horse

The horse (Equus caballus) is a odd-toed ungulate mammal, one of eight living species of the family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today. Humans began to domesticate horses around 4500 BC, with domestication of the horse believed to have been widespread by 3000 BC. By 2000 BC the use of domesticated horses had spread throughout the Eurasian continent. While most horses today are domesticated and live in close proximity to humans, there are still endangered populations of the Przewalski's horse, the only remaining true wild horse that has no domesticated ancestors, as well as more common feral horses, such as the American Mustang, which live in the wild but are descended from domesticated ancestors.
Horses are described with a large number of specific terms that describe everything from their anatomy to their life stages, colors, white markings, breeds, locomotion and behavior. They have a wide range of sizes, and are anatomically designed as a herbivore with the ability to use speed to escape predators. Horses have a well-developed sense of balance and a strong fight-or-flight instinct. Related to this need to flee from predators in the wild is a unique trait: horses are able to sleep both standing up and laying down. 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 horses begin training under saddle or in harness between the ages of two and four, reaching full adult development by age five, and have an average lifespan of between 25 and 30 years.
Horse breeds are loosely divided into three categories based on general temperament: spirited "hot bloods" with speed and endurance; "cold bloods," such as draft horses and some ponies, suitable for slow, heavy work; and "warmbloods," developed from crosses between hot bloods and cold bloods, often creating specially-developed breeds, particularly in Europe. There are over 300 breeds of horses in the world today, developed for many different uses. Some regions in the world are known for a specialty in development of a particular breed or set of breeds, such as harness horses in Russia or draft and pony breeds in Great Britain.
Horses and humans have extensive interactions today, not only in a wide variety of sports competitions and non-competitive recreational pursuits, but also working activities such as police, draft work, entertainment, assisted learning and therapy, and modern warfare. Many products are also made from horse meat, milk, hide, hair and bone, as well as pharmaceuticals made from the urine of pregnant mares.
Domesticated horses require specialized care to stay healthy, including proper provision of food, water and shelter, but also additional care from specialists such as veterinarians and horseshoers, or farriers. There is a wide variety of riding and driving techniques for managing horses, using many different styles of equipment and methods of control.
Horse anatomy is described by a large number of horse specific terms, as illustrated by the chart to the right. Specific terms also describe horses of various ages, colors and breeds.
AgeDepending on breed, management and environment, the domestic horse today has a life expectancy of 25 to 30 years. It is uncommon, but a few horses live into their 40s, and, occasionally, beyond. The oldest verifiable record was "Old Billy," a horse that lived in the 19th century to the age of 62.[1] In modern times, Sugar Puff, who had been listed in the Guinness Book of World Records as the world's oldest then-living pony, died at age 56.[2]
Regardless of a horse's actual birthdate, for most competition purposes, horses are considered a year older on January 1 of each year in the northern hemisphere[3][4] and August 1 in the southern hemisphere.[5] The exception is endurance riding, where the minimum age to compete is based on the horse's actual calendar age.[6] A very rough estimate of a horse's age can be made from looking at its teeth.[4]
The following terminology is used to describe horses of various ages:
Foal: a horse of either sex less than one year old. A nursing foal is sometimes called a suckling and a foal that has been weaned is called a weanling. Most domesticated foals are weaned at 5 to 7 months of age, although foals can be weaned at 4 months with no adverse effects.[8] Yearling: a horse of either sex that is between one and two years old.Colt: a male horse under the age of four.A common terminology error is to call any young horse a "colt," when the term actually only refers to young male horses. Filly: a female horse under the age of four. Mare: a female horse four years old and older. Stallion: a non-castrated male horse four years old and older. Some people, particularly in the UK, refer to a stallion as a "horse."[13] A Ridgling or "Rig" is a stallion which has an undescended testicle. If both testicles are not descended, the horse may appear to be a gelding, but will still behave like a stallion.[14] Gelding: a castrated male horse of any age, though for convenience sake, many people also refer to a young gelding under the age of four as a "colt." In horse racing, the definitions of colt, filly, mare, and stallion or horse may differ from those given above. In the United Kingdom, Thoroughbred horse racing defines a colt as a male horse less than five years old, and a filly as a female horse less than five years old.[15] In the USA, both Thoroughbred racing and harness racing defines colts and fillies as four years old and younger.[16]
SizeThe English-speaking world measures the height of horses in hands, abbreviated "h" or "hh," for "hands high," and is measured at the highest point of an animal's withers, where the neck meets the back. One hand is 4 inches (10 cm). Intermediate heights are defined by hands and inches, rounding to the lower measurement in hands, followed by a decimal point and the number of additional inches between 1 and 3. Thus a horse described as "15.2 hh," is 15 hands, 2 inches, or 62 inches (160 cm) in height