Q. Earlier this year I purchased a mare who had a dull coat and needed to gain weight. After several months she now looks amazing and has developed beautiful dapples. I’ve always heard dapples are related to diet, specifically fat. However, I don’t feed her that differently than my other horses, and they don’t have dapples. Why do some horses get dapples and some don’t?
A. Dapples on nongray horses are interesting. These irregular spots where the coat appears as a slightly different shade are seen on some horses but not others. Horses might only get them at certain times of the year. In the winter some horses have them, but when you clip them the dapples disappear. And as you have observed, dapples often appear to be condition-dependent. Traditionally, they are thought to be a sign of good health, so that would somewhat explain the condition connection.
While there does seem to be a nutritional component to horses having dapples, there is far more to it than that. As with all coat colors, dapples are, in part, controlled by genetics. Dapples result from variation in the patterns of red vs. black pigment along the hair shaft, rather than changes in pigmentation across the skin. This is why they disappear when you clip a dappled horse. Genes that respond to changes in nutrition control the deposition of black pigment along the length of the hair. Chestnut horses and those with colors in the chestnut family lack the ability to create eumelanin and, therefore, do not display strongly pigmented dapples. However, they may still have the variant responsible for dapples, which they can pass to their offspring.
You will need to work to create the optimal conditions for dapples to occur. This is where condition, management, and nutrition come in.
Your best chance of having dapples occur is to ensure all the horse’s dietary needs are met, his diet is balanced, and his coat is well-looked-after. Start with your forage. Feed the best-quality forage you can, and make sure your horse is getting enough. Stomach ulcers can wreak havoc on coat quality, so feeding plenty of forage to keep the digestive tract happy is an important component.
Make sure your horse’s diet is providing adequate quality protein and the amino acids lysine and methionine, which are the most limiting. Some old-time horse managers swear that protein is crucial for dapples and that it will put bloom on the coat. Fatty acids will help improve shine, too, so consider feeding a small amount of oil or high-fat seed meals such as flax. However, stay away from oils high in omega-6 fatty acids in favor of those high in omega-3 fatty acids, which might help reduce itching and improve skin quality.
Trace mineral levels should also meet requirements. For instance, zinc and copper can be low in forage-based diets or when commercial feeds are fed incorrectly. Both these trace minerals are needed for melanin production, so they directly impact coat color. Seek help from a nutrition professional if you are unsure whether the existing diet is meeting these needs.
Beyond diet, grooming practices are vitally important for coat quality. So often we are in a rush when we get to the barn and take barely a minute to flick our horse’s coat off before tacking up, but try spending at least 10 to 15 minutes grooming your horse at least several times a week, and you will see the benefits. Start with a rubber curry to stir up all the dirt, and then remove it with a stiff brush. In the summer, or if your horse is clipped, finish off with a soft brush. Going through these stages brings the natural oils to the coat’s surface, creating an amazing natural shine that no amount of bathing can produce. Clean your brushes frequently so you aren’t just putting the dirt back on the horse. Grooming this way has the added advantage of raising your heart rate and warming you up to ride.
If you take all these steps and still do not see dapples, don’t be disappointed. Genetics might not be in your favor, but your horse will still look stunning. And who doesn’t love a horse with a mirrorlike coat and show ring bloom?