The aim of selectively breeding dogs is to enhance those physical or behavioral characteristics that are thought to be useful to their owners or handlers. Over the years years, dogs developed into groups based on their abilities and appearance, for example muscular heavy dogs were good guard dogs, and lean long legged animals were better at running down prey.
Geography initially played some role in the formation of these groups. The Molosser breed which originated in ancient Greece was used in the formation of guarding breeds such as the Rottweiler, which is thought to have originated during the Roman empire’s invasion of Germany. In the Far East, toy dogs were popular as pets and companions, and small breeds such as the Pekingese and the Tibetan Terrier were ideal for this purpose. In Scotland, there was a need for strong, tenacious little dogs to control vermin around farms and in mills, so the Scottish Terrier, Cairn Terrier and Skye Terrier evolved to fill this need. Their short stature, wiry coats and predatory nature made them ideal for going to ground and catching and killing rats and mice.
Until around the 19th century, breeding was focused on producing dogs that were good workers, rather than those that were nice looking. As breed standards were developed, then fanciers took more interest in breeding dogs that looked the part. This has resulted in individual dogs within a breed looking very similar, but perhaps not being able to do the work they were initially bred for.
Some dog clubs are trying to change this. One example is the American Border Collie Association. This group feels it is so important to maintain the Border Collie’s working ability that they won’t accept a dog for registration if it has been successful in the show ring such that they have earned the title “conformation champion”.
When you look closely at their history, there are very few true “pure bred” dogs. The Pekingese as a breed hasn’t changed much for thousands of years. Many dog breeds were developed by combining other breeds in the hope of producing a dog with the best characteristics of both parents. The Bullmastiff is a good example of this. This breed was produced by combining bloodlines of the English Mastiff and the Old English Bulldog to produce a strong and loyal watchdog for 19th century English gamekeepers. It was given purebred status by the American Kennel Club in 1924.
Similarly, the Cesky Terrier was produced in 1949 by crossing the Sealyham Terrier with the Scottish Terrier, to produce a type of dog that was better suited to hunting in Bohemian forestry. These charming little dogs were only recognized as a new breed in 2011.