A friend of mine had a horse with photosensitivity and literally in a couple days time his legs swelled up and the sking started sloughing off. It was bad. She had to keep in indoors as much as possible during sunlight hours and keep sunscreen on his white parts. I think they now make a few sun protective clothing items for horses as well, but never heard how well they work. My friends case was pretty extreme, I sure hope your horse is less sensitive. Good luck and sorry I wasn't much more help, I just know that's what she had to do.
keep him off pasture for sure until you get rid of most of the clover. clover dies out usually when it gets really hot so it should be calming down now. do you have a drylot to put him on?? I would also only turn him out at night until hes all healed up
We had a mare this happened to last year. We had to give her massive doses of steroids and keep her out of the direct sun. As soon as we did that she healed right up, but we had to make sure she was always in the shade.
There is a spray called Pasture Pro at Tractor Supply...you spray on clover and it kills it within a day or so....we spray it every summer...does a great job. I too knew someone who had that happen with their big horse...was awful.
I had a half dozen of my white-faced horses develop photosensitivity from a buckwheat weed in their hay. The entire skin around their eyes and mouths -- wherever they had exposed white skin on their faces blistered, skin split, weeped and sloughed off. I wanted to cry everytime I looked at them. THey looked like they had been in a barn fire. One mare, a tovero mare with lots of white and pink eyelids, was really badly affected with a temperature and elevated liver enzymes. Treatment consisted of no sun exposure, obviously, zinc oxide in any areas where the ointment might get drippy in the heat and run into their eyes, Silvadene cream (just like they use on human burn patients) for the other areas along with hydrocortisone. The horses were so sore, they would barely let me touch them to medicate the areas. It was just awful. I should have taken photos for reference, but couldn't bear to as they were in so much pain -- seemed like I was exploiting them
. Anyway, it took several weeks to completely heal and I still frequently put zinc oxide on the tovero mare and double dilute mare's faces because the new skin they grew is very sensitive. The good news is, as bad as the burns and skin sloughing were, there are no permanent scars. Thank goodness for small favors!
Good luck with your horses and getting rid of that clover.
All legumes, clovers included, are easily controlled with 2-4-D, which will not kill grasses. 2-4-D is a widely used herbicide that you should be able to get at any garden center. Spray during the heat of a sunny day for best results. There is a 'no graze' period after using this product, so check the label carefully.
A non-chemical control is strong vinegar (the pickling kind, not the 'white' vinegar). Also apply in hot sun. This will fry the grass as well, so is best for spot spraying.
When clover spreads in a pasture, it's often a sign of a nitrogen deficiency (legumes are great nitrogen fixers). Likewise, when grass starts to crowd out the clover, there is sufficient nitrogen to sustain the grass and it will replace the clover.