Sunburn or Photosensitivity in Horses

Especially in the summer season humans and animals alike can experience sunburn. Despite our best efforts to apply plenty of sunscreen and stay in the shade this condition affects many of us from time to time. Horses are no different but when it comes to the equine world sunburn is usually most severe on the nose. Your horse may also experience burns on its back face ear tips and white areas on the legs. Horses with white coats whether entirely white or in patches on the body are more susceptible to burns.

Some may experience a condition with similar symptoms called photosensitivity caused by the ingestion of certain plants 1 Sunburn usually resolves on its own but a variety of treatment options can help ease your horses symptoms.
What Is Sunburn?
Sunburn occurs because of overexposure to ultraviolet UV light which typically causes symptoms like redness inflammation and pain. Horses with unpigmented patches on their bodies are more likely to experience sunburn than those with darker coats noses and legs. Lesions from burns typically affect parts of the body that come into consistent contact with direct sunlight like the nose and face 1
Symptoms of Sunburn in Horses
Horses experience similar symptoms of sunburn to those seen in humans. Like the red irritated areas on your own skin during the summer months you may observe the following signs of sunburn on your horse
Symptoms
Red skin
Inflammation
Blistering and peeling
Pain
Red skin and inflammation are both common signs of sunburn although horses may also experience blisters peeling scabs and cracked skin in more severe cases 1 This is usually limited to the face and nose but horses that are thincoated or have pink skin may also become sunburned on their backs. Most commonly horses with white or pink noses like grays or pintos experience sunburn 2 In some cases burns

can also occur along the protruding areas of the face ear tips and white leg markings just as human noses ears shoulders and collarbones get burned from direct exposure to the sun.
Causes of Sunburn
While exposure to the sun during the hottest parts of the day may be enough to cause a sunburn on your horse photosensitization can also lead to burns when your horse ingests certain plants. The following causes of sunburn and photosensitivity may occur
Overexposure to the sun Ultraviolet light from the sun causes sunburn on humans and many animals when overexposed. If your horse enjoys spending time in the pasture or other areas with direct light its best to limit these outings to times of the day when the sun isnt as strong 2
Photosensitization caused by plants There are a number of plants that can cause photosensitivity in horses. St. Johns Wort affects horses and cattle with this condition. Other plants like buckwheat and ground elder also known as snowinthemountain can have this effect. One species alsike clover can cause photosensitivity as well as liver failure gastric problems and neurological disorders. This is called secondary photosensitization and byproducts from chlorophyll in some green plants are the reason that exposure may cause liver problems 1
Topical treatments and medications Some grooming sprays or fly sprays may exacerbate a sunburn. Photosensitivity may also be caused by some medications so owners should consult their equine veterinarians about safe choices for horses in direct sunlight.
Diagnosing Sunburn in Horses
If your horse experiences a normal sunburn that is not linked to photosensitization your veterinarian can diagnose the condition during a standard physical exam. However the signs of photosensitization are similar to those of standard sunburns and a veterinarian should be consulted to determine the underlying cause of your horses symptoms. Photosensitization may indicate the presence