For at least 10 thousand years , humans have been involved in dog breeding. Dogs were originally bred for their behaviours and abilities. In the last 200 years they have been primarily bred for size, coat and colour. Humans have perpetuated breed differences in behaviour. Specific breeds are associated with certain aspects of behaviour, and some types of dogs are more predisposed toward training than others.
The nordic or spitz group of dogs includes the Husky, Elkhound, Japanese Akita, and Chow Chow. These dogs have powerful shoulders and dense coats, which they shed abundantly. They have tremendous stamina and are quite independent and aloof.
Collies, shepherd dogs, and cattle dogs evolved to work on teams with shepherds and farmers. Originally bred for their stamina and to nip at the heels of livestock, they are loyal and energetic. They bark when they are excited and have a tendency to nip.
Mountain dogs such as the Bernese and Great Pyrenees were bred to guard the flocks of sheep in the absence of the shepherd. They are relaxed but independent canines, with a tendency to be overprotective. Breeds such as dobermans and boxers were bred for protection.
Greyhounds, Whippets, Deerhounds, Afghan Hounds and Salukis are all built for speed. Sometimes aloof and distant, sight hounds are not overwhelmingly demonstrative dogs.
Setters, Pointers, Spaniels, and especially retriever, were all bred to be cooperative and to respond to human commands. As a result, they are often particularily affectionate dogs.
Bloodhounds, Basset Hounds and Beagles were originally bred to follow a scent, work in packs, and howl signals to their masters. They communicate well with other dogs and are able to follow the weakest trails.
Originally developed to chase small game and vermin, most terriers are small, robust diggers with powerful barks. They rarely back down when challenged and are the breeds most likely to snap and nip.
Toy dogs such as Chihuahuas, Tibetan breed, small poodles and spaniels, bichons have always been bred for companionship. They thrive on affection and human contact.