Horse sense useful

By Marty Metzger
North Forty News

Equines are prey animals, so their survival is determined by reaction to the world around them. Incoming data is discerned by and sorted in the brain via the same five senses that humans have: sight, hearing, smell, taste and touch.

Sight

The size and position of horses' eyes give them an almost 360 degree field of vision. Two blind spots, however, hinder an otherwise perfect outlook on life. These areas are directly in front of the nose and up to a few feet behind the rear. One of the first safety lessons novice horsemen learn is to never walk up behind a horse, especially quietly.

Depth perception and color are subjects of ongoing research and debate. Recent studies debunk the once commonly held notion that equines are totally color blind. According to Fort Collins veterinarian Dr. Richard Wheeler of Poudre River Veterinary Clinic, rods and cones in the retina detect color. Horses do have these, just fewer than do humans, so nuances of shades are less intense. For example, your horse might see that your shirt is red but be unable to distinguish its tone from your lighter red hair. Wheeler, a board-certified reproduction specialist, has observed that some stallions prefer mares of a certain color. Dr. Andrew Dean of LaPorte Animal Clinic said that horses are more able to perceive color than are dogs.

Hearing

The ears are like big, conical antennae on a horse's roof. Each can work independently of the other. One ear might flick forward at the sound of a human rattling the grain bucket while the other cocks back toward a nickering herd mate. This double-minded reaction can frustrate the human when the horse chooses the herd.

Smell

This is a highly developed equine sense. Foals and their dams recognize one another partially by scent, and each herd is thought to have a unique, corporate smell. When greeting, equines often blow into each others' nostrils. Home is identified by scent. Horses can smell specific human odors, thereby detecting fear, anger or nervousness in handlers. A reaction called Flehmen (curling back of the upper lip, thereby exposing a scent gland) occurs when a stallion inspects a mare in heat. Pheromones are thus directed through the vomeronasal organ. Peculiar or strong smells/tastes also trigger this response.

Horses sometimes sniff dung to identify herd interlopers, such as a rival stallion or newly introduced individual in their enclosure. The scent of water has been touted to draw thirsty horses from as far as two miles.

Dean believes horses recognize the scent of a veterinarian and his or her truck. This usually elicits a negative response. He believes unpleasant experiences, like getting shots, set up a negative memory tied to the scent.

Troublesome to horse lovers is the species' strong sensitivity to the smell of blood. In the wild, this perception produces a life-saving flight from peril response. Equines at slaughterhouses display profound terror as they are prodded down the line.

Taste

Wheeler said that horses can differentiate four distinct tastes: sweet, sour, bitter and salty. In his opinion, they have an incredible sweet tooth. Some sources contend that horses are also partial to chicory and other bitter herbs.

Kelcey Swyers, an animal nutritionist at Ranch-Way Feeds in Fort Collins, said that texture and size influence feed choices. Leaves are preferable to stems. Grazing animals eat young, short grasses before eating long, stemmy ones. Swyers also named apple, wintergreen, banana bread and molasses as highly palatable to horses.

Dean added anise and fenugreek to that list.

Touch

This sense is vital in equine/human interaction. Although the horse is always alert for predators or other dangers, and is fearful of entrapment, the sense of touch is important in social interaction.

When greeting, horses nuzzle. They combine sight, smell and touch to identify friends or strangers. Mutual chewing on each other's withers to scratch itches strengthens bonds. Whiskers on muzzles evaluate hard-to-see objects (remember the blind spot at the end of nose).

Swyers said that the upper lip functions like an opposable thumb and can sort oats from corn, minerals from a grain mix.

Wheeler considers the muzzle the greatest sensory organ for equine touch. The whiskers are critical to this intense sensitivity.

A horse is capable of sensing even the slightest of touches. An animal able to withstand hundreds of pounds of rider on its back can detect the legs of a tiny fly.

Feet are very sensitive, as well. One manner in which a horse tries to identify objects on the ground, like a hat, is pawing at it with a hoof.

The five senses work in unison to send survival and social information to the brain. It in turn forwards stimuli to organs and limbs that react appropriately to each particular situation. A horse sensing potential danger might flatten back ears or flick them back and forth while loudly blowing or snorting. Its head is alert, eyes focused. If the threat persists, heart pumps faster and a speedy getaway follows. In a social setting, two horses meet up in a field, ears flick, scents are checked out and, if an amiable result ensues, heads drop to contentedly graze.

Equines in a group read one another's body language. Lip licking, for example, can be a sign of submission.

Trainers and handlers are well-advised to "read" their horses. A stallion in the wild would stampede behind or nip at the slowest individuals in his herd to move them away from danger. Drovers know to yell or crack whips from behind to propel horses forward or turn them. So, the worst thing a rider on a bolting mount can do is to scream; it confirms fear to the horse, which then flees.

A sixth sense of heightened perception is sometimes displayed by horses, rarely in humans. Wheeler said this might account for horses' uncanny ability to detect certain ailments.

One Saddlebred gelding never failed to anticipate its young owner's grand mal seizures well before she did. When she rode, and he sensed one, he'd stop and refuse to move. Every time, and within moments, a seizure followed. Had they been cantering, she'd have suffered certain injury when she fell off. Also well-documented is horses' reluctance to pass reputedly haunted places.

Each horse has a distinct personality, influenced by senses and experiences. Apathy or ignorance of the senses by people can ruin an animal or jeopardize human safety. Knowledge and observation of them can make interaction with equine friends mutually gratifying.