Horse

The horse (Equus ferus caballus) is a domesticated, one-toed, hoofed mammal. Horses come in more than 300 breeds worldwide, developed for a wide range of uses.

Size varies by breed. Light riding horses usually stand 14 to 16 hands (142 to 163 cm) and weigh 380 to 550 kg. Larger riding horses often reach 17 hands, and heavy draught horses can be as tall as 18 hands. Height is measured at the withers, and one hand equals 4 inches. Ponies are the same animal as horses; the traditional dividing line is 14.2 hands, though breed and build matter too.

Horses are kept for sport, recreation, and working roles such as police work, agriculture, entertainment and therapy. In the UK, some semi-feral herds, such as those on Dartmoor and in the New Forest, are privately owned but spend long periods living in wild conditions.

The horse evolved over 45 to 55 million years from a small multi-toed creature, first in North America. The side toes gradually shrank, leaving only small splint bones on the lower leg. The modern Equus had appeared by about 5 million years ago.

People began domesticating horses around 4000 BCE. Horses from the Botai culture of Central Asia turned out not to be the ancestors of modern horses. Modern domestic horses instead point to the Western Eurasian steppes, in the lower Volga-Don region. By 3000 BCE horses were fully domesticated, and from about 2000 BCE they spread rapidly across Eurasia.

Horses were used in warfare, which led to many riding and driving techniques. Selective breeding began soon after domestication, and the Thoroughbred stud book began in 1791. Truly wild horses are very rare today; Przewalski's horse is the only wild subspecies left, and most so-called wild horses are feral.

Horses are prey animals with a strong fight-or-flight response. They usually startle and flee, but they are also curious and may pause to work out what frightened them. They are herd animals with a clear rank order, usually led by a mare, and they can form bonds with other horses and with other animals, including humans.

Breeds are grouped by temperament. Hot-bloods, such as the Thoroughbred and Arabian, are spirited and quick to learn. Cold-bloods, such as most draught horses, are calm and patient and are sometimes nicknamed gentle giants. Warmbloods are crosses of the two. Ponies may have calmer temperaments than horses, and may also have a high level of intelligence.

Horses communicate by nickering, whinnying, mutual grooming and body language. They can sleep standing or lying down, in many short rests, and sleep better in groups. Horses confined with too little company, exercise or stimulation may develop stable vices such as wood chewing, wall kicking and weaving.

The average lifespan is 25 to 30 years, depending on breed, management and environment. A few live into their 40s. The oldest verified horse, Old Billy, reached 62.

Horses cannot vomit, so digestion problems can quickly lead to colic, a leading cause of death. A study of racehorses found higher rates of gastric ulcers in those stabled with talk radio or any radio playing.

Horses occasionally eat toxic amounts of poisonous plants even when there is plenty of healthy food. The feet and legs are vital, as the old saying goes: no foot, no horse. The hoof grows continually, and a horse has no muscles in its legs below the knees and hocks. Horses that are never able to lie down can become sleep-deprived and, rarely, suddenly collapse. Horses may also suffer from narcolepsy.

This is general awareness only, not veterinary advice. Always consult a vet about your pet's health.

How long do horses live?

Most live 25 to 30 years. A few reach their 40s, and the oldest verified horse lived to 62.

What is the difference between a horse and a pony?

They are the same animal. A pony is usually one under 14.2 hands (147 cm), but build, coat and temperament count too. Some small breeds, such as the Falabella, are classed as miniature horses rather than ponies.

Do horses sleep standing up?

Yes, they can sleep both standing and lying down. A special arrangement in the legs lets them doze without collapsing. They do need to lie down for a while every few days to reach REM sleep.

At what age are horses ridden?

Most are started under saddle or in harness between two and four years old. They reach full adult development by about five, and the skeleton keeps developing until around six.

Is a white horse really white?

Usually not. A horse that looks white is most often a middle-aged or older grey, as greys are born darker and lighten with age. There are no true albino horses.

Can horses be kept alone?

Horses are social herd animals, and many become difficult to manage if isolated. With training, they can learn to accept a human as a companion.

A horse has about 205 bones and no collarbone. What is called the knee is really the equivalent of a human wrist.

Horses have eyes on the sides of their heads, giving a range of vision of more than 350 degrees. Each ear can rotate up to 180 degrees.

A foal can stand and run shortly after birth. Mares carry their young for about 11 months.

The largest horse on record was probably a Shire named Mammoth, born in 1848, who stood 21.2 and a quarter hands. The smallest, Thumbelina, was only 43 cm tall.

A 2013 UK study found stabled horses were calmest in quiet or while listening to country or classical music.

Horses walk at about 6.4 km/h, and the fastest recorded sprint was 70.76 km/h.