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Summer Sun Bleaching

Updated: Jul 5, 2020

We have always loved and owned dark colored horses.  Lots of black and dark bay horses can turn brown or reddish during the summer from sun bleaching.  Most people think that sun bleaching is unavoidable, but it is generally a sign of trace mineral imbalance in the diet.  Those of us with dark colored horses are lucky to have this visible clue that our mineral balance is off, but since all horses regardless of their coat color are prone to mineral imbalance on a domestic diet, it is equally important for all horses to be fed in ways which foster a more correct balance of trace minerals.

Good coat and hoof quality, as well as many other vital functions, are

dependent upon adequate copper and zinc in the diet. Equine diets are naturally high in iron and low in copper and zinc and these three minerals compete for the same receptors in the body, so the higher the iron in the diet the less copper and zinc will be absorbed. Copper and zinc are both involved in the production of melanin, the pigment which gives color to the coat and protects the coat from UV radiation from the sun, so if a horse is relatively too low in copper and zinc the coat will suffer from sun damage in the summer.

We have tested our hays and found them all to be very high in iron compared to their amount of copper and zinc and we have also checked our horses’ blood for iron levels and found our older horses were suffering from iron overload which not only blocks the absorption of copper and zinc, it also leads to inflammation and a host of other health problems. Horses have no mechanism for excreting excess iron from the body so it is best to choose foods and supplements without added iron and to add a mineral supplement which provides copper and zinc without any iron in the mix.  Most hoof supplements fit the bill. We use a product called California Trace but there are any number on the market.

All horses can benefit from copper and zinc supplementation, but the effects are rapidly visible in horses with dark or black coats which show damage from sun bleaching—when you see the coat quality and color improving you’ll know that the horse’s whole system is getting healthier as well!

Mineral balancing also has a huge effect on hoof health by the way!

Miranda Fior of


Author Bio:

Miranda started trimming in 2002 to help her own laminitic mare, and has been trimming professionally since 2004. She is a founding member of the PHCP (Progressive Hoof Care Practitioners) and has a special interest in laminitis/founder rehabilitation, and equine nutrition.


Before and after mineral supplementation

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