Physical characteristics

Coat Main article: Coat (dog) A heavy winter coat with countershading in a mixed-breed dog The coats of domestic dogs are of two varieties: "double" being common with dogs (as well as wolves) originating from colder climates, made up of a coarse guard hair and a soft down hair, or "single", with the topcoat only. Domestic dogs often display the remnants of countershading, a common natural camouflage pattern. A countershaded animal will have dark coloring on its upper surfaces and light coloring below,[124] which reduces its general visibility. Thus, many breeds will have an occasional "blaze", stripe, or "star" of white fur on their chest or underside.[125] Tail See also: Docking There are many different shapes for dog tails: straight, straight up, sickle, curled, or cork-screw. As with many canids, one of the primary functions of a dog's tail is to communicate their emotional state, which can be important in getting along with others. In some hunting dogs, however, the tail is traditionally docked to avoid injuries.[126] In some breeds, such as the Braque du Bourbonnais, puppies can be born with a short tail or no tail at all. The coat of the domestic dog (Canis lupus familiaris) refers to the hair that covers its body. A dog's coat may be a double coat, made up of a soft undercoat and a coarser topcoat, or a single coat, which lacks an undercoat. The terms fur and hair are often used interchangeably when describing a dog's coat, however in general, a double coat, e.g., like that of the Newfoundland and most mountain dogs, is referred to asThere are a greater variety of coat colors, patterns, lengths and textures found in the domestic dog than in its wolf relations, even though dogs and wolves belong to the same species (Canis lupus). Different breeds use different names for longhaired and shorthaired types, there is no standard nomenclature for length, breed standards give acceptable lengths by measurement. Coat colors in dogs were not likely initially selected for by humans but were probably the inadvertent outcome of some other selection process (i.e. selection for tameness).[1] Research has found that tameness brings associated physical changes, including coat coloring and

patterning.[2] 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 in to different backgrounds when viewed from above and below) resulting in differing coloration. Coat is the nature and quality of a mammal's pelage. It is important to the animal fancy in the judging of the animal, particularly at conformation dog shows, cat shows and horse shows. It may also be used as a standard to evaluate the quality of care and management used by the animal hander, such as in horse showmanship. The pelage of a show animal may be divided into different types of hair, fur or wool with a texture ranging from downy to spiky; in addition the animal may be single-coated or may have a number of coats, such as an undercoat and a topcoat (made up of guard hairs; also called outer coat and, sometimes, overcoat). The state of the coat is considered an indication of the animal's breeding and health. Animals might have different coat quality depending on the season. Normally, animals with fur or hair body coats may develop a thicker and/or longer winter coat in colder times of the year, which will shed out to a shorter, sleeker summer coat as the days lengthen into spring and summer. This process may not occur in a very noticeable fashion in climates that are warm year-round, though animals may nonetheless shed their coats periodically. The process may also be minimized by artificially keeping the animal blanketed, or, in the case of small animals, housed indoors. Pinnipeds and Polar Bears have longer guard hairs forming the most visible fur;[1] polar bears' guard hairs are hollow. a fur coat, while a single coat, like that of the Poodle, is referred to as a hair coat.