-15.4 inches (36-39 cm) at the withers for male dogs and 14.2-15.4 inches (34-37 cm) for females. The breed standard states that size over 15.5 inches for males and 14.5 inches for females is a disqualification at a breed show, in order to discourage the breeding of oversize dogs. Both sex weigh to approximately 11-13 kgs (24.3–28.6 lbs).

The dog is a domesticated form of the Gray Wolf. The term is used for both feral and pet varieties. The domestic dog has been one of the most widely kept working and companion animals in human history. Amongst canine enthusiasts, the word “dog” may also mean the male of a canine species, as opposed to the word “bitch” (the female of the species).

The dog quickly became ubiquitous across culture in all parts of the world, and was extremely valuable to early human settlements. For instance, it is believed that the successful emigration across the Bering Strait might not have been possible without sled dogs. Dogs perform many roles for people, such as hunting, herding, protection, companionship, and, more recently, assisting handicapped individuals. Currently, there are estimated to be 400 million dogs in the world.