The ancestors of today’s horse breeds are wild horses which evolved over many millennia in habitats subject to extreme conditions (climate, weather, predators, terrain) and scarce food supplies. This has resulted in highly specialised forms of anatomy, physiology and behaviour. Domestication has had little effect on these traits; horses are still herd animals exhibiting highly developed social structures and pronounced flight behaviour. Their physiology is based on a lifestyle as a prey animal, where a large part of the day is spent exercising (foraging for food) and fast reactions can mean the difference between life and death.