Sunburn & Photosensitivity: Too Much of a Good Thing

with plant toxins circulating in capillaries near the skins surface.
Ingestion of other plants as well as some molds and mycotoxins can cause liver damage one sign of which is increased skin reaction to sunlight this is known as secondary sensitization.
When only a few plants are present they may be removed by hand or by selective spraying.
If grazing areas are heavily infested with these plants complete renovation of the pasture may be the only way to remove undesirable vegetation.
Among the other plants that cause photosensitization are St. Johns Wort bishops weed spring parsley and wild buckwheat.
Resources
Agricultural agents have the knowledge to identify dangerous plants in pastures or in hay. These experts can also advise on the most effective way to rid fields of unwanted vegetation.
Tack shops and equine supply outlets offer a selection of sunblock products fly masks and turnout sheets to protect horses against insects and excessive exposure to sunlight.
Horse owners should get veterinary advice if their horses develop serious reactions to sun exposure. Treatment may be needed to relieve pain and prevent infection. Especially in a horse that has never shown much sensitivity to sunlight a sudden or severe skin reaction may be a sign of liver disease or damage and early intervention by a veterinarian is critical in returning the horse to health.