I used to use either Bachs Remedy, or Chill by Omega Alpha.
Bachs Remedy I could also use on myself, cause I would sometimes find myself just a bundle of nerves. It takes that edge off, still keeps you alert and focused, and it did the same for my horse. Tastes like tequila though.. no there is no actual alcohol in it
I bought it from G&E Pharmacies in Edmonton.
Chill I would syringe bout a half hour before a run, and it had a similar effect to the bachs remedy. Kept the edge off, yet he was still able to focus, and still had lots of gas to burn. You can get this at most feed and tack stores.
You could probably also google Tracy Sharpe, or Shauna Cole and have them make you something more tailored to your horses exact needs, that would help calm your horse!
You get what you expect out of yourself, so always expect the BEST! - Lee Ann Rust