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Dog coat

The coat of the domestic dog refers to the hair that covers its body. Dogs demonstrate a wide range of coat colors, patterns, textures, and lengths.

Coat variation of the dog

As with other mammals, a dog's fur has many uses, including thermoregulation and protection from cuts or scratches; furthermore, a dog's coat plays an important role in the showing of purebred dogs. Breed standards often include a detailed description of the nature and attributes of that breed's ideal coat.

A dog's coat is composed of two layers: a top coat of stiff guard hairs that help repel water and shield from dirt, and an undercoat of soft down hairs, to serve as insulation.[1] Dogs with both under coat and top coat are said to have a double coat. Dogs with a single coat have a coat composed solely of guard hairs, with little or no downy undercoat.

The terms fur and hair are often used interchangeably when describing a dog's coat, however in general, a double coat, like that of the Newfoundland and most livestock guardian dogs, is referred to as a fur coat, while a single coat, like that of the Poodle, is referred to as a hair coat.

Genetics edit

 
A Labrador exhibiting a yellow coat colour

Domestic dogs exhibit diverse coat colours and patterns. In many mammals, different colour patterns are the result of the regulation of the Agouti gene, which can cause hair follicles to switch from making black or brown pigments to yellow or nearly white pigments. The most common coat pattern found in modern wolves is agouti, in which the upperside of the body has banded hairs and the underside exhibits lighter shading. The colour yellow is dominant to the colour black and is found in dogs across much of the world and the dingo in Australia.[2]

In 2021, a study of whole genome sequences taken from dogs and wolves focused on the genetic relationships between them based on coat colour. The study found that most dog colour haplotypes were similar to most wolf haplotypes, however dominant yellow in dogs was closely related to white in arctic wolves from North America. This result suggests a common origin for dominant yellow in dogs and white in wolves but without recent gene flow, because this clade was found to be genetically basal to the golden jackal and genetically distinct from all other canids. The most recent common ancestor of the golden jackal and the wolf lineage dates back to 2 million years ago. The study proposes that 35,000 years ago there was genetic introgression into the Late Pleistocene grey wolf from a ghost population of an extinct canid which had diverged from the grey wolf lineage over 2 million years ago. This colour diversity could be found 35,000 years ago in wolves and 9,500 years ago in dogs. A closely related haplotype exists among those wolves of Tibet which possess yellow shading in their coats. The study explains the colour relationships between modern dogs and wolves, white wolves from North America, yellow dogs, and yellowish wolves from Tibet. The study concludes that during the Late Pleistocene, natural selection laid the genetic foundation for modern coat colour diversity in dogs and wolves.[2]

During evolution of the dog from their wolf ancestors, coat colors in dogs were probably the inadvertent outcome of some other selective process, and were not likely initially selected for intentionally by humans.[3] Research has found that tameness brings associated physical changes, including coat colouring and patterning.[4]

Domestic dogs often display the remnants of countershading, a common natural camouflage pattern. The basic principle of countershading is when the animal is lit from above, shadows will be cast on the ventral side of the body. These shadows could provide a predator or prey with visual cues relating to the movement of the animal. By being lighter colored on the ventral side of the body, an animal can counteract this, and thereby fool the predator or prey. An alternative explanation is that the dorsal and ventral sides of an animal experience different selection pressures (from the need to blend into different backgrounds when viewed from above and below) resulting in differing coloration.[5]

Nomenclature of colours and patterns edit

Colors edit

The same colour may be referred to differently in different breeds. Likewise, a same term may mean different colourations in different breeds.

Brown, chocolate, liver edit

Brown, chocolate and liver are the most common terms used to refer to the bb-dilution of black pigment to a dark brown. Depending on breed and exact shade, terms such as mahogany, midtone brown, grey-brown, blackish brown are used. Sedge and deadgrass are used to describe the desired Chesapeake Bay Retriever color that resembles "that of its working surroundings" as closely as possible.

Red edit

Red refers to reddish shades of orange, brown, and tan. Terms used include orange, red-gold, cinnamon, tan, and ruby. Genetically a dog called red is usually a clear sable (with little to no eumelanin tipping on hairs) or a ruddy recessive yellow.

In some breeds, "red" refers to what would usually be called brown, chocolate, or liver. A "red merle" is always a liver-based merle. In Australian Cattle Dogs, "blue" stands for a densely ticked liver-based colouration with an overall red-grey appearance.

Gold and yellow edit

Gold refers specifically to a rich reddish-yellow and its variants, whereas yellow can refer to any shade of yellow and tan. Terms used include yellow-gold, lion-colored, fawn, apricot, wheaten, tawny, straw, yellow-red, mustard, sandy, honey, blond, and lemon. Dogs called golden or yellow tend to be recessive yellow, but can also be sable.

Cream edit

Cream refers to a pale yellowish or tannish colour which can be almost white.

Fawn edit

Fawn typically refers to a yellow, tan, light brown, or cream dog that has a dark melanistic mask.

With Weimaraners, fawn refers to their typical brownish grey colouration that with other breeds is usually called lilac.

Black edit

Black is a pure black that can get grizzled as the dog ages, or have a tendency to gain a brownish cast when exposed to the elements.

Blue edit

Blue is a cool-toned, metallic grey. It typically means a d/d dilution of black pigment, a grey colouration that is grey from birth, but has a wide range of breed-specific meanings.

In Kerry Blue Terriers, Poodles, and Bearded Collies, "blue" refers to colouration that is black at birth and progressively greys out as the dog matures. In Australian Shepherds, Rough Collies, and Shetland Sheepdogs, blue means a blue (black-based) merle. In Australian Silky Terriers, blue means a saddle-type black and tan pattern, where the black parts of the coat progressively fade to a steel grey as the dog matures and in Australian Cattle Dogs, blue stands for a densely ticked black-based colouration with an overall blue-grey appearance.

Grey edit

Grey simply means a grey colouration of any shade. It can be used as an alternative synonym of blue, but tends to mean some other type of grey than the d/d dilution of black. Synonyms include silver, pepper, grizzle, slate, blue-black grey, black and silver, steel. Greys of a dusty or brownish cast are often lilac, a d/d dilution of liver, and this colouration does not have much of a commonly recognised name. Across various breeds, it is called lavender, silver-fawn, isabella, fawn, café au lait or silver beige.

In Poodles, a blue is a very slowly fading, very dark steel grey, whereas a silver is a quicker to clear, much lighter grey that can range from a pale platinum to a steel grey. Both are black at birth with minimal markings to indicate future change. Similarly, café au lait is a slower and darker and silver beige a quicker and lighter progressively greying brown, i.e. liver.

White edit

White: Such a light cream that it is seen and described as pure white, making them distinct from albino dogs. A white dog, as opposed to an albino one, has dark pigment around the eye rims and nose, often coupled with dark-colored eyes. There is often some coat identifiable as cream between the dog's shoulder blades. Extreme piebald dogs can also appear all white, but are caused by a separate factor.

Patterns edit

The same pattern may be referred to differently in different breeds.

 
Black and Tan Dachshund
 
Black and tan Miniature Pinscher
Black and tan, liver and tan, blue and tan: Coat has both colors but in clearly defined and separated areas, usually with the darker color on most of the body and tan (reddish variants) underneath and in highlights such as the eyebrows. Black and brindle and liver and brindle, in which the same pattern is evident with brindling in place of tan, are also possible, but less common.
 
Black and white Border Collie
 
Blenheim (Red-brown and white) Cavalier King Charles Spaniel
Piebald or pied (also called bicolor, tricolor, Irish spotted, Flashy, Patched, Tuxedo): any color or pattern coupled with white spotting. This can range anywhere from white toes and tail tip to a mostly white dog with color around the base of the ears and tail. Some breeds have special names for the color 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. The piebald gene is responsible for this pattern.
 
Extreme piebald Borzoi with small colored patches
 
Piebald white Dogo Argentino
Extreme piebald or piebald white: an extensive piebald pattern that renders the dog mostly or all white with pink skin. Usually some pigmented specks remain. Governed by the piebald gene.
 
Tricolor

Basset Hound

 
Tricolor Beagle
Tricolor: Three clearly defined colors, usually either black, liver, or blue on the dog's upper parts, white underneath, with a tan border between and tan highlights; for example, the Smooth Collie, the Rough Collie, the Papillon, or the Sheltie. Tricolor can also refer to a dog whose coat is patched, usually two colors (such as black and tan) on a white background.
 
Blue merle tricolor Shetland Sheepdog
 
Red merle Catahoula Leopard Dogs
Merle: Marbled coat with darker patches and spots of the specified color. Merle is referred to as "Dapple" in Dachshunds.
 
Tuxedo Lab mix.
 
Tuxedo Collie mix
Tuxedo: Solid (often black) with a white patch (shirt front) on the chest and chin, and white on some or all of the feet (spats.) The tuxedo pattern is common in dogs that carry only one piebald gene (a heterozygous carrier).
 
Harlequin Great Dane
 
Harlequin Great Dane
Harlequin: "ripped" splotches of black on white. The Great Dane is the only breed with this pattern. The term harlequin is also sometimes used to describe a piebald spotting pattern, such as parti-colored poodles.
 
Spotted Dalmatian
 
Spotted mutt in Sinamaica, Venezuela
Spotted Coin-sized pigmented spots on a white background. The spotting on Dalmatians is unique as it involves mutations in at least three different spotting genes.[6]
 
Red-speckled Australian Cattle Dog
 
Liver-ticked German Shorthaired Pointer
Flecked, ticked, speckled: also called belton in English Setters
 
Orange belton (orange and white speckled) English Setter
 
Blue speckled Australian Cattle Dog
 
Brown brindle and white Boxer
 
Very sparsely brindled Great Dane
Brindle: A mixture of black/liver/blue/lilac and red/yellow/cream arranged in a vertical "tiger stripe" pattern.
 
Airedale Terrier with large black saddle
 
Norwegian Dunker with merle-affected black saddle
Saddle or blanket: A different color, usually darker, over the centre of the back.
 
Dark orange sable Pomeranian
 
Sable Pembroke Welsh Corgi
Sable: Black-tipped hairs overlaid onto a different coloured, lighter background, including grey, silver and gold.[7]
 
Hairless Chinese Crested Dog
 
Xoloitzcuintle
Hairless: Some dogs are born without a fur coat.


Length and texture edit

 
 Bearded Collie (top, with facial furnishings) vs border collie (bottom, no furnishings)

Dogs demonstrate an enormous diversity in coat length and texture, from the very short and smooth coat seen in the vizslas, to the wiry coat of a Scottish Terrier and the corded coat of the Puli and the Komondor.

Generally, coats vary along three categories: length (long vs. short), texture (curly vs. straight), and coarseness (wire-haired vs. non-wire). These three categories all interact with one another; thus, one can see a short, curly, and wired coat in the Wirehaired Pointing Griffon, and a long, straight, and non-wired coat in the Pomeranian.[8]

Additionally, breeds show variation in patterns of growth - that is to say, parts of the dog's body where the coat may be longer or shorter. The same gene that controls wiriness of hair also causes furnishings to be present (e.g. beard, moustache, eyebrows) [8] - compare the bearded collie, furnishings present, to the border collie, which lacks furnishings. Some breeds show feathering: fringes of longer hair on the ears, belly, tail, and back of the legs (e.g., Saluki and any of the setters).

Dogs also vary in the thickness of the undercoat. Some dogs have only a single (rather than a double) coat, or a very reduced undercoat (e.g. the Vizsla), which results in a thinner coat. Certain breeds, especially spitz-type breeds, tend to have a thicker undercoat, which helps retain heat in cold and wet weather.

Furthermore, complete hairlessness on parts of the body is present in breeds such as the Chinese Crested or the Xoloitzcuintli.


Shedding edit

 
A slicker brush with wire bristles, used for removing loose hair from the coat.

Shedding of hair can occur continuously, but in many breeds is strongly influenced by hormones. Seasonal shedders shed most in spring and fall, following an increase or decrease in day length, and least in summer and winter, in response to constant day length. Cold temperatures stimulate hair growth, so that the heaviest shedding is in spring on dogs living in cold climates. Artificial lighting can alter the seasonal shedding pattern of dogs who live indoors. Other hormonal influences include dietary factors, reproductive hormones in intact dogs, and various medical conditions and disorders. Shedding that is done in a short period of time is known as "blowing the coat" or "blowing coat".[9][10] Among the other coat types, dogs with fine silky coats (e.g., spaniels) are generally moderate shedders, those with an intermediate coat texture (e.g., mountain dogs) are generally heavy shedders, and those with thick stand-offish coats (e.g., spitzes) are generally very heavy shedders.

 
The Portuguese Water Dog is an example of a breed with single, low-shedding coat.

"Non-shedding" dogs have greatly-reduced shedding due to alterations to the hair follicle growth cycle:

  • homozygosity for the furnishings (wire) allele - Most breeds with facial furnishings (including ones whose faces are usually shaved removing the furnishings) are low-shedding, but they must be homozygous, so dogs of mixed wire/non-wire parentage (e.g., terrier crosses or breeds with wire and non-wire varieties) can be heavy shedders. There are a few furnished breeds that shed more (e.g., Old English Sheepdog, Bearded Collie, Briard, Otterhound);
  • at least one copy of the single-coat (non-shedding) allele - Most dogs with a smooth coat are low shedding, as well as the fringed or flat coat. There are breeds with a very short coat that shed more (e.g., Basset Hound, English Bulldog, Pug, Toy Fox Terrier, Dalmatian, Vizsla, German Shorthaired Pointer);
  • single coat (no undercoat) plus furnishings (homozygous) - These breeds shed the least (e.g., Poodle, Soft-coated Wheaten Terrier).

Hypoallergenic coat edit

"[D]ogs are a relevant source of allergens, but diagnosing dog-related allergies may present difficulties .."[11] Some dog breeds have been promoted as hypoallergenic (which means less allergic, not free of allergens) because they shed very little. However, no canine is known to be completely nonallergenic. Often the problem is with the dog's saliva or dander, not the fur.[12] Although breeds such as poodles, bedlingtons, bichons, yorkies, and wire-haired terriers are commonly represented as being hypoallergenic due to reduced shedding, the reaction that an individual person has to an individual dog may vary greatly. In a report, describing dog allergen extracts of dog hair, belonging to patients' dogs or from dogs of the same breed, with low molecular mass that are absent in extracts of commercial allergen test kits, it has been found that "[f]actors related to individual dogs seem to influence the allergenicity more than breed or gender."[11]

Show coats edit

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.

Nutritional impacts on coat edit

A dog's coat is an outward indicator of internal well-being.[13] For this reason, coat health is an important aspect of pet care to many dog owners.[13] Dog coats can be impacted by nutritional components from the diet.[14] Below is a table that summarizes the effects of several nutrients (minerals, vitamins) on the domestic canine coat, based on current evidence:

Nutrient Role Impacts when deficient Benefits
Zinc Gives strength to collagen[15] Dry and brittle coat[15] Contributes to coat growth and prevents brittle and dry coat[15]
Copper Involved in keratinization[16] Brittle fur, hypo-pigmentation, discoloration[16] Improved color and keratinization[16]
Selenium Cell growth; antioxidant[17][18] Sparse coat growth[17] Coat growth promotion[18]
Vitamin A Proliferation of keratinocytes[19] Rough coat[19] Proliferation of keratinocytes; hair follicle growth[20][19]
Biotin Saturation of Coat[21] Alopecia and achromotrichia beginning at the root of the coat[21] Contributes to coat shine, thickness/distribution of hair follicles[21]

Trace minerals edit

Zinc edit

Zinc contributes to hair growth and can prevent hair from becoming dry and brittle.[15] In addition to, zinc when supplemented in combination with linoleic acids has been found to improve the coat of canines by reducing water loss in the trans-epidermal layer of the skin.[22] Dogs can obtain zinc in their diet, through the addition of various ingredients, including; red meats, whole grains, poultry by-product meals, and fish meals.

Copper edit

Copper is a trace mineral that is required in the diet of canines at 7.3 mg/kg.[23] Copper is involved in multiple enzymatic pathways. In dogs, a lack of copper in the diet, leading to a copper deficiency, results in incomplete keratinization.[16] This leads to a dry coat, hypo-pigmentation, and discoloration of the coat.[16]

Selenium edit

Selenium is another one of the many trace minerals essential for a dog's diet. Selenium is typically required in lower levels in comparison to other minerals. It is involved in the prevention of oxidative damage as well as the production of anti-oxidants.[17] Selenium aids in the promotion of coat growth.[24] Lack of selenium in the diet of a dog can contribute to the occurrence of sparse coat growth.[25] Dogs can obtain selenium in their diet through the addition of various ingredients including; tuna fish, halibut, sardines, beef, chicken, and egg.

Vitamins edit

Vitamin A edit

Vitamin A deficiency can lead to rough coat, scaling of skin, and other dermatitis issues like alopecia.[19] It is also essential for cells to properly proliferate keratinocytes,[19] which are epithelial cells that produce keratin on the outermost layer of the skin for the cortisol cells of the hair follicle.[20] A deficiency in vitamin A can cause the common symptoms of dermatitis (dry, scaling skin and dull coat).[26]

Vitamin B7 (Biotin) edit

Vitamin B7, also known as biotin, is a water-soluble nutrient that is known to play a role associated with the maintenance and development of hair starting from the follicle. Although it has not been clinically shown to improve hair growth with supplementation alone, it has been shown to reverse deficiency in dogs born deficient.[27]

Symptoms of biotin deficiency include alopecia and achromotrichia. A clinical study of biotin showed the importance of biotin in coat pigmentation. There different stages of hair development, as shown in clinical studies using mice.[21] Each stage of hair development has a different sensitivity to biotin present in the body. For example, the shaft development is not greatly affected by biotin access.[21] During the last stage, the amount of biotin available for use by the body will alter the success of that development greatly.[21] Throughout the hair development, most stages of growth are completed, but it was found that in the last stage, where biotin levels were insufficient, there was an incorrect keratinization of the root of the hair, causing the hair to fall out of the body.[21]

The supplementation of biotin cannot reverse affects caused by deficiency, but as soon as supplementation is given and biotin levels are restored to adequacy, the body begins to produce the usual hair growth and color it would before the deficiency took place.[21]

Essential fatty acids edit

Polyunsaturated fatty acids found in the diet play a critical role in the maintenance of a healthy coat in dogs, and have even been shown to improve coat condition when supplemented in the diet.[14] Furthermore, diets lacking essential fatty acids in their diet will manifest as unkept, matted coat.[13] Omega fatty acids 3 and 6 are highly unsaturated fatty acids, making them especially metabolically active.[28]

The proper combination of these omega fatty acids is crucial to achieve optimal benefits. Proper omega 6:3 ratios have been shown to diminish allergy triggered immune responses, thus improving overall coat condition.[29] The National Research Council (NRC) recommends a 2.6:1 to 26:1 omega 6:3 ratio for adult dog maintenance diets.[30] The proper ratio of these fatty acids is crucial because each has an opposing role in inflammation within the body and both compete for the same enzymatic pathway.[13] Dogs, like many mammals, lack the desaturase enzymes capable of interconverting omega 3 and 6 fatty acids.[28] Therefore, the amount of inflammation in the body is dependent on the ratio between omega 3 and 6 fatty acids. Too little inflammation suppresses the immune system and the body's ability to heal, however excessive inflammation can irritate the skin and reduce the coat's overall appearance.[13]

Aside from omega fatty acids, lipid content in the canine diet is an important aspect of coat health.[13] The fat soluble vitamins (A, D, E and K) require lipids present in the diet for absorption, transport and deposition in canine adipose tissue.[31] The specific role of vitamins A and E for coat health are explored elsewhere in this article, as they pertain to immune function.[31] Another pet food regulating body, the Association of American Feed Control Officials (AAFCO), recommends that Vitamin E supplementation increase as polyunsaturated fatty acids are added to diet in order to counteract lipid oxidation and maintain the potency.[23] In addition, high fat diets in dogs were shown to dramatically improve coat sheen and appearance.[13] It is thought excess cholesterol esters are incorporated into the hair follicle, leading to the improved coat appearance.[13] The same study, by Kirby, Hester and Bauer (2007), stated the optimal approach to an improved coat in dogs is a combination of increased dietary fat and the proper amount of polyunsaturated fatty acids.[13]

Omega 3 (linolenic acid) edit

Omega 3 fatty acid, also known as linolenic acid, is an anti-inflammatory compound.[29] Linolenic acid is found in the oil from flaxseeds, soybean and canola.[29] Some better known examples of linolenic acid are the metabolic derivatives eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA). EPA inhibits the enzyme delta-5-desaturase, which prevents the synthesis of arachidonic acid which is an inflammatory omega 6.[32] DHA acts even earlier in omega 6 metabolism, by inhibiting delta-6-desaturase.[32] The anti-inflammatory properties of omega 3s stem from their ability to inhibit the inflammatory action of omega 6 fatty acids. A functional minimum has not been set forth by AAFCO, as one has yet to be determined.[23] A reduction in inflammation of somatic tissues, skin especially, supports coat health.[13]

Omega 6 (linoleic acid) edit

Omega 6 fatty acid, also known as linoleic acid, is found in poultry fat and the oil from safflower, sunflower, corn and flaxseed.[29] Arachidonic acid is a well known metabolic derivative of linoleic acid, found only in animal sources.[29] As mentioned above, arachindonic acid is a pro-inflammatory compound.[32] It is critical to note once again that canines are unable to interconvert between omega fatty acids and over supplying linoleic acid promotes excessive inflammation in the body, which can potentially reverse the coat benefits seen by supplying omega fatty acids in the diet. In contrast, linoleic acid is also required for epidermal lipid function and water retention, which benefits coat shine.[22][29] Having linoleic acid present in the diet has demonstrated a positive effect on skin, and thus by extension, coat.[13]

See also edit

References edit

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  2. ^ a b Bannasch, Danika L.; et al. (2021). "Dog colour patterns explained by modular promoters of ancient canid origin". Nature Ecology & Evolution. 5 (10): 1415–1423. doi:10.1038/s41559-021-01524-x. PMC 8484016. PMID 34385618.
  3. ^ James Serpell, ed. (1995). The Domestic Dog: Its Evolution, Behaviour and Interactions with People. Cambridge, United Kingdom: Cambridge University Press. p. 284. ISBN 978-0-521-42537-7.
  4. ^ Lyudmila N. Trut (March–April 1999). "Early Canid Domestication: The Farm-Fox Experiment". American Scientist. 87 (2): 160–169. Bibcode:1999AmSci..87.....T. doi:10.1511/1999.2.160.
  5. ^ Graeme D. Ruxton; Michael P. Speed; David J. Kelly (September 2004). "What, if anything, is the adaptive function of countershading?". Animal Behaviour. 68 (3): 445–451. doi:10.1016/j.anbehav.2003.12.009. S2CID 43106264.
  6. ^ Edward J. Cargill1, Thomas R. Famula, Robert D. Schnabel, George M. Strain & Keith E. Murphy (July 2005). The color of a Dalmatian's spots: Linkage evidence to support the TYRP1 gene. Vol. 1. p. 1. doi:10.1186/1746-6148-1-1. ISBN 978-1-74661-481-2. PMC 1192828. PMID 16045797. {{cite book}}: |journal= ignored (help)CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)
  7. ^ Cunliffe, Juliette (2004). "Coat Types, Colors and Markings". The Encyclopedia of Dog Breeds. Paragon Publishing. pp. 20–23 and various. ISBN 978-0-7525-8276-4.
  8. ^ a b Elaine Cadieu; Edouard Neff; Mark Quignon; Pascale Walsh; Kari Chase; Kevin Parker; Heidi Vonholdt; Bridgett Rhue; Alison Boyko; Adam Byers; Alexandra Wong; Aaron Mosher; Dana Elkahloun; Abdel Spady; Tyrone André; Catherine Lark; K Gordon Cargill; Michelle Bustamante; Carlos Wayne; Robert Ostrander. Coat variation in the domestic dog is governed by variants in three genes. OCLC 799147453.
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  15. ^ a b c d Goldberg, L.; Lenzy, Y. (2010). "Nutrition and hair". Clinics in Dermatology. 28 (4): 412–419. doi:10.1016/j.clindermatol.2010.03.038. PMID 20620758.
  16. ^ a b c d e Tewari, Singh, Gautam, Dwivedi (December 2013). "Nutritional dermatosis - a review". Intas Polivet. 14: 199–202 – via GALE.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  17. ^ a b c Guo, E.; Katta, R. (2017). "Diet and hair loss: effects of nutrient deficiency and supplement use". Dermatol Pract Concept. 7 (1): 1–10. doi:10.5826/dpc.0701a01. PMC 5315033. PMID 28243487.
  18. ^ a b Kapun, A. Plevnik; Salobir, J.; Levart, A.; Kalcher, G. Tavčar; Svete, A. Nemec; Kotnik, T. (2014-12-06). "Vitamin E supplementation in canine atopic dermatitis: improvement of clinical signs and effects on oxidative stress markers". Veterinary Record. 175 (22): 560. doi:10.1136/vr.102547. ISSN 0042-4900. PMID 25205675. S2CID 23201891.
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  23. ^ a b c "The Association of American Feed Control Officials > Publications". www.aafco.org. Retrieved 2017-11-28.
  24. ^ Hatfield, D.; Tsuji, P.; Carlson, B.; Gladyshev, V. (2014). "Selenium and selenocysteine: roles in cancer, health and development". Trends Biochem Sci. 39 (3): 112–120. doi:10.1016/j.tibs.2013.12.007. PMC 3943681. PMID 24485058.
  25. ^ Sengupta, A.; Lichti, U.; Carlson, B.; Ryscavage, A.; Gladyshev, V.; Yuspa, S.; Hatfield, D. (2010). "Selenoproteins are essential for proper keratinocyte function and skin development". PLOS ONE. 5 (8): e12249. Bibcode:2010PLoSO...512249S. doi:10.1371/journal.pone.0012249. PMC 2923614. PMID 20805887.
  26. ^ Beigh, S.A; Soodan, J.S; Bhat, A.M; Singh, V; Tantary, H (2013). "Clinical diagnosis and management of vitamin--a responsive canine dermatosis". Intas Polivet. 14 (2): 207–210.
  27. ^ Zempleni, Janos; Hassan, Yousef I; Wijeratne, Subhashinee SK (2008-11-01). "Biotin and biotinidase deficiency". Expert Review of Endocrinology & Metabolism. 3 (6): 715–724. doi:10.1586/17446651.3.6.715. ISSN 1744-6651. PMC 2726758. PMID 19727438.
  28. ^ a b Murru, Elisabetta; Banni, Sebastiano; Carta, Gianfranca (2013). "Nutritional Properties of Dietary Omega-3-Enriched Phospholipids". BioMed Research International. 2013: 965417. doi:10.1155/2013/965417. ISSN 2314-6133. PMC 3747496. PMID 23984423.
  29. ^ a b c d e f Canine and feline nutrition : a resource for companion animal professionals. Case, Linda P. (3rd ed.). Maryland Heights, Mo.: Mosby. 2011. ISBN 9780323066198. OCLC 664112342.{{cite book}}: CS1 maint: others (link)
  30. ^ Nutrition., National Research Council (U.S.). Ad Hoc Committee on Dog and Cat (2006). Nutrient requirements of dogs and cats ([Rev. ed.] ed.). Washington, D.C.: National Academies Press. ISBN 978-0309086288. OCLC 62741464.
  31. ^ a b Debier, C.; Larondelle, Y. (February 2005). "Vitamins A and E: metabolism, roles and transfer to offspring". The British Journal of Nutrition. 93 (2): 153–174. doi:10.1079/bjn20041308. ISSN 0007-1145. PMID 15788108.
  32. ^ a b c Lee, Je Min; Lee, Hyungjae; Kang, SeokBeom; Park, Woo Jung (2016-01-04). "Fatty Acid Desaturases, Polyunsaturated Fatty Acid Regulation, and Biotechnological Advances". Nutrients. 8 (1): 23. doi:10.3390/nu8010023. PMC 4728637. PMID 26742061.

Further reading edit

  • Fogle, Bruce (2000). "The Breed Section Explained". The New Encyclopedia of the Dog. Dorling Kindersley. p. 83 and various. ISBN 978-0-7513-0471-8.

External links edit

  • Schmutz, Sheila M. (March 4, 2010). "Dog Coat Color Genetics". University of Saskatchewan. Retrieved September 12, 2010.

coat, this, article, about, natural, garments, worn, dogs, animal, covering, coats, made, from, clothing, coat, domestic, refers, hair, that, covers, body, dogs, demonstrate, wide, range, coat, colors, patterns, textures, lengths, coat, variation, dogas, with,. This article is about a dog s natural fur For garments worn by dogs see Rug animal covering For coats made from dog fur see Fur clothing The coat of the domestic dog refers to the hair that covers its body Dogs demonstrate a wide range of coat colors patterns textures and lengths Coat variation of the dogAs with other mammals a dog s fur has many uses including thermoregulation and protection from cuts or scratches furthermore a dog s coat plays an important role in the showing of purebred dogs Breed standards often include a detailed description of the nature and attributes of that breed s ideal coat A dog s coat is composed of two layers a top coat of stiff guard hairs that help repel water and shield from dirt and an undercoat of soft down hairs to serve as insulation 1 Dogs with both under coat and top coat are said to have a double coat Dogs with a single coat have a coat composed solely of guard hairs with little or no downy undercoat The terms fur and hair are often used interchangeably when describing a dog s coat however in general a double coat like that of the Newfoundland and most livestock guardian dogs is referred to as a fur coat while a single coat like that of the Poodle is referred to as a hair coat Contents 1 Genetics 2 Nomenclature of colours and patterns 2 1 Colors 2 1 1 Brown chocolate liver 2 1 2 Red 2 1 3 Gold and yellow 2 1 4 Cream 2 1 5 Fawn 2 1 6 Black 2 1 7 Blue 2 1 8 Grey 2 1 9 White 2 2 Patterns 3 Length and texture 4 Shedding 4 1 Hypoallergenic coat 5 Show coats 6 Nutritional impacts on coat 6 1 Trace minerals 6 1 1 Zinc 6 1 2 Copper 6 1 3 Selenium 6 2 Vitamins 6 2 1 Vitamin A 6 2 2 Vitamin B7 Biotin 6 3 Essential fatty acids 6 3 1 Omega 3 linolenic acid 6 3 2 Omega 6 linoleic acid 7 See also 8 References 9 Further reading 10 External linksGenetics editMain article Dog coat genetics nbsp A Labrador exhibiting a yellow coat colourDomestic dogs exhibit diverse coat colours and patterns In many mammals different colour patterns are the result of the regulation of the Agouti gene which can cause hair follicles to switch from making black or brown pigments to yellow or nearly white pigments The most common coat pattern found in modern wolves is agouti in which the upperside of the body has banded hairs and the underside exhibits lighter shading The colour yellow is dominant to the colour black and is found in dogs across much of the world and the dingo in Australia 2 In 2021 a study of whole genome sequences taken from dogs and wolves focused on the genetic relationships between them based on coat colour The study found that most dog colour haplotypes were similar to most wolf haplotypes however dominant yellow in dogs was closely related to white in arctic wolves from North America This result suggests a common origin for dominant yellow in dogs and white in wolves but without recent gene flow because this clade was found to be genetically basal to the golden jackal and genetically distinct from all other canids The most recent common ancestor of the golden jackal and the wolf lineage dates back to 2 million years ago The study proposes that 35 000 years ago there was genetic introgression into the Late Pleistocene grey wolf from a ghost population of an extinct canid which had diverged from the grey wolf lineage over 2 million years ago This colour diversity could be found 35 000 years ago in wolves and 9 500 years ago in dogs A closely related haplotype exists among those wolves of Tibet which possess yellow shading in their coats The study explains the colour relationships between modern dogs and wolves white wolves from North America yellow dogs and yellowish wolves from Tibet The study concludes that during the Late Pleistocene natural selection laid the genetic foundation for modern coat colour diversity in dogs and wolves 2 During evolution of the dog from their wolf ancestors coat colors in dogs were probably the inadvertent outcome of some other selective process and were not likely initially selected for intentionally by humans 3 Research has found that tameness brings associated physical changes including coat colouring and patterning 4 Domestic dogs often display the remnants of countershading a common natural camouflage pattern The basic principle of countershading is when the animal is lit from above shadows will be cast on the ventral side of the body These shadows could provide a predator or prey with visual cues relating to the movement of the animal By being lighter colored on the ventral side of the body an animal can counteract this and thereby fool the predator or prey An alternative explanation is that the dorsal and ventral sides of an animal experience different selection pressures from the need to blend into different backgrounds when viewed from above and below resulting in differing coloration 5 Nomenclature of colours and patterns editColors edit The same colour may be referred to differently in different breeds Likewise a same term may mean different colourations in different breeds Brown chocolate liver edit Brown chocolate and liver are the most common terms used to refer to the bb dilution of black pigment to a dark brown Depending on breed and exact shade terms such as mahogany midtone brown grey brown blackish brown are used Sedge and deadgrass are used to describe the desired Chesapeake Bay Retriever color that resembles that of its working surroundings as closely as possible nbsp Brown Chesapeake Bay Retriever nbsp Red Australian Kelpie nbsp Dark and light chocolate Labrador RetrieversRed edit Red refers to reddish shades of orange brown and tan Terms used include orange red gold cinnamon tan and ruby Genetically a dog called red is usually a clear sable with little to no eumelanin tipping on hairs or a ruddy recessive yellow In some breeds red refers to what would usually be called brown chocolate or liver A red merle is always a liver based merle In Australian Cattle Dogs blue stands for a densely ticked liver based colouration with an overall red grey appearance nbsp Red Irish Setter nbsp Red Chow Chow nbsp Red Standard Poodle nbsp Ruby Cavalier King Charles Spaniel nbsp Red Australian Cattle Dog nbsp Red Shiba Inu nbsp Red Basset Fauve de Bretagne nbsp Red Cocker Spaniel nbsp VizslaGold and yellow edit Gold refers specifically to a rich reddish yellow and its variants whereas yellow can refer to any shade of yellow and tan Terms used include yellow gold lion colored fawn apricot wheaten tawny straw yellow red mustard sandy honey blond and lemon Dogs called golden or yellow tend to be recessive yellow but can also be sable nbsp Apricot Poodle nbsp Dark Golden Retrievers nbsp Yellow Dachshund nbsp Yellow Labrador Retriever nbsp Dark Golden Golden Retriever nbsp Orange Pomeranian dog nbsp Yellow mixed breed of unknown parentage Cream edit Cream refers to a pale yellowish or tannish colour which can be almost white nbsp Pale cream Standard Poodle nbsp Cream French Bulldog nbsp Cream AkitaFawn edit Fawn typically refers to a yellow tan light brown or cream dog that has a dark melanistic mask With Weimaraners fawn refers to their typical brownish grey colouration that with other breeds is usually called lilac nbsp Silver Fawn Pug nbsp Fawn English Mastiff nbsp Fawn Belgian Shepherd Malinois nbsp Fawn Boxer nbsp Fawn BoerboelBlack edit Black is a pure black that can get grizzled as the dog ages or have a tendency to gain a brownish cast when exposed to the elements nbsp Newfoundland nbsp Black Labrador Retriever nbsp Black Schipperke nbsp Black SchnauzerBlue edit Blue is a cool toned metallic grey It typically means a d d dilution of black pigment a grey colouration that is grey from birth but has a wide range of breed specific meanings In Kerry Blue Terriers Poodles and Bearded Collies blue refers to colouration that is black at birth and progressively greys out as the dog matures In Australian Shepherds Rough Collies and Shetland Sheepdogs blue means a blue black based merle In Australian Silky Terriers blue means a saddle type black and tan pattern where the black parts of the coat progressively fade to a steel grey as the dog matures and in Australian Cattle Dogs blue stands for a densely ticked black based colouration with an overall blue grey appearance nbsp Blue Neapolitan Mastiff nbsp Blue mixed breed dog nbsp Blue Australian Silky Terrier nbsp Blue Australian Cattle DogGrey edit Grey simply means a grey colouration of any shade It can be used as an alternative synonym of blue but tends to mean some other type of grey than the d d dilution of black Synonyms include silver pepper grizzle slate blue black grey black and silver steel Greys of a dusty or brownish cast are often lilac a d d dilution of liver and this colouration does not have much of a commonly recognised name Across various breeds it is called lavender silver fawn isabella fawn cafe au lait or silver beige In Poodles a blue is a very slowly fading very dark steel grey whereas a silver is a quicker to clear much lighter grey that can range from a pale platinum to a steel grey Both are black at birth with minimal markings to indicate future change Similarly cafe au lait is a slower and darker and silver beige a quicker and lighter progressively greying brown i e liver nbsp Lighter and darker fawn Weimaraners nbsp Silver Miniature Schnauzer nbsp Silver Miniature Poodle nbsp Isabella fawn DobermannWhite edit White Such a light cream that it is seen and described as pure white making them distinct from albino dogs A white dog as opposed to an albino one has dark pigment around the eye rims and nose often coupled with dark colored eyes There is often some coat identifiable as cream between the dog s shoulder blades Extreme piebald dogs can also appear all white but are caused by a separate factor nbsp White American Eskimo Dog nbsp White Bichon Frise nbsp White Maltese dog nbsp White Coton de Tulear puppy nbsp White Japanese Spitz nbsp Samoyed dog nbsp West Highland White TerrierPatterns edit The same pattern may be referred to differently in different breeds nbsp Black and Tan Dachshund nbsp Black and tan Miniature Pinscher Black and tan liver and tan blue and tan Coat has both colors but in clearly defined and separated areas usually with the darker color on most of the body and tan reddish variants underneath and in highlights such as the eyebrows Black and brindle and liver and brindle in which the same pattern is evident with brindling in place of tan are also possible but less common nbsp Black and white Border Collie nbsp Blenheim Red brown and white Cavalier King Charles Spaniel Piebald or pied also called bicolor tricolor Irish spotted Flashy Patched Tuxedo any color or pattern coupled with white spotting This can range anywhere from white toes and tail tip to a mostly white dog with color around the base of the ears and tail Some breeds have special names for the color 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 The piebald gene is responsible for this pattern nbsp Extreme piebald Borzoi with small colored patches nbsp Piebald white Dogo Argentino Extreme piebald or piebald white an extensive piebald pattern that renders the dog mostly or all white with pink skin Usually some pigmented specks remain Governed by the piebald gene nbsp Tricolor Basset Hound nbsp Tricolor Beagle Tricolor Three clearly defined colors usually either black liver or blue on the dog s upper parts white underneath with a tan border between and tan highlights for example the Smooth Collie the Rough Collie the Papillon or the Sheltie Tricolor can also refer to a dog whose coat is patched usually two colors such as black and tan on a white background nbsp Blue merle tricolor Shetland Sheepdog nbsp Red merle Catahoula Leopard Dogs Merle Marbled coat with darker patches and spots of the specified color Merle is referred to as Dapple in Dachshunds nbsp Tuxedo Lab mix nbsp Tuxedo Collie mix Tuxedo Solid often black with a white patch shirt front on the chest and chin and white on some or all of the feet spats The tuxedo pattern is common in dogs that carry only one piebald gene a heterozygous carrier nbsp Harlequin Great Dane nbsp Harlequin Great Dane Harlequin ripped splotches of black on white The Great Dane is the only breed with this pattern The term harlequin is also sometimes used to describe a piebald spotting pattern such as parti colored poodles nbsp Spotted Dalmatian nbsp Spotted mutt in Sinamaica Venezuela Spotted Coin sized pigmented spots on a white background The spotting on Dalmatians is unique as it involves mutations in at least three different spotting genes 6 nbsp Red speckled Australian Cattle Dog nbsp Liver ticked German Shorthaired Pointer Flecked ticked speckled also called belton in English Setters nbsp Orange belton orange and white speckled English Setter nbsp Blue speckled Australian Cattle Dog nbsp Brown brindle and white Boxer nbsp Very sparsely brindled Great Dane Brindle A mixture of black liver blue lilac and red yellow cream arranged in a vertical tiger stripe pattern nbsp Airedale Terrier with large black saddle nbsp Norwegian Dunker with merle affected black saddle Saddle or blanket A different color usually darker over the centre of the back nbsp Dark orange sable Pomeranian nbsp Sable Pembroke Welsh Corgi Sable Black tipped hairs overlaid onto a different coloured lighter background including grey silver and gold 7 nbsp Hairless Chinese Crested Dog nbsp Xoloitzcuintle Hairless Some dogs are born without a fur coat Length and texture edit nbsp nbsp Bearded Collie top with facial furnishings vs border collie bottom no furnishings For more detail see Genes associated with hair length growth and texture Dogs demonstrate an enormous diversity in coat length and texture from the very short and smooth coat seen in the vizslas to the wiry coat of a Scottish Terrier and the corded coat of the Puli and the Komondor Generally coats vary along three categories length long vs short texture curly vs straight and coarseness wire haired vs non wire These three categories all interact with one another thus one can see a short curly and wired coat in the Wirehaired Pointing Griffon and a long straight and non wired coat in the Pomeranian 8 Additionally breeds show variation in patterns of growth that is to say parts of the dog s body where the coat may be longer or shorter The same gene that controls wiriness of hair also causes furnishings to be present e g beard moustache eyebrows 8 compare the bearded collie furnishings present to the border collie which lacks furnishings Some breeds show feathering fringes of longer hair on the ears belly tail and back of the legs e g Saluki and any of the setters Dogs also vary in the thickness of the undercoat Some dogs have only a single rather than a double coat or a very reduced undercoat e g the Vizsla which results in a thinner coat Certain breeds especially spitz type breeds tend to have a thicker undercoat which helps retain heat in cold and wet weather Furthermore complete hairlessness on parts of the body is present in breeds such as the Chinese Crested or the Xoloitzcuintli Shedding edit nbsp A slicker brush with wire bristles used for removing loose hair from the coat Shedding of hair can occur continuously but in many breeds is strongly influenced by hormones Seasonal shedders shed most in spring and fall following an increase or decrease in day length and least in summer and winter in response to constant day length Cold temperatures stimulate hair growth so that the heaviest shedding is in spring on dogs living in cold climates Artificial lighting can alter the seasonal shedding pattern of dogs who live indoors Other hormonal influences include dietary factors reproductive hormones in intact dogs and various medical conditions and disorders Shedding that is done in a short period of time is known as blowing the coat or blowing coat 9 10 Among the other coat types dogs with fine silky coats e g spaniels are generally moderate shedders those with an intermediate coat texture e g mountain dogs are generally heavy shedders and those with thick stand offish coats e g spitzes are generally very heavy shedders nbsp The Portuguese Water Dog is an example of a breed with single low shedding coat Non shedding dogs have greatly reduced shedding due to alterations to the hair follicle growth cycle homozygosity for the furnishings wire allele Most breeds with facial furnishings including ones whose faces are usually shaved removing the furnishings are low shedding but they must be homozygous so dogs of mixed wire non wire parentage e g terrier crosses or breeds with wire and non wire varieties can be heavy shedders There are a few furnished breeds that shed more e g Old English Sheepdog Bearded Collie Briard Otterhound at least one copy of the single coat non shedding allele Most dogs with a smooth coat are low shedding as well as the fringed or flat coat There are breeds with a very short coat that shed more e g Basset Hound English Bulldog Pug Toy Fox Terrier Dalmatian Vizsla German Shorthaired Pointer single coat no undercoat plus furnishings homozygous These breeds shed the least e g Poodle Soft coated Wheaten Terrier Hypoallergenic coat edit Main article Hypoallergenic dog breed D ogs are a relevant source of allergens but diagnosing dog related allergies may present difficulties 11 Some dog breeds have been promoted as hypoallergenic which means less allergic not free of allergens because they shed very little However no canine is known to be completely nonallergenic Often the problem is with the dog s saliva or dander not the fur 12 Although breeds such as poodles bedlingtons bichons yorkies and wire haired terriers are commonly represented as being hypoallergenic due to reduced shedding the reaction that an individual person has to an individual dog may vary greatly In a report describing dog allergen extracts of dog hair belonging to patients dogs or from dogs of the same breed with low molecular mass that are absent in extracts of commercial allergen test kits it has been found that f actors related to individual dogs seem to influence the allergenicity more than breed or gender 11 Show coats editThe 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 Nutritional impacts on coat editA dog s coat is an outward indicator of internal well being 13 For this reason coat health is an important aspect of pet care to many dog owners 13 Dog coats can be impacted by nutritional components from the diet 14 Below is a table that summarizes the effects of several nutrients minerals vitamins on the domestic canine coat based on current evidence Nutrient Role Impacts when deficient BenefitsZinc Gives strength to collagen 15 Dry and brittle coat 15 Contributes to coat growth and prevents brittle and dry coat 15 Copper Involved in keratinization 16 Brittle fur hypo pigmentation discoloration 16 Improved color and keratinization 16 Selenium Cell growth antioxidant 17 18 Sparse coat growth 17 Coat growth promotion 18 Vitamin A Proliferation of keratinocytes 19 Rough coat 19 Proliferation of keratinocytes hair follicle growth 20 19 Biotin Saturation of Coat 21 Alopecia and achromotrichia beginning at the root of the coat 21 Contributes to coat shine thickness distribution of hair follicles 21 Trace minerals edit Zinc edit Main article Zinc Zinc contributes to hair growth and can prevent hair from becoming dry and brittle 15 In addition to zinc when supplemented in combination with linoleic acids has been found to improve the coat of canines by reducing water loss in the trans epidermal layer of the skin 22 Dogs can obtain zinc in their diet through the addition of various ingredients including red meats whole grains poultry by product meals and fish meals Copper edit Main article Copper Copper is a trace mineral that is required in the diet of canines at 7 3 mg kg 23 Copper is involved in multiple enzymatic pathways In dogs a lack of copper in the diet leading to a copper deficiency results in incomplete keratinization 16 This leads to a dry coat hypo pigmentation and discoloration of the coat 16 Selenium edit Main article Selenium in biology Selenium is another one of the many trace minerals essential for a dog s diet Selenium is typically required in lower levels in comparison to other minerals It is involved in the prevention of oxidative damage as well as the production of anti oxidants 17 Selenium aids in the promotion of coat growth 24 Lack of selenium in the diet of a dog can contribute to the occurrence of sparse coat growth 25 Dogs can obtain selenium in their diet through the addition of various ingredients including tuna fish halibut sardines beef chicken and egg Vitamins edit Main article Vitamin Vitamin A edit Main article Vitamin A Vitamin A deficiency can lead to rough coat scaling of skin and other dermatitis issues like alopecia 19 It is also essential for cells to properly proliferate keratinocytes 19 which are epithelial cells that produce keratin on the outermost layer of the skin for the cortisol cells of the hair follicle 20 A deficiency in vitamin A can cause the common symptoms of dermatitis dry scaling skin and dull coat 26 Vitamin B7 Biotin edit Main article Biotin Vitamin B7 also known as biotin is a water soluble nutrient that is known to play a role associated with the maintenance and development of hair starting from the follicle Although it has not been clinically shown to improve hair growth with supplementation alone it has been shown to reverse deficiency in dogs born deficient 27 Symptoms of biotin deficiency include alopecia and achromotrichia A clinical study of biotin showed the importance of biotin in coat pigmentation There different stages of hair development as shown in clinical studies using mice 21 Each stage of hair development has a different sensitivity to biotin present in the body For example the shaft development is not greatly affected by biotin access 21 During the last stage the amount of biotin available for use by the body will alter the success of that development greatly 21 Throughout the hair development most stages of growth are completed but it was found that in the last stage where biotin levels were insufficient there was an incorrect keratinization of the root of the hair causing the hair to fall out of the body 21 The supplementation of biotin cannot reverse affects caused by deficiency but as soon as supplementation is given and biotin levels are restored to adequacy the body begins to produce the usual hair growth and color it would before the deficiency took place 21 Essential fatty acids edit Polyunsaturated fatty acids found in the diet play a critical role in the maintenance of a healthy coat in dogs and have even been shown to improve coat condition when supplemented in the diet 14 Furthermore diets lacking essential fatty acids in their diet will manifest as unkept matted coat 13 Omega fatty acids 3 and 6 are highly unsaturated fatty acids making them especially metabolically active 28 The proper combination of these omega fatty acids is crucial to achieve optimal benefits Proper omega 6 3 ratios have been shown to diminish allergy triggered immune responses thus improving overall coat condition 29 The National Research Council NRC recommends a 2 6 1 to 26 1 omega 6 3 ratio for adult dog maintenance diets 30 The proper ratio of these fatty acids is crucial because each has an opposing role in inflammation within the body and both compete for the same enzymatic pathway 13 Dogs like many mammals lack the desaturase enzymes capable of interconverting omega 3 and 6 fatty acids 28 Therefore the amount of inflammation in the body is dependent on the ratio between omega 3 and 6 fatty acids Too little inflammation suppresses the immune system and the body s ability to heal however excessive inflammation can irritate the skin and reduce the coat s overall appearance 13 Aside from omega fatty acids lipid content in the canine diet is an important aspect of coat health 13 The fat soluble vitamins A D E and K require lipids present in the diet for absorption transport and deposition in canine adipose tissue 31 The specific role of vitamins A and E for coat health are explored elsewhere in this article as they pertain to immune function 31 Another pet food regulating body the Association of American Feed Control Officials AAFCO recommends that Vitamin E supplementation increase as polyunsaturated fatty acids are added to diet in order to counteract lipid oxidation and maintain the potency 23 In addition high fat diets in dogs were shown to dramatically improve coat sheen and appearance 13 It is thought excess cholesterol esters are incorporated into the hair follicle leading to the improved coat appearance 13 The same study by Kirby Hester and Bauer 2007 stated the optimal approach to an improved coat in dogs is a combination of increased dietary fat and the proper amount of polyunsaturated fatty acids 13 Omega 3 linolenic acid edit Main article Omega 3 fatty acid Omega 3 fatty acid also known as linolenic acid is an anti inflammatory compound 29 Linolenic acid is found in the oil from flaxseeds soybean and canola 29 Some better known examples of linolenic acid are the metabolic derivatives eicosapentaenoic acid EPA and docosahexanoic acid DHA EPA inhibits the enzyme delta 5 desaturase which prevents the synthesis of arachidonic acid which is an inflammatory omega 6 32 DHA acts even earlier in omega 6 metabolism by inhibiting delta 6 desaturase 32 The anti inflammatory properties of omega 3s stem from their ability to inhibit the inflammatory action of omega 6 fatty acids A functional minimum has not been set forth by AAFCO as one has yet to be determined 23 A reduction in inflammation of somatic tissues skin especially supports coat health 13 Omega 6 linoleic acid edit Main article Omega 6 fatty acid Omega 6 fatty acid also known as linoleic acid is found in poultry fat and the oil from safflower sunflower corn and flaxseed 29 Arachidonic acid is a well known metabolic derivative of linoleic acid found only in animal sources 29 As mentioned above arachindonic acid is a pro inflammatory compound 32 It is critical to note once again that canines are unable to interconvert between omega fatty acids and over supplying linoleic acid promotes excessive inflammation in the body which can potentially reverse the coat benefits seen by supplying omega fatty acids in the diet In contrast linoleic acid is also required for epidermal lipid function and water retention which benefits coat shine 22 29 Having linoleic acid present in the diet has demonstrated a positive effect on skin and thus by extension coat 13 See also editChiengora Dog grooming Dog skin disorders Hypoallergenic List of dog breeds Merle coat color in dogs References edit How to Keep Your Dog Warm This Winter Spoiled Pets Shop 2014 Retrieved November 10 2014 a b Bannasch Danika L et al 2021 Dog colour patterns explained by modular promoters of ancient canid origin Nature Ecology amp Evolution 5 10 1415 1423 doi 10 1038 s41559 021 01524 x PMC 8484016 PMID 34385618 James Serpell ed 1995 The Domestic Dog Its Evolution Behaviour and Interactions with People Cambridge United Kingdom Cambridge University Press p 284 ISBN 978 0 521 42537 7 Lyudmila N Trut March April 1999 Early Canid Domestication The Farm Fox Experiment American Scientist 87 2 160 169 Bibcode 1999AmSci 87 T doi 10 1511 1999 2 160 Graeme D Ruxton Michael P Speed David J Kelly September 2004 What if anything is the adaptive function of countershading Animal Behaviour 68 3 445 451 doi 10 1016 j anbehav 2003 12 009 S2CID 43106264 Edward J Cargill1 Thomas R Famula Robert D Schnabel George M Strain amp Keith E Murphy July 2005 The color of a Dalmatian s spots Linkage evidence to support the TYRP1 gene Vol 1 p 1 doi 10 1186 1746 6148 1 1 ISBN 978 1 74661 481 2 PMC 1192828 PMID 16045797 a href Template Cite book html title Template Cite book cite book a journal ignored help CS1 maint multiple names authors list link CS1 maint numeric names authors list link Cunliffe Juliette 2004 Coat Types Colors and Markings The Encyclopedia of Dog Breeds Paragon Publishing pp 20 23 and various ISBN 978 0 7525 8276 4 a b Elaine Cadieu Edouard Neff Mark Quignon Pascale Walsh Kari Chase Kevin Parker Heidi Vonholdt Bridgett Rhue Alison Boyko Adam Byers Alexandra Wong Aaron Mosher Dana Elkahloun Abdel Spady Tyrone Andre Catherine Lark K Gordon Cargill Michelle Bustamante Carlos Wayne Robert Ostrander Coat variation in the domestic dog is governed by variants in three genes OCLC 799147453 Blackburn Sandy 2008 The Everything Dog Grooming Book All you need to help your pet look and feel great Avon Massachusetts Simon amp Schuster p 110 ISBN 978 1440512148 Retrieved 2017 07 04 Dog Fancy 2011 Pug New York Lumina Media p 36 ISBN 978 1593788391 Retrieved 2017 07 04 a b Heutelbeck AR Schulz T Bergmann K Hallier E Jan 2008 Environmental Exposure to Allergens of Different Dog Breeds and Relevance in Allergological Diagnostics Journal of Toxicology and Environmental Health Part A 71 11 12 751 8 doi 10 1080 15287390801985513 PMID 18569573 S2CID 37091773 Grady Denise February 5 1997 Nonallergenic Dog Not Really New York Times Retrieved April 3 2011 a b c d e f g h i j k Kirby Naomi A Hester Shaleah L Bauer John E 2007 Dietary fats and the skin and coat of dogs Journal of the American Veterinary Medical Association 230 11 1641 1644 doi 10 2460 javma 230 11 1641 PMID 17542730 a b Watson Tim D G 1998 12 01 Diet and Skin Disease in Dogs and Cats The Journal of Nutrition 128 12 2783S 2789S doi 10 1093 jn 128 12 2783S ISSN 0022 3166 PMID 9868266 a b c d Goldberg L Lenzy Y 2010 Nutrition and hair Clinics in Dermatology 28 4 412 419 doi 10 1016 j clindermatol 2010 03 038 PMID 20620758 a b c d e Tewari Singh Gautam Dwivedi December 2013 Nutritional dermatosis a review Intas Polivet 14 199 202 via GALE a href Template Cite journal html title Template Cite journal cite journal a CS1 maint multiple names authors list link a b c Guo E Katta R 2017 Diet and hair loss effects of nutrient deficiency and supplement use Dermatol Pract Concept 7 1 1 10 doi 10 5826 dpc 0701a01 PMC 5315033 PMID 28243487 a b Kapun A Plevnik Salobir J Levart A Kalcher G Tavcar Svete A Nemec Kotnik T 2014 12 06 Vitamin E supplementation in canine atopic dermatitis improvement of clinical signs and effects on oxidative stress markers Veterinary Record 175 22 560 doi 10 1136 vr 102547 ISSN 0042 4900 PMID 25205675 S2CID 23201891 a b c d e Baviskar Jayanthy amp Nagarajan 2013 Vitamin a responsive dermatosis in a dog Intas Polivet 14 210 a b Kurtenbach Stefan Mayer Christoph Pelz Thomas Hatt Hanns Leese Florian Neuhaus Eva M 2011 08 09 Molecular evolution of a chordate specific family of G protein coupled receptors BMC Evolutionary Biology 11 234 doi 10 1186 1471 2148 11 234 ISSN 1471 2148 PMC 3238225 PMID 21827690 a b c d e f g h Rauch Harold 1952 The Effects of Biotin Deficiency on Hair Development and Pigmentation Physiological Zoology 25 2 145 149 doi 10 1086 physzool 25 2 30158351 JSTOR 30158351 S2CID 87665589 a b Marsh K Coe S Ruedisueli F Watson T 2000 Effects of zinc and linoleic acid supplementation on the skin and coat quality of dogs receiving a complete and balanced diet Veterinary Dermatology 11 4 277 284 doi 10 1046 j 1365 3164 2000 00202 x a b c The Association of American Feed Control Officials gt Publications www aafco org Retrieved 2017 11 28 Hatfield D Tsuji P Carlson B Gladyshev V 2014 Selenium and selenocysteine roles in cancer health and development Trends Biochem Sci 39 3 112 120 doi 10 1016 j tibs 2013 12 007 PMC 3943681 PMID 24485058 Sengupta A Lichti U Carlson B Ryscavage A Gladyshev V Yuspa S Hatfield D 2010 Selenoproteins are essential for proper keratinocyte function and skin development PLOS ONE 5 8 e12249 Bibcode 2010PLoSO 512249S doi 10 1371 journal pone 0012249 PMC 2923614 PMID 20805887 Beigh S A Soodan J S Bhat A M Singh V Tantary H 2013 Clinical diagnosis and management of vitamin a responsive canine dermatosis Intas Polivet 14 2 207 210 Zempleni Janos Hassan Yousef I Wijeratne Subhashinee SK 2008 11 01 Biotin and biotinidase deficiency Expert Review of Endocrinology amp Metabolism 3 6 715 724 doi 10 1586 17446651 3 6 715 ISSN 1744 6651 PMC 2726758 PMID 19727438 a b Murru Elisabetta Banni Sebastiano Carta Gianfranca 2013 Nutritional Properties of Dietary Omega 3 Enriched Phospholipids BioMed Research International 2013 965417 doi 10 1155 2013 965417 ISSN 2314 6133 PMC 3747496 PMID 23984423 a b c d e f Canine and feline nutrition a resource for companion animal professionals Case Linda P 3rd ed Maryland Heights Mo Mosby 2011 ISBN 9780323066198 OCLC 664112342 a href Template Cite book html title Template Cite book cite book a CS1 maint others link Nutrition National Research Council U S Ad Hoc Committee on Dog and Cat 2006 Nutrient requirements of dogs and cats Rev ed ed Washington D C National Academies Press ISBN 978 0309086288 OCLC 62741464 a b Debier C Larondelle Y February 2005 Vitamins A and E metabolism roles and transfer to offspring The British Journal of Nutrition 93 2 153 174 doi 10 1079 bjn20041308 ISSN 0007 1145 PMID 15788108 a b c Lee Je Min Lee Hyungjae Kang SeokBeom Park Woo Jung 2016 01 04 Fatty Acid Desaturases Polyunsaturated Fatty Acid Regulation and Biotechnological Advances Nutrients 8 1 23 doi 10 3390 nu8010023 PMC 4728637 PMID 26742061 Further reading editFogle Bruce 2000 The Breed Section Explained The New Encyclopedia of the Dog Dorling Kindersley p 83 and various ISBN 978 0 7513 0471 8 External links editSchmutz Sheila M March 4 2010 Dog Coat Color Genetics University of Saskatchewan Retrieved September 12 2010 Retrieved from https en wikipedia org w index php title Dog coat amp oldid 1181057168, wikipedia, wiki, book, books, library,

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