That could a pic of my Arab's face you posted
I had everyone shut out of one of the pastures for a couple weeks because my 21+ horse, that is metabolic, injured a tendon in the pasture. It is on a really steep hill and the turn at the bottom, coming back into the main pasture, can get slippery.
Anyway, I opened that back up and, just as I suspected, the Arab and the metabolic horses' faces have been "poisoned" by something up on that ridge.
I know we have a variety of pig weed, a variety of nettle, poisons ivy, oak & sumac, and who knows what else up there.
I wouldn't even know where to begin fencing because the "stuff" could essentially be traveling so far down the hill that I wouldn't get it all anyway.
We put D-2-4 on it in spring, 2007 and that didn't help, so that tells me that I would have to put an all-kill down (and most likely still not get it all). In turn, that would mean keeping the horses out of there for "months" as far as I'm concerned. I know the beef owners put their cows back on sooner than that, but I would fret too much over the horses.
The skin issues only last from about now until mid-September where I live. Hopefully the Vitamin E I have them on will help the healing process from the sores. If skin allergies get too far out of control, I will put them on Tri-Hist for awhile
Life sure has changed - I was raised on dairy farm, my grandpap had beefers and Welsh/Morgans. We never had issues like this. Back in those days we fed our own corn, oats & hay and the seed used to grow those things was not "hybrid" seed, and the fertilizer was probably of more pure quality.
No skin allergies, the only ticks we saw were on the dogs, coggins didn't exist, no one got shots except the farm dog for rabies.
Our worst worry was picking up a bale of hay with a "live" swamp rattler in it. Yes life really was simpler and I miss it - lol lol lol lol