A dog's coat is its fur. A dog can be double coated—that is, having both a soft undercoat and a coarser topcoat. Some dog breeds are single-coated—having only one type of coat or the other, more often only the topcoat. The state of the coat is considered an indication of the animal's breeding and health.
Newfoundland lying next to its combed-out seasonal undercoat.
Many dogs shed their undercoat each spring and regrow it again as colder weather comes in; this is also referred to as blowing the coat. Many domesticated breeds shed their coat twice a year. In some climates, the topcoat and undercoat might shed continuously in greater and smaller quantities all year.
Some dog coats are said to be more like human hair than like animal fur; for example, the Poodle's coat grows continuously, getting longer and longer, and requires frequent trimming.
Dogs' coats come in a tremendous variety of colours, patterns, textures, and lengths. The words used to describe colours, in particular, can vary from breed to breed, so a colour that is called red in one breed might be called brown in another breed. Some dog breeds have only one coat length or texture, other breeds may have long or short fur of various textures. Breeds bred strictly for their working ability tend to have more variations than breeds bred primarily for their appearance over a longer time. Some very old breeds have more limited coat colours. It has recently been discovered that all coat colours are variations of black or yellow.
Dogs diverged from a now-extinct Asian wolf between 12,000 and 15,000 years ago, according to recent DNA studies. In that time, the long nose and heavy grey-colored double coat of the wolf has changed into the wide variety of dog shapes and coats and colors seen today. The change was due at first to genetic changes that occurred as the original dogs learned to tolerate the presence of humans, as shown in the research on foxes by Dmitri Belyaev in his Farm-Fox Experiment. The research found that a genetic change to tameness brought along other unexpected changes as well; one notable change was in the coats, changed from a typical fox coat to a spotted coat resembling a dog's coat. As ancient dogs learned to live near humans and became less like wolves, their appearance changed as well, long before any selective breeding was done by people.[1]
Domestic dogs often display the remnants of counter-shading, a common natural camouflage pattern. The general theory of countershading is that an animal that is lit from above will appear lighter on its upper half and darker on its lower half where it will usually be in its own shade.[2][3]
Colour inheritance
A Stanford University School of Medicine study published in Science in October, 2007 found the genetics that explain coat colors in other mammals such as in horse coats and in cat coats, did not apply to dogs.[4] The project took samples from 38 different breeds to find the gene (a beta defensin gene) responsible for dog coat color. One version produces yellow dogs, and a mutation produces black. All dog coat colors are modifications of black or yellow.[5] For example, the white in white miniature schnauzers is a cream color, not albinism (a genotype of e/e at MC1R.)
Modern dog breeds exhibit a diverse array of fur coats, including dogs without fur, such as the Mexican Hairless Dog. Dog coats vary in texture, color, and markings, and a specialized vocabulary has evolved to describe each characteristic.[6]
Brown and its variants, including mahogany, midtone brown, gray-brown, blackish brown; the Chesapeake Bay Retriever, whose colour "must be as nearly that of its working surroundings as possible", also uses the terms sedge and deadgrass. (Weimaraners are often described as "steel-grey" but they are in fact light brown.
Red—reminiscent of reddish woods such as cherry or mahogany—and its variants, including chestnut, , tawny, orange, roan, rust, red-gold, reddish brown, bronze, cinnamon, tan, ruby; also includes liver, a reddish brown somewhat the colour of cinnamon or bronze; the breed often determines whether "liver", "chocolate", "brown", or "red" is used to describe the colour, as in a liverGerman Shorthaired Pointer or a chocolateLabrador Retriever.
Gold Rich reddish-yellow, as in a Golden Retriever, and its variants, including yellow-gold, lion-coloured, fawn, apricot, wheaten (pale yellow or fawn, like the colour of ripe wheat), tawny, straw, yellow-red, mustard, sandy, honey.
Yellow—yellowish-gold tan, as in a yellow Labrador Retriever—and its variants, including blond and lemon. Lemon is a very pale yellow or wheaten colour which is not present at birth (the puppies are born white) but gradually becomes apparent, usually during the first six months of life.
Cream: Sometimes it's hard to define the line between pale yellow and cream. Depending on the breed and individual, cream ranges from white through ivory and blond, often occurring with or beneath lemon, yellow, and sable.
Sable: Black-tipped hairs; the background colour can be gold to yellow, silver, gray, or tan. The darkness of the coat depends on how much of each hair is black versus the lighter colour.
Gray—sometimes also called blue—and its variants, including pale to dark gray, silver, pepper, grizzle, slate, blue-black gray, black and silver, steel, lavender, silver-fawn.
Black and tan, liver and tan: Coat has both colours but in clearly defined and separated areas, usually with the darker colour on most of the body and tan (reddish variants) underneath and in highlights such as the eyebrows.
Two-colour (also called bicolour, Irish spotting, or flashy) coats such as gold and white, liver and white, tan and white, black and white: Usually sharply contrasting colours, usually with the darker colour on most of the body and lighter colour underneath and in highlights such as the eyebrows, although sometimes one colour is in patches, ticks, or other types of markings. Some breeds have special names for the colour combinations; for example, Cavalier King Charles Spaniel uses Blenheim for reddish brown (chestnut) and white. Irish Spotted or flashy pattern is symmetrical and includes a white chest, white band around the neck, white belly, and white feet or "boots." This pattern is commonly seen in herding dogs, and Boxers, among others.
Tricolour: Three clearly defined colours, usually either black or red on the dog's upper parts, white underneath, with a tan border between and tan highlights; for example, the Smooth Collie or the Sheltie. Tricolour can also refer to a dog whose coat is patched, usually two colours (such as black and tan) on a white background.
Tuxedo: Solid (usually black) with a white patch (shirt front) on the chest and chin, and white on some or all of the feet (spats.) Common colouration in Labradormixes that may stem from the St. John's Water Dog ancestral breed.
Wolf, wolf-sable or wolf-grey: Possessing a colour and pattern similar to that of a wild wolf. The undercoat is light but the top-coat is dark. This is fairly common among spitz breeds.
Texture
Texture, like colour and pattern, might be called by different terms for different breeds, even when referring to the same quality of coat. Some terms used to describe dog coat texture are smooth, rough, curly, straight, broken, and silky.
Coat textures vary tremendously. Densely furred breeds such as most sled dogs and Spitz types can have up to 600 hairs per inch, while fine-haired breeds such as the Yorkshire Terrier can have as few as 100, and the "hairless" breeds such as the Mexican Hairless and the Peruvian Inca Orchid have none on parts of their bodies. The texture of the coat often depends on the distribution and the length of the two parts of a dog's coat, its thick, warm undercoat (or down) and its rougher, somewhat weather-resistant outer coat (topcoat, also referred to as guard hairs). Breeds with soft coats often have more or longer undercoat hairs than guard hairs; rough-textured coats often have more or longer guard hairs. Textures include:
Double-coated: Having a thick, warm, short undercoat (or down) that is usually dense enough to resist penetration by water and a stronger, rougher weather-resistant outer coat (topcoat), also referred to as guard hairs. Most other coat types are also double-coated.
Single-coated: Lacking an undercoat.
Smooth-coated: "Smooth" to the eye and touch.
Wire-haired: Also called broken-coated. The harsh outer guard hairs are prominent, providing excellent weather protection for hunting dogs such as the Border Terrier or Wirehaired Pointing Griffon.
The nature and quality of a purebred dog's coat is important to the dog fancy in the judging of the dog at conformation shows. The exact requirements are detailed in each breed's breed standard and do not generalise in any way, and the terminology may be very different even when referring to similar features. See individual breed articles for specific information.
Hypoallergenic coats
Some dog breeds have been promoted as hypoallergenic (which means less allergic, not free of allergens) because they shed very little or have the same pH as human hair. However, no canine is known to be completely nonallergenic. Often the problem is with the dog's saliva or dander, not the fur.[7] Although poodles and terriers (and mixes of poodles and terriers) are commonly represented as being hypoallergenic, the reaction that an individual person has to an individual dog may vary greatly. In treating dog related allergies, it has been found that "Factors related to individual dogs seem to influence the allergenicity more than breed..."[8]
Miscellaneous
Coat may also refer to a dog coat (also known as a dog rug); a garment made by humans to protect their pets from the elements.
Encyclopedia
top
