Saw this post has been idle a while.
Over the summer, one of my barrel horses became a big handful when it was time to run. Thought maybe it was arena sour, tried new pad, less grain, etc. Never saw any sign of bleeding. Then about a month ago, it was mentioned that he might be bleeding. It was not until then that it dawned on me that after a run, he would sneeze 4 or 5 time and rarely cough.
After talking with the vet, we decided to try a dose of Lasix at the next barrel race since it would not be possible for her to be there to scope. He did not sneeze or cough.
I have done a lot of google searches on EIPH supplements and found MANY opinions. Like feed and other supplements, everyone has their opinions and some might work for one horse but not the next.