Collie

Collies are a diverse group of herding dogs with a deep history. They originated in Scotland and Northern England. While many people think of a single breed, "collie" actually describes a type of dog. This type includes many different landraces and formal breeds. They are generally medium-sized dogs with light to medium bones. Most have pointed snouts and very high energy levels. Many varieties also feature a distinctive white patch over their shoulders.

The mechanics of the collie involve a powerful herding instinct. This instinct drives them to manage livestock like sheep and cattle. Working collies are built for extreme physical endurance. They can run all day over rough or steep ground without tiring. Their intelligence is a key part of how they work. They use keen observation to stay motivated for the job. In fact, the Border Collie is ranked first in Stanley Coren's book, *The Intelligence of Dogs*. This high intelligence makes them excellent for dog sports like flyball and agility.

Collie types are often divided by their intended purpose. Working strains are bred for stamina, agility, and intense focus. Some can even be single-minded or obsessive about their work. These dogs are used in specialized roles, such as mountain rescue. In Britain, Border Collies search large areas of hillsides and avalanche debris. On the other hand, show and pet types are bred differently. These include Rough Collies, Smooth Collies, and Shetland Sheepdogs. They are often selected for their appearance in conformation showing. They are known for being gentle, loyal, and compatible with children.

The history of the collie name is somewhat uncertain. It may come from the Scots word for "coal." It might also relate to the word "coolly," referring to black-faced sheep in Scotland. Some suggest the Gaelic word "collie" simply meant anything useful. This name reflects the dog's role as a vital tool for rural life. The popularity of these dogs grew through literature and film. In the 1920s and 1930s, Albert Payson Terhune wrote popular books about them. Later, the character Lassie became a global icon. Lassie was inspired by a real dog named Tootsie.

Collies display a wide variety of colors and patterns. Common base colors include black, red, and sable. They can also be black-and-tan or tricolor. Many possess a merle pattern, which creates patches of color. White markings are common on the chest, belly, and legs. The Bearded Collie is a notable example of variety. They have a shaggy coat and a beard on their chin. Interestingly, all Bearded Collies are born specific colors like black or brown. They may carry a fading gene that lightens their coat as they mature.

Different breeds have developed in various parts of the world. The Australian Kelpie was developed in Australia from Scottish and English collies. They often have erect ears and short hair. The Australian Shepherd also has collie ancestry, alongside Spanish and Basque dogs. These dogs are used as both guardians and drovers. They often show heterochromia, which means they have eyes of different colors. The English Shepherd was also developed in the United States from British farm collie types. These diverse lineages show how the collie type has adapted globally.

Despite their many strengths, some collie breeds face specific health challenges. Many, including the Rough Collie and Australian Shepherd, have a mutation in the MDR1 gene. This is also called ivermectin sensitivity. This mutation causes a lowered tolerance to over 100 different veterinary drugs. About 70% of collies are affected by this condition. They may also have fragile intestinal systems that require high-quality nutrition. Other serious issues include canine cyclic neutropenia, a stem cell disorder. This condition often affects puppies that appear to be blue merles. There is also a genetic eye anomaly caused by a mutation in the NHEJ1 gene.