Photosensitivity in horses

What is photosensitivity and what causes it.

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Photosensitivity is where the skin of horses becomes red, inflamed, peels and can become very sore and infected.

That normally happens in hotter weather when the sun is strong, this is like severe sunburn but it’s not just from exposure to the sun.

Exposure to the sun is an issue generally with horse with non-pigmented skin (white or pink) generally around the muzzle, face mainly eyes, and lower legs. These are often the areas that are most frequently affected.

Some horses with pink skin or white patches are never affected above mild sunburn and slight reddening, but others get severe reactions that can turn into photodermatitis, very severe reaction to UV light exposure (sunlight)

There are two reasons why a horse mainly suffers from photosensitivity over sunburn.

Primary and secondary photosensitivity.

Primary photosensitivity happens when the horse’s skin is exposed to sprays that are oil based, like pig oil, coat shines and other cosmetic grooming products; some creams can also cause an oily residue that attracts the sun also some Antibiotics, steroid creams or tablets or sedatives can cause problems, but your vet will normally warn you if you are required to keep your horse out of the sun.

Some common plants and weeds that when being eaten or grazed over can contribute to photosensitivity like buttercup, clover, St Johns Wart, Hogweed are very common weeds that cause photosensitivity when in paddocks.

Secondary photosensitivity is usually from a under lying liver issue, where the body builds up toxins in the body, this is hard to work out as it displays the same as Primary Photosensitivity. This can also be caused by grazing toxic plants.

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What photosensitivity looks like?

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Photosensitivity can present in a few ways the most common:

• Uncomfortable, twitching in Direct sunlight

• Rubbing or itching the skin

• Red or pink skin

• Blistering or peeling skin (like sun burn)

• Swelling

• Heat

• Scabs

More extreme or left untreated symptoms:

• Fluid filled lumps

• Open wounds

• Infection

• Dead skin and tissue

Each horse is affected differently in severity

How to treat:

• Soothing creams

• Turnout at night

• Covering with UV resistant sheets and masks

• Vet prescribed creams

• Sometimes injections will be administered by vets.

How to prevent:

• UV resistant/blocking cream

• Thick strong sun creams (but need to be applied often)

• Keeping out of the sun, stable during the day and out at night

• Keep fly masks and rugs with 80% or more UV block

• Keep paddocks weed free

• Keep white & clipped areas covered during day light hours

Avoid using oil-based products during the day

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Note:

I would like to advise taking great care when using creams, as horses become sore and irritated, they may not want you playing around with creams and lotions while sore, masks and rugs can help reduce the UV exposure and let the skin start calming.

Get help if you need to.

If an infection develops call your vet and get their assistance on getting on top of the problem.

Keep masks clean and well-fitting make sure there not rubbing.

Every horse is different so remember one thing does not work for all.