Dog coat

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.

[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 most recent common ancestor of the golden jackal and the wolf lineage dates back to 2 million years ago.

The study concludes that during the Late Pleistocene, natural selection laid the genetic foundation for modern coat colour diversity in dogs and wolves.

[3] Research has found that tameness brings associated physical changes, including coat colouring and patterning.

Sedge and deadgrass are used to describe the desired Chesapeake Bay Retriever color that resembles "that of its working surroundings" as closely as possible.

Genetically a dog called red is usually a clear sable (with little to no eumelanin tipping on hairs) or a ruddy recessive yellow.

In Australian Cattle Dogs, "red" stands for a densely ticked liver-based colouration with an overall red-grey appearance.

Terms used include yellow-gold, lion-colored, fawn, apricot, wheaten, tawny, straw, yellow-red, mustard, sandy, honey, blond, and lemon.

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

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.

Similarly, café au lait is a slower and darker and silver beige a quicker and lighter progressively greying brown, i.e. liver.

Generally, coats vary along three categories: length (long vs. short), texture (curly vs. straight), and coarseness (wire-haired vs. non-wire).

[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.

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).

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

[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.

[25] Dogs can obtain selenium in their diet through the addition of various ingredients including; tuna fish, halibut, sardines, beef, chicken, and egg.

[20] A deficiency in vitamin A can cause the common symptoms of dermatitis (dry, scaling skin and dull coat).

[26] 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.

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] 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] 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.

In contrast, linoleic acid is also required for epidermal lipid function and water retention, which benefits coat shine.