Would you like to know what color your horse is? Do you have questions about the color of your foal? You've come to the right place.
White horses have a special place in the human imagination. Held sacred by many ancient cultures, they still bring to mind images of Pegasus and unicorns. The reality is a bit more mundane although the coloring is still striking. Most of the "white" horses seen in movies and TV are not in fact not white but completely grayed out or light cremellos or perlinos.
White patterns in horses are known to cause bright blue eyes. The white pattern most often associated with blue eyes in horses is the splashed white pattern. KIT gene mutations (including Dominant White, Sabino, and Tobiano) are not as frequency associated with blue eyes but why? The reason lies with gene function and the distribution of pigment during embryonic development.
The brindle color pattern does not often occur in horses. The only mutation in horses that reliably produces a brindle coat color is now known to be associated with skin and other health problems and to be lethal in male foals. All other known brindles in horses are the result of chimerism or other mechanisms that do not reliably reproduce. Chimerism occurs when twins fuse very early in development.
The past several days have been very exciting in the world of Equine Color Genetics. The results from the first round of W20 testing has started to filter into facebook and the results are very popular. However, this has caused a problem. More than once over the past several days, I have found myself explaining why this white pattern (and all white patterns at the KIT locus) should know be referred to as “White Spotting” rather than Dominant White or Sabino.
Then it dawned on me...Why can’t we just call them all Sabino? These white patterns, phenotypically, look like Sabino. Who cares if they are inherited as an Dominant, incomplete dominant or recessive for that matter.
Most of us are familiar with gray horses. Horses that are born a solid color but then slowly (or sometimes not so slowly) turn white as they age. We've seen them as the majestic “white” Lipizzaners and the “white” horses in many Hollywood productions including the Lord of the Rings movies. Recently however, it has been discovered that not all gray horses turn white as they age. In fact, some don't look “gray” at all even when at an advanced age. Often these horses have been labeled as Rabicano or even roan but at least one of the more famous has been confirmed to carry the Gray mutation. This horse is Comico IV.