Spotted horses are magical.

Grey horses and horses with four white socks are unlucky.

Horses have been sacred animals in Indo_European cultures from very early times, and it is easy to see why; their great importance in farming, travel and warfare would make them extraordinarily important. The Celtic goddess Epona presided over horses, and the Norse Odin was said to ride through the heavens on an eight-footed white horse. Horses were used as valuable sacrifices by many ancient peoples, including the Romans, and their bones were concealed in the walls of houses, or horse skulls placed on the gables of houses, as a protection.
Source: Vanessa's Pagan Place Folklore Page

Inhaling a horses breath - cure for whooping cough
Source: oldsuperstitions.com

In some places it is lucky to meet a white horse; in others, unlucky; either way, tradition states that upon meeting a white horse one should spit and make a wish, or cross one's fingers until a dog is seen. In many places it is lucky to lead a horse through the house; this belief may stem from the association of horses with fertility and crops, which has lasted in form of hobby-horses which were originally part of Beltane (May Day) revels.
Source: Vanessa's Pagan Place Folklore Page

It was once thought that whooping-cough could be cured by going to the stables and inhaling the breath of a horse; being breathed upon by a piebald horse, or riding upon its back, was another supposed cure. Horse-hairs, chopped very finely and fed to a child in bread and butter, were thought to be a certain cure for worms, and the horse-spurs (callouses which appear on the sides of a horse's leg) were believed in the eighteenth century to be a cure for cancer if dried, ground and drunk frequently with new milk.
Source: Vanessa's Pagan Place Folklore Page

Horseshoes are considered lucky for their healing powers (cures hiccups) and for their protective influence (specifically against witches). It resembles the crescent moon and is thought to protect against the evil eye. Similar-shaped charms were used among the Chaldeans and the Egyptians. Related to animal worship, it approaches the form of a serpent biting its own tail-a universal symbol of eternity. There is a time-honored belief in the magical power of iron. Blacksmiths were often identified as sorcerers and the efficacy of fire as a bane to demons supported this idea.

A horseshoe, hung above the doorway, will bring good luck to a home. In most of Europe protective horseshoes are placed in a downward facing position, but in some parts of Ireland and Britain people believe that the shoes must be turned upward or "the luck will run out."
Source: Old Wives Tales

A horseshoe hung in the bedroom will keep nightmares away.
Source: Old Wives Tales

The deeper the ladybird's color, the better luck it brings. The number of spots on its back are also important. The more spots...the better the luck!

If a young girl catches a ladybug and then releases it, the direction in which it flies away will be the direction from which her future husband will come.