Horses are susceptible to sunburn during the summer months, particularly horses with lighter colored skin and white haircoat. The severity of sunburn depends on degree of exposure and the skin sensitivity of the horse. Certain regions of the world have a higher UV index than others, and horses living in these areas that are prone to sunburn, should be protected.

Since sunburns often can appear very similar to photosensitization, it is important to differentiate between the two conditions, as photosensitization is often indicative of liver damage. Sunburned horses usually are only affected on the face (particularly the muzzle) and are usually horses with a pink muzzle. When horses are affected by photosensitization, all white areas of the body will be affected.