From Trail Riding 101 My Horse University Online Course
Why Horses Spook
As a prey animal, horses by nature are very alert (vigilant). Nearly everyone has had the experience of being on a trail ride and having one person's horse spook, only to have all the other horses spook—even though the other horses don't even know what they're spooking at! Spooking is an irritating behavior, perhaps, but one that helped save horses lives in the wild. Understanding how a horse perceives its environment will help a rider know why a horse might spook. With this knowledge, the rider will be more equipped to anticipate when a horse will spook, as well as know how to handle the situation.
A horse uses their senses to make sense of a new environment.
Due to eye placement on the sides of their head, the horse has a large range of peripheral vision and is excellent at detecting movement. Peripheral vision is an excellent way to avoid predators that may attack suddenly by ambush. Their vision, though, is not as sharp as in humans. This is due, in part, to their small field of binocular vision. A horse will raise its head and neck to focus on an object in the distance, but will lower its head and neck to investigate an object that is close.
In horses, touch is a well-developed sense. This sensitivity helps them respond to subtle cues from us. The most sensitive areas on the horse are typically around the eyes, the ears and the nose. The flank area and legs are also sensitive. Horses are also sensitive to weight shifts while riding. The sense of touch "fatigues" easily, so pressure or touch used in training should be give-and-take and done in short sessions. Before riding on a rustic trail, horses should be desensitized to branches rubbing on their sides, under their barrel and around their legs and feet.
The sense of hearing in a horse is thought to be much keener than its sense of sight, but the eyes and ears are typically working together. While a horse's hearing is similar in range and tone to that of what humans can hear, their ability to rotate their ears 180 degrees allows them to point toward the sound and pick up more information. Even though the eyes and ears are usually working together, a horse does not necessarily need to see what is making the sound, and it may spook at a sound without actually seeing what is making it. They often learn to respond to extremely soft vocal cues, clucks, etc.
While relatively little is known about the sense of smell in the horse, its range of smell seems to fall between humans and dogs. Horses will use their sense of smell to identify other horses, humans and other animals. Horses may spook at very unfamiliar strong odors (like a pig smell).
Handling the Spooky Horse
Horses will instinctively respond to a new sight, sound, smell or unexpected touch by fleeing. We typically refer to this as the fight or flight response, understanding that horses are here today due to their ability to flee dangerous situations in the wild. When we put horses in an unknown environment with unknown events popping up (a backpacker turning the corner, a deer crossing a path) we should expect the inexperienced horse to spook. All good horsemen know that patience, consistency and appropriate use of the rider's aids are needed to build confidence in a horse. As a horse becomes more experienced and learns to trust the rider, a horse will develop its own sense of confidence and boldness in new situations. The following are some dos and don'ts for dealing with a spooky horse on the trail.
Do encourage your horse with confident aids using your hands, seat, legs and voice in unison to instill boldness in your horse.
Do acknowledge a horse's smallest effort to go towards a scary object by relieving some of the pressure from your aids or letting the horse stop and rest.
Do take your time to introduce a horse to a new situation - patience now will pay off the next time the horse is in a similar situation.
Do redirect your horse's energy by flexing their head and moving their shoulders towards and then away from an unfamiliar object. By taking control of the horse's movement, you can give them the confidence they need to get past the scary event.
Do ride with a more experienced horse that will lead the way for your less experienced mount.
Do start the inexperienced horse on short easy trails that are specific for equestrian use, then build up to more rustic and shared trails.
Do practice at home going through puddles, over logs, and accustom your horse to loud noises and your horse to branches.
Don't punish a horse for spooking - you will simply reinforce that there really is something to be scared about.
Don't try to comfort a horse for spooking with a lot of petting and soothing words - again you are just reinforcing the horse's initial assumption that this is a really scary situation.
Don't get off your horse unless you are in danger. You cannot lead a 1000 plus pound animal towards something if they really don't want to go.
Don't get in a habit of letting your horse stop at every unfamiliar object or new situation. Your ultimate goal should be to have your horse confidently handle unfamiliar situations without slowing down the ride.
Spook: When a horse reacts to an object, sound or smells by abruptly moving away from it.
Peripheral Vision: Vision outside of the center of the gaze and seen only with one eye at a time.
Binocular Vision: Vision out in front in which both eyes work together to make a single image. Binocular vision helps the brain determine relative sizes and distances of viewed objects.
Desensitize: Familiarize a horse to an event by involving all of the horse's senses and repeating the event until the horse no longer reacts adversely to the event. An example would be rubbing a blanket on the horse's back until the horse stands still and does not react to the blanket.
Riding with steady aids will instill confidence in your mount.