To see a horse in your dream, represents a strong, physical energy. You need to tame the wild forces.

The dream may imply that you have been horsing around. Or perhaps you need to be less arrogant and "get off your high horse".

To see a black or dark horse in your dream, signifies mystery, wildness, and the unknown. You may be taking a chance or gamble at some unknown area.

It may even represent occult forces. If the horse is white, then it signifies purity, prosperity and good fortunes.

To see a dead horse in your dream, indicates that something in your life that initially offered you strength is now gone. This may refer to a relationship or situation.

To see a herd of wild horses in your dream, signifies a sense of freedom and lack of responsibilities/duties. Perhaps it may also indicate your uncontrolled emotions.

To dream that you are riding a horse, denotes that you will achieve success through underhanded means. You lack integrity. If you are riding a horse that is out of control, signifies that you are being carried away by your passions.

To see an armored or medieval horse in your dream, refers to your fierceness, aggression, power and/or rigidity. You may be seen as too confrontational.
Alternatively, you may be trying to protect yourself from unconscious material or sexual desires that are emerging.