My horse was pulled for lameness at the completion of one of
his 50s due to scratches that developed during the ride. This ride was muddy in
spots, but it wasn’t rainy, so once he got the muck on him, it stayed for
awhile. After that, I now usually use a generic diaper rash ointment on him and
he hasn’t gotten them again. This year, it was raining at the ride
he’d gotten them on, soaking rain, and I didn’t use the ointment,
but he didn’t get the scratches. Probably whatever causes them for him
washed off.