From references in Indian literature, there can be little doubt that the horse made a profound impression on ancient India. Although it is likely that the uses of horses were widely known, there is a strong possibility that the new skills in horse breeding and management, and chariot driving, entered India with other aspects of Aryan culture. The effect appears to have been limited, however, as Indians did not gain a reputation for breeding or military use of horses as the Arabs and Mongols did later nor did they seem to take to horsemanship as readily as the North American Indians or the Australian aborigines. This is reflected in association between horses and religion in India which is fitful and sporadic.
As the fleetest form of mobile power they were understandably connected with the motion of some gods and thus inevitably with the path of the sun and therefore with sun-gods. Many aspects of solar deities (e.g. Surya and Ashvins) are to do with horses.
According to Hindu mythology, the tenth incarnation of Vishnu, the horse-god Kalkin, will come at the end of the present kali-yuga when moral excellence no longer exists, the rule of law has disappeared and all is darkness. In some texts, he is described as a riding horse holding a flaming sword, in some as four-armed holding a sword, conch-shell, wheel and an arrow, and in others a human having the head of a horse and holding attributes as above. — Hindu Gods and Goddesses