Ah, the equine connection to ketamine! Yes, indeed, ketamine was initially developed as a veterinary anesthetic and used primarily in animals like horses. Its unique properties as a dissociative anesthetic made it useful for sedating large animals while preserving their respiratory function—a handy tool for veterinarians performing procedures on our four-legged friends.

However, ketamine's versatile effects soon caught the eye of researchers and clinicians in human medicine. Its ability to induce anesthesia quickly with minimal impact on breathing function made it valuable for use in emergency rooms, especially in situations where rapid sedation or anesthesia was required.

So, thanks to its successful stint as a horse tranquilizer (though let's not mention that at parties), ketamine found its way into human medicine and eventually into recreational settings where its dissociative effects became sought after by those looking to explore altered states of consciousness. Who knew that something originally meant for horses would become such a party hit?