A few  beliefs about the horse from various cultures:

Often a common symbol of a soul journey to learn the great secrets of life, death and magic
 

The horse was often associated with fire and water as live-giving, yet dangerous forces
 

In Scotland: the ""kelpi" or water spirit was embodied in the sea or as a  white horse

 whose mane was like the foaming crests of the waves
 

In Greece: the winged horse Pegasus was a symbol of light and strength harnessed by reason

Symbol for youth, strength, sexuality and masculinity