Horses’ Sense of Smell, Taste, and Touch

Horses have strange smelling behaviours, pickiness about feed, and an extraordinary sensitivity to touch. In this post, we dive into horses’ senses of smell, taste, and touch.

Sense of Smell

Horses’ sense of smell is about 50 times better than humans’, although not as powerful as dogs’. Their noses can distinguish the scent of predators, other horses, medications hidden in their feed, and even possibly human emotions, like fear and happiness.

Horses have anywhere from 25 million to 100 million olfactory receptors, which help detect scents. The human nose contains 5 to 6 million receptors, while dogs and rats have about 300 million.

Horses’ large, flexible nostrils suck air into their large nasal cavity. Inside the cavity, turbinate bones distribute inhaled air, and tiny hairs slow it down to trap it in mucus. Horses can identify a scent’s direction because each nostril’s receptors connect to separate parts of their brain.

Like several other animals, including cats and pandas, horses have an organ known as the vomeronasal organ (VNO) at their nasal cavity’s base. In horses, this organ’s most significant role is detecting other horses’ pheromones - chemical substances that affect animal behaviour. More specifically, stallions will use the VNO to determine whether a mare is in heat.

To direct odours to their VNO, horses use the Flehmen response, lifting their head up high, peeling back their lips, wrinkling their nose, and temporarily stopping breathing. Horses sometimes also use the Flehmen response for strong, unfamiliar smells like perfume and gasoline.

Horses often sniff each other’s nostrils when they first meet. Mares fix their newborn foal’s scent into their brain while grooming it. However, horses can also form negative associations with certain smells.

Sense of Taste

Horses’ taste buds are located mainly on the roof of their mouth and the back section of their tongue. They have approximately 25,000 taste buds, compared to between 8000 and 10,000 for humans.

Horses can distinguish between different flavours, like sweet, salty, sour, and bitter. They tend to prefer sweet and salty foods, perhaps because sweet foods fill them up, while salty ones replenish their salt levels. Sour or bitter foods, however, risk being poisonous.
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If there’s plenty of grass or hay available, horses will eat the foods with the most appealing taste and texture, although they tend to avoid toxic plants. Left to their own devices, horses will not necessarily choose the most nutritious option and may consume more food than is necessary to meet their needs. 

Horses tend to prefer young, tender plants to mature, tough ones. They may refuse food or water with an unusual taste or smell. However, they’re less choosy when hungry. 

Sense of Touch

Horses’ sense of touch is highly sensitive, especially around their nose, lips, and ears. They can feel a fly landing on their back and the rider’s slightest shift of weight in the saddle. A particular horse’s level of sensitivity depends on factors including its age and the thickness of its skin.

Horses use their coarse whiskers - found around their muzzle and eyes - to gather information about their environment. They’ll paw the ground then touch it with their muzzle to check its safety, firmness, and depth.

Those who ride and work with horses should use a light touch on the reins and ensure that tack fits correctly. Know that horses prefer being rubbed and stroked - in non-sensitive areas - to being patted or tickled.

Do you have a favourite fact about horses’ sense of smell, taste, or touch? Let us know in the comments!