With the Irish celebration of St. Patrick's Day  just a few days from now, here is one of the many Celtic legends that include the horse.  Thank to "Symbolic Horse Education Resources" for the information.

Origins of horse whispering can be seen in Celtic belief and in the more recent “horseman’s word”, a magic word which if uttered gave one power over horses, and with claim going back to Britain.  This concept reached its culmination at the latter end of the 19th century with the formation of the “Secret Society of the Horseman’s Word”, prevalent down the north-eastern side of Britain.  The word was such a closely guarded secret that if it existed it was never divulged, and the society’s rituals also remain vague (only passed on through esoteric oral tradition), though it is still rumored to exist. 

Modern horse owners still tend to the belief that there may be a magical word that will give power over horses, and observe that some people do indeed appear to have better control over horses than others without apparently doing anything different.

Other Celtic horse legends include:

• The horse was introduced into Ireland by the greatest of their native gods, Lugh, the sun god. 
• Mannanan Mac Lir, the god of the sea, had a magical horse that could travel over land or sea.
• Cuchulainn had two magnificent chariot horses which came to him from lakes.
• Many riders emerged from the Otherworld astride a magnificent white horse.
• Horses had the ability to see ghosts and refused to pass a haunted spot.
• The “fíorláir” or ‘true mare’ – the seventh consecutive filly foal born to a dam, which was safe from all evil and its rider safe from all harm.
• Celtic priests considered horses to understand the will of the gods more clearly than man and so could reveal divine secrets.