Mystery: why does Biz’s dun mustang appear to be turning gray?
You know those scenes towards the end of mystery movies when all the clues come together montage-style, usually backed by some uber-dramatic music, and by seeing them side by side you’re able to determine the murderer? I recently had one of those scenes in my head, but instead of pointing towards the perpetrator of a murder, the clues were pointing towards a potentially interesting fact about my little horse.
Clue #1 occurred nearly two years ago when a mysterious bump appeared on Helix’s neck. Being the overprotective mother that I am, I had the vet out to look at him immediately. “It looks to be a melanoma,” he said, “but your horse is very young and the wrong color for this to be normal.” So to be safe, the vet removed the lump, taking a very large margin to be sure he got all of the potentially cancerous cells. Analysis of the excised tissue showed it to be benign, luckily, but officially made me paranoid about the presence of unknown lumps on my horse.
Clue #2: Just like any adoring mother out there, I frequently share pictures of my “children” on social media (and FYI Mom, Dad, and in-laws, they DO count as real children even though they aren’t technically human). One day in August after posting this picture…
… a friend commented “Wow! His color is really lightening up, huh?” At the time I assumed the lighting had just made him look washed out in the picture.
Clue #3: Fast-forward to January when I received a photo from Helix’s “babysitter” while I was in New Hampshire visiting family, telling me that aside from having an extraordinary talent for taking out his braids, he was being a good boy. He looked so handsome and grown up in the picture that I felt compelled to share it in a Kiger mustang Facebook group.
I got lots of responses along the lines of “handsome!’ and “cute!” which satisfied the dopamine feedback loop we all crave from social media. My brain was satisfied that people liked me… or at least “liked” me.
Then one person asked “Is he turning gray? His face and tail look like they are turning gray.” Again, I brushed it off thinking it must be a lighting thing, but when I got to the barn that day, I noticed his face was pretty gray, and he had little gray patches on the top of his hind quarters and on his back. I started going through all of his baby pictures to compare his color then to his color now, and that’s when all the clues came rushing into my head montage-style. My first thought was “is this even possible? Can a dun horse also be gray (not grulla, but actually gray)?” “Is my little dun horse actually a gray?” I asked myself.
After doing a little research and consulting with some of my very smart friends, I was able to determine that the gray gene is dominant and can be paired with any coat color, but how to know for sure?! I could look into the colors of his sire and dam to see if he had a gray parent, but I have no clue who the sire is. I can wait it out and see what color he winds up being, but that could take years and seems incredibly inefficient.
I know there is a better way: we have the power! What we can learn about living organisms from their DNA is pretty incredible these days. In fact, I spend a lot of my time looking at plant DNA, so I’m quite familiar with the options molecular biology provides in this situation.
The choice seems pretty obvious. While my horse’s color really isn’t that important in the long run, I’m curious, gosh darnit! I ordered DNA testing kits from UC Davis, and will be sending in a sample to test for the presence of the gray gene. Stick around and check my column again when I get the results!
Next week we will talk about how genes work and how a gene is translated into pigment in your horse’s coat. Until then, remember, a good horse is never a bad color.
Biz is the author of Horse Nation’s “Back to Basics” series, which follow the journey of a “somewhat ordinary” horse and rider pair as they strive for greatness. Catch up on her past columns by clicking the #BACK TO BASICS at the top of the page.
Biz Stamm is a part-time seed scientist and full-time trainer/riding instructor specializing in starting young horses for sport horse disciplines. She brings the analytical mind she developed while working in a lab to her riding and teaching, emphasizing a thorough understanding of how the horse’s body works. She currently owns two horses: the Kalvin Cycle (Kalvin), a 9-year-old half-Arabian gelding, and DB’s Alpha Helix (Helix), a 4-year-old Kiger mustang gelding. While she is currently pursuing competitive goals, her main goal is to enjoy her horses, and for her horses to enjoy her.