My horse's lessee called me a little bit ago to let me know that Sam came in from the pasture today with his eye a little swollen/runny/itchy. I remember last year right around this time, the same thing happened, same eye (a little runniness in the right eye, but mostly all left eye), and a couple other horses at the same time all had the same symptoms. Same thing has happened a couple times with my horse, and looking back, I think it's always been in the fall. Usually I just wipe it down, cool compress, maybe a rinse of Clear Eyes, and it's much improved the next day, and then he'll have a little bit of tears for another day or two and then it's gone entirely.
Is there something that tends to crop up in the pasture at this time of the year that he's likely allergic to? Anyone else had this happen?