Physical Attributes of Dogs

Dogs are Color Blind
Dogs are dichromats and thus, by human standards, color blind. Because the lenses of dogs' eyes are flatter than humans', they cannot see as much detail; on the other hand, their eyes are more sensitive to light and motion than humans' eyes. Some breeds, particularly the best sighthounds, have a field of vision up to 270° (compared to 100° to 120° for humans), although broad-headed breeds with their eyes set forward have a much narrower field of vision, as low as 180°.1, 2

The Hearing of Dogs
Dogs detect sounds as low as the 20 to 70 Hz frequency range (compared to 16 to 20 Hz for humans) and as high as 70,000 to 100,000 Hz (compared to 20,000 Hz for humans)2, and in addition have a degree of ear mobility that helps them to rapidly pinpoint the exact location of a sound. They can identify a sound's location much faster than can a human, and they can hear sounds up to four times the distance that humans can.

Sense of Smell
Dogs have about 220 million smell-sensitive cells (compared to 5 million for humans). Some breeds have been selectively bred for excellence in detecting scents, even compared to their canine brethren.

All dogs have a tremendous capacity to learn complex social behavior and to interpret varied body language and sounds, and, like many predators, can react to and learn from novel situations.

Dog Coats, Colors, and Markings
Coat colors range from pure white to solid black and many other variations. Dogs exhibit a diverse array of coat textures, colors, and markings, and a specialized vocabulary has evolved to describe them.

Originally, dogs all had dense fur with an undercoat and long muzzles and heads, although both of these features have been altered in some of the more extremely modified breeds, such as the Mexican Hairless and the English Bulldog.

One often refers to a specific dog first by coat color rather than by breed; for example, "a blue merle Aussie" or "a chocolate Lab". Coat colors include:

Blenheim: A combination of chestnut and white; for example, the Cavalier King Charles Spaniel.

Black: Usually pure black but sometimes grizzled, particularly as dogs age and develop white hairs, usually around the muzzle.

Black and tan: Coat has both colors but in clearly defined and separated areas; usually the top and sides are black and lower legs and underside are tan, reddish, or chestnut.

Blue: A dark metallic gray, often as a blue merle or speckled (with black). Kerry Blue Terriers, Australian Silky Terriers, Bearded Collies, and Australian Shepherds are among many breeds that come in blue.

Brown: Includes dark mahogany, midtone brown, gray-brown, and very dark brown. (Weimaraners are often described as "steel-grey" but they are in fact light brown, the colour of the powder for instant hot chocolate.)

Cream: Depending on the breed and individual, ranges from white through ivory and blond, often occurring with or beneath lemon, yellow, and sable.

Gold: Rich reddish-yellow, as in a Golden Retriever; often includes colors such as yellow-gold, lion-colored, fawn, apricot, wheaten, tawny, yellow-red, straw, mustard, and sandy.

Gray: Pale to dark gray, including silver; can be mixed with other colors or various shades to create sandy pepper, pepper, grizzle, blue-black gray, or silver-fawn.

Lemon: A very pale yellow or wheaten color which is not present at birth (the puppies are born white) but gradually becomes apparent, usually during the first six months of life.

Liver: A reddish brown somewhat the color of cinnamon or bronze; the breed often determines whether "liver", "chocolate", "brown", or "red" is used to describe the color, as in a liver German Shorthaired Pointer or a chocolate Labrador Retriever.

Red: Reminiscent of reddish woods such as cherry or mahogany; also tawny, chestnut, orange, rusty, and red-gold.

Sable: Black-tipped hairs; the background color can be gold, silver, gray, or tan.

Tricolor: Consisting of three colors; usually black, tan, and white or liver, tan, and white; for example, the Smooth Collie or the Sheltie.

Wheaten: Pale yellow or fawn, like the color of ripe wheat

White: Distinct from albino dogs.

Yellow: Yellowish-gold tan, as in a yellow Labrador Retriever.

Dalmatian’s Coat
The Dalmatian's coat is one of the more widely recognized markings.Coat patterns include:

Brindle: A mixture of black with brown, tan, or gold; usually in a "tiger stripe" pattern

Harlequin: "Torn" patches of black on white; only the Great Dane exhibits this pattern

Merle: Marbled coat with darker patches and spots of the specified color; for example, a blue merle is marbled gray and blue with black and sometimes white patches; a red (or liver) merle has deep red or brown on lighter red, often with white or black mixed in.

Particolor: Two-colored coat with the colors appearing in patches in roughly equal quantiles (in breeds where this is an allowed coat color; in breeds where patches of white are considered undesirable, a dog showing even a small patch of white might be classified as a particolor).

Coat Textures
Coat textures vary tremendously, so that some coats make the dogs more cuddly and others make them impervious to cold water. 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 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:

GermanWirehaired Pointer’s Coat
The German Wirehaired Pointer's coat demonstrates a rough texture.

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.

Long-haired: Hair longer than an inch or so.

Short-haired: Hair around an inch or so long.

Corded coat: for example, see Puli

Ears
The Basset Hound's ears are extremely long drop ears.Dogs ears come in a variety of sizes, shapes, lengths, position on the head, and amount and type of droop. Every variation has a term, including:

Bat ear: Erect, broad next to the head and rounded at the tip.

Button ear: A smaller ear where the tip folds forward nearly to the skull, forming a V, such as the Jack Russell Terrier.

Cropped ear: Shaped by cutting; see docking.

Drop ear: An ear that folds and droops close to the head, such as most scent hounds'. Also called a pendant ear.

Natural: Like a wolf's.

Prick ear: Erect and pointed; also called pricked or erect.

Rose ear: A very small drop ear that folds back; typical of many sight hounds and the English Bulldog.

Semiprick ear: A prick ear where the tip just begins to fold forward, such as with the Rough Collie.

Tails
The Basenji's tail is tightly curled.As with ears, tails come in a tremendous variety of shapes, lengths, amount of fur, and tailset (positions). Among them:

Corkscrew: Short and twisted, such as a Pug

Docked: Shortened by surgery or other method, usually two or three days after birth; see docking

Odd: Twisted, but not short. Uncommon. Tibetan Terriers have odd tails.

Saber: Carried in a slight curve like that of a saber

Sickle: Carried out and up in a semicircle like a sickle

Squirrel: Carried high and towards the head, often with the tip curving even further towards the head.

Wheel: Carried up and over the back in a broad curve, resembling a wheel.