A very sad story, but an important warning. Please fence off your Oak trees at this time of year 
We have LOTS of acorns this year, and because of the early autumn windy weather we are experiencing they seem to be dropping much earlier too. We know some of our horses have a taste for acorns, but we always fence off a wide area around the trees regardless. Clearing them up just doesn’t work, it’s impossible to know what your horse has eaten in between.
Article: Owner’s warning after two horses die from acorn poisoning