Recent research in Colorado suggests tattoing can reduce soreness around the eyes.
Horses with white patches around the eyes risk diseases such as solar blepharitis (inflammation of the eyelids) and squamous cell carcinoma as a result of the effect of ultra violet light on the skin.
An obvious step to try to prevent these problems would be to introduce pigment to the non-pigmented skin. That's exactly what Dr Glenn Severin has been doing for 40 years at Colorado State University, reports Equine Science Update.
He started tattooing horses' eyelids in the 1960s. He hoped that doing so would prevent blepharitis and possibly also squamous cell carcinoma, the most common tumour found around the eye of horses.
Now a recent study has looked back at some of the results. Dr Julie Gionfriddo and colleagues in the Department of Clinical Sciences at Colorado State University reviewed the records of 26 horses tattooed between 1980 and 2007.
Horses were chosen for treatment because they had no pigment around their eyes. They were anaesthetised for the procedure. Black tattoo paste was applied to the white skin of the eyelids. Then electrically powered tattooing machines were used to work the paste into the skin, taking the tattoo paste with them. The procedure was repeated until the desired effect was achieved.
Mild swelling occurred, which resolved after 7-10 days.
No harmful effects were reported, and most owners were satisfied with the cosmetic result. In two cases, the owners thought the tattoo faded too much. One owner reported that the horse became head shy after having the procedure done.
Tattooing may well have protected the skin from ultra violet light. Most horses had suffered from sore eyes (sunlight related-blepharitis) before being tattooed. None had a recurrence after treatment.
So, the technique seems to be safe. It also appears to be helpful in reducing soreness around the eyes caused by exposure to ultraviolet light. Further work needs to be done to see if tattooing actually helps reduce the risk of tumours.