The Collie is a distinctive type of herding dog, including many related landraces and formal breeds. It originates in Scotland and Northern England. It is a medium-sized, fairly lightly built dog with a pointed snout, and many types have a distinctive white pattern over the shoulders. Collies are very active and agile, and most types have a very strong herding instinct. The collie type has spread through many parts of the world (especially Australia and North America) and has diversified into many varieties, sometimes with mixture from other dog types. Some of the collie types have remained as working dogs, used for herding cattle, sheep and other livestock, while others are kept as pets, show dogs or for dog sports, in which they display great agility, stamina and trainability. While the AKC does have a breed they call "Collie", the truth in fact is that collie dogs are a distinctive type of herding dog including many related landraces and formal breeds. There are usually major distinctions between show dogs and those bred for herding trials or dog sports. They typically display great agility, stamina and trainability and more importantly sagacity.
Common use of the name "collie" in some areas is limited largely to certain breeds – such as to the Rough Collie in parts of the United States, or to the Border Collie in many rural parts of Great Britain. Many collie types do not actually include "collie" in their name.
The exact origin of the name "collie" is uncertain, it may derive from the Scots word for "coal." Alternatively it may come from the related word coolley, referring to the black-faced mountain sheep of Scotland. The collie name usually refers to dogs of Scottish origin which have spread into many other parts of the world, often being called sheepdog or shepherd dog elsewhere.
Collies are generally medium-sized dogs of about 22 to 32 kg (48 to 70 lb) and light to medium-boned. Cattle-herding types are more stocky. The fur may be short, flat, or long, and the tail may be smooth, feathered, or bushy. Collies can have both naturally long or naturally bobbed tails. Some breed clubs historically dock the tail. The tail can be carried low with an upward swirl or twist or high over the back. The tail never curls at the base or touches the back. Each breed can vary in colouration, with the usual base colours being black, black-and-tan, red, red-and-tan, or sable. They often have white along with the main colour, usually under the belly and chest, over the shoulders, and on parts of the face and legs, but sometimes leaving only the head coloured – or white may be absent or limited to the chest and toes (as in the Australian Kelpie). Merle coloration may also be present over any of the other colour combinations, even in landrace types. The most widespread patterns include sable, black-and-white, and tricolour (black-and-tan and white) also known as black sable.
Collies range in trainability from the "average" to very biddable. The Border Collie is also the breed most in need of a job, while other collie breeds fit well into an active family lifestyle.
A working member of the collie breed, such as the Border Collie, is an extremely energetic and agile dog with great stamina. When in fit working condition they are able to run all day without tiring, even over very rough or steep ground. Working collies display a keen intelligence for the job at hand and are instinctively highly motivated. They are often intensely loyal. Dogs of collie type or derivation occupy four of the first sixteen ranks in Stanley Coren's The Intelligence of Dogs, with the Border Collie being first. These characteristics generally make working strains suitable for agility; in addition to herding work they are well suited to active sports such as sheepdog trials, flyball, disc dog and dog agility. Working strains have strong herding instincts, and some individuals can be single-minded to the point of obsessiveness. Collies can compete in herding events.
Show and pet types
Certain types of collie (for example Rough Collies, Smooth Collies, Shetland Sheepdogs and some strains of Border Collie and other breeds) have been bred for many generations as pets and for the sport of conformation showing, not as herding dogs. All collie dog breeds have proved to be highly trainable, gentle, loyal, intelligent, and well suited as pets. Their gentleness and devotion also make them quite compatible with children. They are often more suitable as watchdogs than as guard dogs, though the individual personalities of these dogs vary.
The temperament of these breeds has been featured in literature, film, and popular television programs. The novels of Albert Payson Terhune, which were very popular in the United States during the 1920s and 1930s, celebrated the temperament and companionship of his early AKC collies. More famously, the temperament and intelligence of the Rough Collie were exaggerated to mythic proportions in the character Lassie, which has been the subject of many films, books, and television shows from 1938 to the present.
The Lassie character was featured in a book titled Lassie Come Home by Eric P. Knight. Knight's collie "Tootsie" was the inspiration for the book, which was a collection of stories based on her and other collie legends he collected from talking to friends and neighbors. One such story was most likely the documented tale of "Silverton Bobbie", the Oregon collie who crossed the US to get to his owners. While the dogs who played Lassie on-screen were from AKC lines, the actual Tootsie looked nothing like them, although she did come from a collie breeder.
Collies may have a genetic disease, canine cyclic neutropenia, or Grey Collie Syndrome. This is a stem cell disorder. Puppies with this disorder are quite often mistaken for healthy Blue Merles, even though their colour is a silver grey. Affected puppies rarely live more than 6 months. For a puppy to be affected, both the sire and the dam have to be carriers of the disorder.
Collie types and breeds
Herding dogs of collie type have long been widespread in Britain, and these can be regarded as a landrace from which a number of other landraces, types, and formal breeds have been derived, both in Britain and elsewhere. Many of them are working herding dogs, but some have been bred for conformation showing and as pets, sometimes losing their working instincts in the course of selection for appearance or for a more subdued temperament.
Herding types tend to be more variable in appearance than conformation and pet types, as they are bred primarily for their working ability, and appearance is thus of lower importance.
Dogs of collie type or ancestry include:
Australian Cattle Dog. Dog used in Australia for herding cattle. Dogs of this type are also known as Queensland Heeler, Blue Heeler and Red Heeler. Powerful build, erect ears, short-haired, mottled grey or red with solid colour patches on head, and no white.
Australian Collie or "Bordaussie". Not actually a breed, but a popular cross between two other collie types, Australian Shepherd and Border Collie. Appearance intermediate between parents.
Australian Kelpie. Developed in Australia from collies originally brought from Scotland and northern England. Erect ears, short-haired, usually black, black-and-tan or red-and-tan, with white limited to chest and toes.
Australian Stumpy Tail Cattle Dog. Dog with stumpy tail used in Australia for herding cattle. Erect ears, lightly built, short fur, mottled grey or red with no white, and either no tail or a very short tail.
Bearded Collie. Now largely a pet and show breed, but still of collie type, and some are used as working dogs. Floppy ears, long silky fur (including on face and legs), black, grey or fawn, and white over shoulders.
Blue Lacy. Grey or red all over, short hair, floppy ears. Derived partly from the English Shepherd, with other non-collie breeds.
Border Collie. The most well known breed for herding sheep throughout the world. Originally developed in Scotland and Northern England. Not always suitable for herding cattle. Ears semi-erect or floppy, fur silky or fairly long, but short on face and legs; red, black, black-and-tan or merle, all usually with white over shoulders, alternatively mostly white with coloured patches on head.
Cumberland Sheepdog. An extinct breed similar to the Border Collie and possibly absorbed into that breed. An ancestor of the Australian Shepherd. Erect or semi-erect ears, dense fur, black with white only on face and chest.
Farm Collie. Landrace herding dog found on many livestock farms in Britain, in the US (derived from British dogs), and perhaps elsewhere. In Britain, often simply called "farm dog", or, loosely, "Border Collie". Very variable in size and appearance.
German Coolie, Koolie or Collie. Developed in Australia, probably from British collies, but may have included dogs from Germany and Spain. Erect ears, short fur, black, red, black-and-tan or merle, often with some white on neck or over shoulders. (Note: the name "German Collie" is also applied to a cross between a German Shepherd and a Border Collie.)
Huntaway. Developed in New Zealand from a mixture of breeds, probably including some collie – but it is not of collie type. Larger and more heavily built than most collies, floppy ears, most commonly black-and-tan with little white.
Lurcher. Not a breed, but a cross of collie (or other herding dog or terrier) with Greyhound or other sight hound. Traditionally bred for poaching, with the speed of a sight hound but more obedient and less conspicuous. Variable in appearance, but with greyhound build: floppy ears, tall, slender, with small head, deep chest and "herring gut"; smooth, silky or rough coat, often brindled.
McNab Shepherd. Developed in the US from British collies. Variable in size, erect or semi-erect ears, short fur, black or red usually with some white on face and chest.
New Zealand Heading or Eye Dog. Developed in New Zealand from Border Collie heritage, and used to bring sheep towards the shepherd especially with strong eye contact and no barking.
Old English Sheepdog. Derived from "Shags", hairy herding dogs, themselves derived from "Beards", the ancestors of the Bearded Collie. Modern dogs larger than most collies, no tail, floppy ears, long silky hair (including on face), usually grey and white. Not to be confused with the English Shepherd.
Scotch Collie, separated into two varieties or breeds: Rough Collie and Smooth Collie. They are still used for herding as well as for showing. They were developed in the highlands of Scotland which is why they needed a profuse coat and  They rather a different type to other collies with a long narrow face, tall, profuse coar and semi-erect ears. There are four recognised colors: sable, tri-color, blue merle and color headed white. Non recognized colors are: bi-black, sable merle, harlequin, red merle, red tricolor and black and tan.  Both the rough and smooth collies are double-coated with Smooths having a shorter or "smooth" outer coat. There are three different coat types of Rough Collies: Brandwyn (fluffy coats), Parader (flat long coats) and the working type (medium length coats).
Shetland Sheepdog. A small show and pet breed developed in England partly from herding dogs originating in Shetland. The Shetland dogs were originally working herding dogs, not collies but of Spitz type (similar to the Icelandic Sheepdog). However in the development of the modern breed these Spitz-type dogs were heavily mixed with the Rough Collie and toy breeds, and are now similar in appearance to a miniature Rough Collie. Very small, nearly erect ears, long silky fur on body, most commonly sable or merle, with white over shoulders.
Smithfield. Originally a British type, now extinct: a large, strong collie, white or black-and-white, floppy-eared, used for droving cattle in the south-east of England, especially the Smithfield Market in London. Occasionally the name is used for modern dogs of a somewhat similar type in Australia. The name "Smithfield" is used to describe the shaggy Tasmanian farm dog of Bearded Collie type; and is also applied to the Australian Stumpy Tail Cattle Dog and may have contributed to the Australian Koolie.
Welsh Sheepdog. Landrace herding dog from Wales. Erect or semi-erect ears, short or silky fur, red, black, black-and-tan or merle, all usually with white over shoulders.