Horses are mammals in the same family as zebras, mules, and donkeys. Pigs generally have 44 teeth, including two enlarged canines in each jaw that grow upward and outward to form tusks. Cows moo' to each other fairly frequently allowing them to maintain contact even when they cannot see each other. Cows have 300 degree panoramic vision, much more than humans. Their only blind spot is directly behind them.
Albino horses are the only true white horses.
All white horses descended from Old King, an albino horse whose offspring were always born white, regardless of the mare's color. That evolving species died out, but not before its descendants crossed the land bridge between North America and Asia. Once there it evolved over 50 million years to become the horse we know today. It was the Romans that introduced the horse in sport, bringing us the chariot races. During this time, many religions believed that animals were Gods and there were some horses that were given mythical properties, like the winged Pegasus and the horned unicorn.