How Your Horse Got His Color (And Why You Should Care)

A horse’s coat color genetics are important not just for aesthetic reasons or breed registry inclusion; they can also have serious health implications.

As a kid trotting around the 4-H show ring, I was convinced that judges favored my best friend’s horse—a flashy dapple-gray Thoroughbred with black legs and a dark mane and tail—over my undistinguished (but much-loved) liver chestnut. The fact that my friend rode well and that gorgeous “Penny” was also a great mover with picture-perfect jumping form probably had something to do with their success, but that didn’t stop me from wishing and hoping that my family’s soon-to-foal mare, a coppery-red chestnut, would drop a stunning steely gray baby with black points.

Well, it didn’t happen. Out popped a colt with (surprise!) a coppery-red coat matching that of his sire and dam. In hindsight, the odds were stacked against me, as breeding a chestnut to another chestnut will inevitably yield more of the same. (And if it doesn’t, it’s time to do a paternity test!) But that’s one of the few givens in the world of equine coat colors, an equation that’s only solved by digging deep into the genes that make up equine DNA.