Horse senses

Sight

Horses have keen sensory perception developed from their evolution.
The horse has one of the largest eyes of any modern animal.
It has a special light intensifying device that reflects light back onto the retina, making vision in poor light very good. In the wild, they are active at dawn and dusk.
The eye structure allows it to see the slightest movement so will panic easily by something on the periphery of its vision.
Having a binocular vision in front of 60-70° means the horse needs to move the head to see where it is going. It can only focus fully for a short distance ahead - about 2m.
This is a problem in jumping - it focuses then must remember and trust its memory of the object.
Horses have a wide monocular (panoramic) view of the horizon and can see about 340-360° around it.
As the eyes are on the sides of its head, the horse does not normally see objects in depth. It sees them as we do with one eye closed. It sees them with less detail than humans but is more sensitive to movement.
Eyes are perfectly placed for cropping pasture, which it does for half its life!
The horse’s visual area is more towards the ground than the sky.
The horse can raise its head quickly and focus on objects at various distances away from it.
Colour vision is still debated. Some work shows the horse can see colour starting from yellow, green, blue, and red in that order.
A hose needs time to adjust vision between light and dark. Remember this when loading.
The horse has a blind spot behind its head which increases when the head is lifted. So it is important to allow the horse to move its head to see objects in its way.
Horses are generally reluctant to enter dark enclosures but quieten down when in there and feel safe looking out into the light. Horses are often blindfolded to quieten them.
Don’t look a strange horse in the eye. It’s a threatening pose.
A horse will go in the direction it is looking so point it correctly.

Hearing

Horses have a broader range of hearing than humans and can hear up to 25,000 cps.
They have an acute hearing in the high and low frequencies.
Humans noticed their early response the earthquake vibrations.
Horses have 16 muscles that control the ears which can swivel 180 degrees.
When ears are laid fully back this cuts their hearing severely.
Horses are alert at all times except in deep sleep which it does in very short spells.

Smell

The smell is well developed in the horse. Wild horses are difficult to stalk except upwind.
Horses meet nose to nose and smell each other.
Horses are sensitive to smells in their environment - dung, dirty troughs, musty feed, bad water, and certain plants.
The smell is very important in feed selection.
The horse has a vomeronasal organ (VNO) and the flehmen response is very obvious in stallions sniffing mares in heat.

Taste

Horses are attracted by sweetness and sugar, molasses, watermelon rind, peaches, and beer are relished.
They (especially foals) reject salty, sour, and bitter tastes at about the same level of acceptance as humans.

Touch

Touch is one of the most acutely developed senses in the horse.
They can sense a fly landing on any part of their body through their coat to flick it off.
Horses are “inter-pressure”. They respond to pressure so when you move into the horse you will get a reverse response.
Horses respond to touch all over the body but especially around the head.
Ears and eyes are especially sensitive areas. They don’t like their ears pulled.
The upper lip and muzzle are very sensitive to tactile stimulus and are equivalent to our fingers.
The whiskers that grow from the muzzle and around the eyes are like an insect’s antennae. They are especially useful in low light conditions when the horse is nosing around. You should not cut them off!
Touch plays a major role in their social life.
Riders use touch to signal intentions to the horse.
Horses use muscles in their skin to disturb flies.
Horses push and barge each other in physical contact to communicate.
When leading a horse - be positive.
Horses have a “point of balance” behind their shoulders and in centre of heads like cattle.

Memory

Horses have a very good long-term memory.
This is useful for an animal that grazes over a large territory.
It can be seen when a horse will remember a place where it got a fright and will continually shy at that place.
But it can be variable and reinforcement in training is important.
A horse will learn nothing when under stress - as the survival urge will blank out memory.