From: Lorelei
Dear Jessica,
I got to thinking the other day about people and skin cancer from UV rays, my second thought was, "If people get skin cancer from the sun how come I never hear of horses dying from cancer caused by the sun?" Are horses just "used to' the sun? Or can horses get skin cancer from the sun? I know horses with white coats and pink skin can get sun burnt quite easily. And what about the horses with dark skin? Are they susceptible to getting burn
Lorelei
Hi Lorelei! What a very interesting question that is -- I can't give you a definitive answer, but I can tell you what I know about the subject. ;-) For better and more up-to-date information, ask your vet what's new in that area of research!
Horses may very well get skin cancer from the sun, but I would guess that we might not hear about it because most horses don't live long enough to die from it. It makes sense that repeated sunburns could lead to skin cancer in horses, just as they tend to do in humans, but there probably aren't a huge number of cases in which such cancers develop and are diagnosed as such.
After all, if humans get badly sunburned as children and as adolescents, they may very well, in their forties or fifties or later, find that they have skin cancers -- IF they have themselves inspected by good dermatologists. (Some don't, and find out too late that the skin cancer has spread.) But in horses, a condition that could become fatal thirty years later is likely to be ignored even if it is diagnosed, because it won't be a problem -- the horse will almost certainly die of some other cause long before the skin cancer could become fatal.
Horses do have an advantage over humans in that they have a lovely hair coat that protects them from the elements, including the sun. You're quite right about sunburn! Dark skin and hair are more protective in horses, just as they are in humans. Just as some human types, especially the very pale, light-eyed Caucasians, are more susceptible to sunburn, skin cancer, and premature ageing of the skin, grey horses (ones with pink, rather than black, skin) can be prone to tumours, and horses with pink skin and white hair around the eyes are more susceptible to sun damage. In the summer, it's not uncommon to see horses with peeling noses. Sunscreen can help a little, but many horses will lick or rub it off their muzzles, and it has to be reapplied often.
Some bald-faced horses spend their summers in fly masks that cut the ultraviolet rays as well as blocking the flies. Some horse-owners routinely use sunscreen around their horses' eyes, and some have gone so far as to have the skin around their horses' eyes tattooed with dark pigment. I've only seen this twice, but it appeared to be quite effective. The cost is probably high, though, just as it is for humans who choose to have eyeliner or eyebrows tattooed in place. ;-)
Jessica
Jessica Jahiel's HORSE-SENSE is a free, subscriber-supported electronic Q&A email newsletter which deals with all aspects of horses, their management, riding, and training. For more information, please visit www.horse-sense.org
Please visit Jessica Jahiel: Holistic Horsemanship® [www.jessicajahiel.com] for more information on Jessica Jahiel's clinics, video lessons, phone consultations, books, articles, columns, and expert witness and litigation consultant services.