Christopher Pike and Tango, a horse
- "Spock!"
- "Yes, captain!"
- "Be one with the horse!"
- - Kirk and Spock
The horse (Equus caballus) was a mammalian hoofed quadruped native to Earth. For centuries, these animals were used for transportation by Humans, though horseback riding became primarily a recreational activity.
Horses were used by the soldiers on Earth in cavalry raids. (DS9: "Once More Unto the Breach")
In the mid-19th century, a number of horses were taken from Earth along with several thousand Humans by the Skagarans and resettled on a planet in the Delphic Expanse. After the overthrow of the Skagarans, horses were still used as transportation by Humans until at least the mid-22nd century. Enterprise NX-01 crewmembers Charles Tucker and T'Pol acquired horses for riding while secretly investigating the planet, though T'Pol had some difficulty with her horse. (ENT: "North Star")
Horses were used to carry buggys in the 19th century on Earth. Data saw some horses when he was accidentally brought into San Francisco of 1893. (TNG: "Time's Arrow", "Time's Arrow, Part II")
Christopher Pike once owned two horses, one named Tango, prior to his service aboard the USS Enterprise. (TOS: "The Cage")
In the alternate reality created by Nero's temporal incursion, Montgomery Scott described the notion of transwarp beaming as being like "trying to hit a bullet with a smaller bullet, whilst wearing a blindfold, riding a horse." (Star Trek)
In noting Scotty's timing with repairing the Enterprise just as they reached Spacedock, following her battle with the USS Reliant, Captain Kirk remarked that he "fixed the barn door after the horse has come home." (Star Trek III: The Search for Spock)
James Kirk's uncle owned a farm in Idaho which contained horses. Kirk often rode his uncle's horses through the countryside and would often jump over a large chasm, an act which "scared the hell" out of him each time. It was during one of these horseback rides that Kirk met Antonia in 2282. Kirk revisited the farm while trapped within the Nexus and, along with Captain Jean-Luc Picard, rode a horse out to meet Antonia in an attempt to "do things right from day one." It was only after having no fear when jumping over the familiar chasm that Kirk realized what he was experiencing was not real, and opted to leave the Nexus with Picard. (Star Trek Generations)
A type of alien horse was seen on the planet Nimbus III in the 2280s. The army of Sybok used horses to attack Paradise City, as did a Starfleet raiding shortly thereafter. The horses on Nimbus III could be subdued by a Vulcan nerve pinch. (Star Trek V: The Final Frontier).
Captain Picard gave a statue of a horse created in the Chinese Sung dynasty as a gift to the Ligonian ruler Lutan in early 2364. (TNG: "Code of Honor")
Picard and Troi with a horse.
Programs featuring riding horses were stored on the holodeck on the USS Enterprise-D including Equestrian Adventure. Captain Picard himself was fond of horseback riding and actually had a saddle aboard the Enterprise. (TNG: "Suddenly Human", "Pen Pals", "Starship Mine", Star Trek: First Contact)
When in 2369 the imaginations of the Deep Space 9 residents became reality, Julian Bashir created an illusory Jadzia Dax who told the real Jadzia Dax that she should get off of her high horse and appreciate Bashir. (DS9: "If Wishes Were Horses")