Last year one of my clients had a mare who was suffering severely from sunburn on her nose. She`s a piebald mare so has a fair bit of pink skin and white hair, but it was strange how badly affected her nose was considering that suncream had been applied daily and she wore a fly mask with a nose net to protect her.
I had seen this sort of angry, red sores before on a liver chestnut with a white stripe, and that was treated by the vet with flammazine cream and the mare was diagnosed as having photosensitivity issues. I think the blood test results showed abnormal functioning of the liver.
So I told this client about this other horse and left her to read up about it.
The liver removes toxins from the body before they can damage other organs and systems in the body. Disease and heavy drug use (for example, horses on a low-level dosage of bute for long-term) can affect the functioning and efficiency of the liver.
Horses detox their body via the digestive system, kidneys and urinary system, liver, lymphatic system, respiratory system and through the skin. Herbal remedies can be used to aid detoxication, but should be a low strength so that the horses delicate digestive system. The most common herbal supplement for liver support is Milk Thistle.
Milk thistle contains Silibinin which protects the liver by preventing certain toxins from entering the liver cells and stimulates regeneration of damaged cells. It also boosts antioxidant activity as well as increasing the oxygenating function of red blood cells.
If your horse was on long-term courses of drugs then your vet might recommend feeding a milk thistle supplement to support the liver. Research has shown that horses being treated for Lyme disease, EPM, or other chronic diseases have benefited from a milk thistle detox a couple of times a year.
This year, the coloured mare has been fed milk thistle seed, in the powdered form which is supposed to be the most digestible. She has definitely benefitted from it as her nose doesn`t have the crusty sores that she did last year. Her nose is covered in sun cream every day, and she definitely still needs it as on sunny days it still looks a bit pink, but it is a normal reaction to UV rays. I guess you could check that her fly mask and nose net are UV proof as that would provide her with more protection, and potentially when riding out on hot days a UV nose net could be attached to her noseband for added protection. In more severe cases (possibly a horse with more white throughout their body) they could end up with the scabs on other areas of their body, especially where the coat is thinner and the skin more sensitive, so would benefit from a UV rug.
If your horse tends to get sun burn similar to the above photo, it would be worth speaking to your vet and considering feeding a supplement that supports and promotes liver function as well as superficially protecting them from the sun with masks and cream.