Sunbleaching or Sweat?

As a lover of chestnut horses, and a nutritionist, sunbleaching had frustrated me for YEARS!

My gelding Poet, a stunning almost liver chestnut in the spring, would bleach to a homeless looking colour by the end of our hot summers… leaving me wondering if perhaps his mineral balance wasn’t quite right.

That was until one particularly hot summer when Poet and I did an unintentional experiment over our Christmas break… which seemed to show that the sunbleaching that occurs in some horses over summer is a combination of sun and sweat.

Where we live flies can get bad, so my horses have flymasks on during daylight hours. It had been hot (like seriously hot… 40 degrees celcius/100 F plus for weeks at a time) so they sweated a fair bit behind their ears where the strap for the masks sit.

Check out the bleaching pattern on Poet … he had bleached severely where he had sweated around the mask strap!

BUT under the strap, where it wasn’t exposed to any sunlight, he has maintained his coat color. Funky huh!!

He tends to bleach badly around his flanks and on his shoulder where he sweats the most too.

So sweat + sun + a certain color and coated horse = bleaching, even when the diet is well and truly adequate for copper and zinc!

It’s interesting to note that Popcorn, who has an entirely different coat both in colour, length, thickness and even feel doesn’t bleach anywhere, ever.

So specific coats seem to bleach a lot more than others. And our climate obviously contributes significantly too!

Since originally observing this bleaching pattern and writing this blog post years ago, I have added a few more horses to my little herd and notice that some bleach and others don’t!

I have also moved to a property with a LOT more shade and have built a big airy shelter shed that the horses tend to gather under in the late afternoon, so it will be interesting to see if Master Poet bleaches as much this summer!

Here’s what you can do about sunbleaching

If you have a horse that bleaches badly in summer, first make sure their diet is balanced (MyHappy.Horse will put together a balanced diet for you, download the free app and get started!).

AND provide plenty of shade! If coat colour is really important for your horse’s career, rugging with a very light sheet will also help a lot!

Good luck! And if you have any cool photos of bleaching on your horses, we’d love you to share them with us on socials!