Ulcerguard ie omeprazole works in no way as a depressant on the central nervous system. It is not a calming agent. It blocks the secretion of acid from parietal cells and has zero to do with the cns. This action decreases the risk a stressed horse will develop ulcers. It does not calm horses. Perfect Prep and other products are marketed as calming agents because they depress the horse’s CNS. This is specifically prohibited.
ETA as someone who deals in all manner of sedatives tranquilizers and CNS depressants professionally I can attest there is nothing in Ulcerguard that acts as a calming agent. And calming pastes have ingredients that do act as CNS depressants. Maintaining a horses demeanor because they are not in pain due to ulcers due to an acid blocker is a vast difference than administering a CNS depressant to overcome nervousness, pain, tension or excitement due to a novel environment. Two completely different mechanisms of action, one which is prohibited. Ulcerguard does nothing to dull a horse’s senses or reflexes.