Horses exhibit a diverse array of coat colors and distinctive markings. A specialized vocabulary has evolved to describe them.
While most horses remain the same coat color throughout life, some undergo gradual color changes as they age. Most white markings are present at birth, and the underlying skin color of a healthy horse does not change. Certain coat colors are also associated with specific breeds, such as the Friesian, which is almost exclusively black.
The horse (Equus ferus caballus) is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of Equus ferus. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature, Eohippus, into the large single-toed animal of today, originally in North America. Humans began domesticating horses around 4000 BCE in Central Asia, and their domestication is believed to have been widespread by 3000 BCE. Horses in the subspecies caballus are domesticated, although some domesticated populations live in the wild as feral horses. These feral populations are not true wild horses, which are horses that have never been domesticated. There is an extensive, specialized vocabulary used to describe equine-related concepts, covering everything from anatomy to life stages, size, colors, markings, breeds, locomotion, and behavior.
Horses are adapted to run, allowing them to quickly escape predators, and possess a good sense of balance and a strong fight-or-flight response. Related to this need to flee from predators in the wild is an unusual trait: horses are able to sleep both standing up and lying down, with younger horses tending to sleep significantly more than adults. Female horses, called mares, carry their young for approximately 11 months and a young horse, called a foal, can stand and run shortly following birth. Most domesticated horses begin training under a saddle or in a harness between the ages of two and four. They reach full adult development by age five, and have an average lifespan of between 25 and 30 years.
Markings on horses are usually distinctive white areas on an otherwise dark base coat color. Most horses have some markings, and they help to identify the horse as a unique individual. Markings are present at birth and do not change over the course of the horse's life. Most markings have pink skin underneath most of the white hairs, though a few faint markings may occasionally have white hair with no underlying pink skin. Markings may appear to change slightly when a horse grows or sheds its winter coat, however this difference is simply a factor of hair coat length; the underlying pattern does not change.
On a gray horse, markings visible at birth may become hidden as the horse turns white with age, but markings can still be determined by trimming the horse's hair closely, then wetting down the coat to see where there is pink skin and black skin under the hair.
A gray horse (or grey horse) has a coat color characterized by progressive depigmentation of the colored hairs of the coat. Most gray horses have black skin and dark eyes; unlike some equine dilution genes and some other genes that lead to depigmentation, gray does not affect skin or eye color. Gray horses may be born any base color, depending on other color genes present. White hairs begin to appear at or shortly after birth and become progressively more prevalent as the horse ages as white hairs become intermingled with hairs of other colors. Graying can occur at different rates—very quickly on one horse and very slowly on another. As adults, most gray horses eventually become completely white, though some retain intermixed light and dark hairs.
The stages of graying vary widely. Some horses develop a dappled pattern for a period of time, others resemble a roan with more uniform intermixing of light and dark hairs. As they age, some gray horses, particularly those heterozygous for the gray gene, may develop pigmented speckles in addition to a white coat, a pattern colloquially called a "fleabitten gray."
The Lusitano, also known as the Pure Blood Lusitano or PSL (Puro Sangue Lusitano), is a Portuguese horse breed. Horses were known to be present on the Iberian Peninsula as far back as 20,000 BC, and by 800 BC the region was renowned for its war horses. The fame of the horses from Lusitania goes back to the Roman Age, which attributed its speed to the influence of the West wind, who was considered capable of fertilizing the mares. When the Muslims invaded Iberia in 711 AD, they brought Arabian horses with them that were crossed with the native horses, developing a horse that became useful for war, dressage and bull fighting. The Portuguese horse was named the Lusitano, after the word Lusitania, the ancient Roman name for the region that modern Portugal occupies. There are four main breed lineages within the breed today, and characteristics differ slightly between each line.
Lusitanos can be any solid color, although they are generally gray, bay or chestnut. Horses of the Alter Real strain are always brown. Members of the breed are of Baroque type, with convex facial profiles, heavy muscling, intelligent and willing natures, with agile and elevated movement. Originally bred for war, dressage and bullfighting, Lusitanos are still used today in the latter two. They have competed in several Olympics and World Equestrian Games as part of the Portuguese and Spanish dressage teams. They have also made a showing in driving competitions, with a Belgian team of Lusitanos winning multiple international titles.
Chestnut is a hair coat color of horses consisting of a reddish-to-brown coat with a mane and tail the same or lighter in color than the coat. Chestnut is characterized by the absolute absence of true black hairs. It is one of the most common horse coat colors, seen in almost every breed of horse.
Chestnut is a very common coat color but the wide range of shades can cause confusion. The lightest chestnuts may be mistaken for palominos, while the darkest shades can be so dark they appear black. Chestnuts have dark brown eyes and black skin, and typically are some shade of red or reddish brown. The mane, tail, and legs may be lighter or darker than the body coat, but unlike the bay they are never truly black. Like any other color of horse, chestnuts may have pink skin with white hair where there are white markings, and if such white markings include one or both eyes, the eyes may be blue. Chestnut foals may be born with pinkish skin, which darkens shortly afterwards.
The Morgan horse is one of the earliest horse breeds developed in the United States. Tracing back to the foundation sire Figure, later named Justin Morgan after his best-known owner, Morgans served many roles in 19th-century American history, being used as coach horses and for harness racing, as general riding animals, and as cavalry horses during the American Civil War on both sides of the conflict. Morgans have influenced other major American breeds, including the American Quarter Horse, Tennessee Walking Horse and the Standardbred. During the 19th and 20th centuries, they were exported to other countries, including England, where a Morgan stallion influenced the breeding of the Hackney horse. In 1907, the US Department of Agriculture established the US Morgan Horse Farm near Middlebury, Vermont for the purpose of perpetuating and improving the Morgan breed; the farm was later transferred to the University of Vermont. The first breed registry was established in 1909, and since then many organizations in the US, Europe and Oceania have developed. There were estimated to be over 175,000 Morgan horses worldwide in 2005.
The Morgan is a compact, refined breed, generally bay, black or chestnut in color, although they come in many colors, including several variations of pinto. Used in both English and Western disciplines, the breed is known for its versatility. The Morgan is the state animal of Vermont and the state horse of Massachusetts and the state mammal of Rhode Island. Popular children's authors, including Marguerite Henry and Ellen Feld, have portrayed the breed in their books; Henry's Justin Morgan Had a Horse was later made into a Disney movie.
A mottle is a pattern of irregular marks, spots, streaks, blotches or patches of different shades or colours. The term commonly describes the surface of plants or the skin of animals. In plants, mottling usually consists of yellowish spots on plants, and is usually a sign of disease or malnutrition. Many plant viruses cause mottling, including Tobacco vein mottling virus and Bean pod mottle virus.
"Mottling" is sometimes used to describe uneven, discolored patches on the skin of humans as a result of cutaneous ischemia (lowered blood-flow to the surfaces of the skin) or Herpes zoster infections. The medical term for mottled skin is dyschromia. Although not always the case, mottling can occur in a dying patient and commonly indicates that the end of life is near. Mottling usually occurs in the extremities (lower first) and progresses up as cardiac function declines and circulation throughout the body is poor. In animals, mottling may be a sign of disease, but may also be a hereditary trait, as seen with the champagne and leopard complex genes in horses.