I disagree about Ace not making horses go nuttier. All drugs have to potential to have adverse reations with some animals. One can never predict every horses or animals reaction to any drug if it has never had it before.

We once sedated a colt at university for a small procedure. It went absolutely crazy. It got it's front feet over the front of the 6 foot high crush. We thought it was going to kill itself and everyone trying to help it. Not one on the other 20 we did that day, had an adverse reaction, but it can happen.