The theme of this thesis is the Equidae horse family. The only living genus is Equus. It is divided into seven species which are: the wild horse, Asiatic wild donkey, African donkey, kiang, grevy’s zebra, mountain zebra and plains zebra.Horses are generally large animals with a relatively large head and long extremities. The size and weight vary. Their coat is thick and commonly short, and most breeds have longer hair (a mane) on their neck, poll and tail.The colors of their coat vary and fall into breed characteristics, so brown and grey colors are considered traits of the primitive breeds, whereas zebras are recognizable for their stripes all along their bodies.The three basic colors are: chestnut, the basis of which is a yellowish-ginger color as in tail and mane, the black whose coat, mane and tail are black, and the bay, whose basic color is brownish-ginger, and the mane, tail and legs can be black.Apart from color, horses can have different characteristics so we differentiate between white markings on the head and legs and black markings. Horses are polyestrous animals. They commonly mate during spring due to the fact that their sexual grill is the most expressed.A horse’s pregnancy lasts between 330 and 410 days, the longest lasting one being that of the grévy's zebra, and the shortest one is that of the domesticated horse. They usually give birth to one foal. Members of the horse family can cross-breed. The common life expectancy of a horse is between 20 and 30 years. The horse is a herbivore. Daily, it drinks around 40 liters of water. The biggest part of their digestion occurs is the intestines. Because of the enormous quantity of plant-based food it consumes, the horses have very long intestines. Their stomach is, unlike the ruminants, built with only one chamber. Food fermentation takes place in the enormous appendix and the long colon.