Sunburn and Photosensitization in Horses


The summer sun probably has equestrians reaching for the sunscreen as we head outdoors to ride and care for our horses. Those with fair skin especially realize the importance of applying that SPF. However, have you considered humans are not the only ones susceptible to sunburn this summer?

Although not the same conditions, sunburn and photosensitivity can be difficult to distinguish in your horse this summer.  Photosensitization is more serious and occurs when your horse’s skin becomes overly sensitive to the ultraviolet light (UV) from the sun.  The American Association of Equine Practitioners’ (AAEP) website states photosensitization “is different from sunburn in that it often affects both pigmented and nonpigmented areas of the body.”  You may notice a horse suffering from photosensitization developing redness, hives, or even scaly skin lesions- even on a darker skinned equine.  These photosensitive horses will then rub or scratch these exposed areas of skin, such as the muzzle, ears, and even eyelids in an attempt to satisfy the itch.  If the integrity of the skin is compromised, your horse is now at risk for infection as the open skin entices flies to the site.

Sunburn is the same in horses as in humans and is characterized by redness and inflammation.  Also like humans, sunburn can lead to peeling skin in equines and even blistering if severe.  Pain is associated with equine sunburn as well.  Equines, specifically those with light-colored coats, like Paints and Pintos, Appaloosas, or grays and cremellos, or even light skin, such as horses with bald faces or a white blaze are prone to sunburn.

If you are concerned about your horse becoming sunburned as it grazes this summer, treat it as you would yourself.  The best way to avoid a sunburn is to avoid the sun itself.  If possible, consider keeping your horse stalled during the day and turned out at night.  If that’s not a feasible solution, you can at least try to avoid the part of the day when the sun’s UV light is most powerful, between 10 AM and 2 PM.  Just like humans, once your horse has a sunburn it’s best to avoid more direct sun exposure until the sunburned area has had time to heal.

Going along with the strategy of prevention, sunscreen is another option if keeping your horse stalled is not.  As always, consult with your veterinarian first, but applying a high-SPF sunscreen to the muzzle and any white markings on your horse will ensure decreased UV light exposure.  Just like in humans, sunscreen will need to be reapplied to your horse frequently, as directed on the product.  Mineral sunscreens containing zinc may be most effective in horses as they hold up well and can also help heal skin irritation.  To protect delicate areas, such as around the eyes, consider a full-face fly mask; many of these now come with UV protection.  Remember to remove fly masks daily and check for any areas of skin irritation or discomfort.

If photosensitization is diagnosed by your vet, stalling during the day becomes more of a requirement.  Because this condition is more severe and can cause death of skin tissue, your vet may recommend corticosteroid injections along with other therapies to treat it.


Alicia Johnson

Alicia is a Writer and Editorial Coordinator for the Horse Review. She has two wonderful children, Mason and Madison. Her and her family live an active lifestyle and love being outdoors. Alicia has been a horse lover for as long as she can remember, she didn't become a horse owner until she was an adult. Now, her daughter, Madison, has grown to love horses and it is a passion they share together.

icon Subscribe

to Our Newsletter