[miss machine]

Can a horse really smell fear?

"There are two distinct olfactory systems, explains Diehl. The main olfactory system is involved with the conscious recognition of smells—"grandma's apple pie," says Diehl—and depends on the nose's ability to detect volatile, airborne molecules. When you smell coffee brewing, you're breathing in coffee molecules which bind to olfactory receptors in your nasal passages. Emotional states, including fear, are not typically regarded as capable of generating scent-laden molecules.

The second scent-detecting process is called the accessory olfactory system. Communication in this system begins in the vomeronasal organ, which is located above the soft palate of the mouth, on the floor of the nasal cavity. Highly specific smell molecules detected by this organ are transmitted to the accessory olfactory bulb where they are collected and processed. Nerves from both the accessory and the main olfactory bulbs project to the limbic system, the part of the brain that deals with emotional perception and response.

Instead of detecting airborne molecules, the accessory olfactory system is designed to "read" the messages of non-volatile pheromones, communicative chemicals emitted by all animals. Research suggests that pheromone molecules transmit information concerning territory, aggression, and most prominently, reproduction.

Diehl acknowledges that the accessory olfactory system's role in socially useful chemical communication could suggest that fear might be communicated by smell. The fact that smells are processed and interpreted in the limbic system would seem to offer another clue, as one of the limbic system's primary organs, the amygdala, is directly responsible for perceiving and responding to fear.

On the other hand, she says, it is widely acknowledged that pheromone communication via the accessory olfactory system is possible only within animals of the same species. This limitation makes it impossible for any animal to smell fear in members of different species.

Instead, Diehl suggests that an animal's sense of fear may depend more on behavioral clues than on olfactory signals. In horses, she notes, visual and auditory stimuli play a strong role in triggering behavioral responses.
If a frightened or nervous person approaches a horse, Diehl explains, the animal's ability to perceive this fear may help it avoid rough handling. A person who has never encountered a horse will hesitate if asked to grab its reins—"He'll reach up, then back away, then reach up again." The horse learns quickly that by making small movements away from that person, it can avoid being caught and mistreated. "Any horse can do this," she says. 'It's called operant conditioning.'"...

—Jillian Koopman

Nancy Diehl is an assistant professor of equine science at Penn State University. She can be reached at ndiehl@psu.edu.
Additional background information was provided by: Thomas Pritchard, Ph.D., associate professor of neural and behavioral sciences at Penn State University, tcp1@psu.edu; and Mimi Halpern, Ph.D., professor of anatomy and cell biology at Downstate Medical Center for The State University of New York, mimi.halpern@downstate.edu.


Copyright by The Pennsylvania State University

[MyBelgianAzzy]

Here's thw whole article. Research|Penn State: Can animals really smell fear?

On the other hand, I spoke to the gentleman who created Acclimate, and I have used both Acclimate and Vicks with great success.

[miss machine]

Whoops! Thanks for linking that.

Where you around other horses? Vicks/Acclimate could have interfered with smelling the other horse's fear. Also, having the safety net of altering what was smelled by the horse could have been comforting for you - therefore reducing your tendency to indicate nervousness through your behavior and your horse picking it up.

Just brainstorming here.

I've always worried that my pheromones could be smelled and my fear detected. Now that I have this information, I believe I can be more confident in masking my fear.

[cassidy]

i think when that is said can they smell fear i think it boils down to the fact that a horse has a sixth sence

[MyBelgianAzzy]

Yes, I was around other horses (shows, on a stud, etc) and the intention was to not let the horse smell other horses, which was the goal of Acclimate, the product mentioned in the article. It was never marketed to mask human fear.

Having read the study, I will agree horse's don't "smell fear", but I'm still certain they pick up on your body language both on the ground and on their backs. You can most definatley make your horse spooky by acting spooky, and calm them down by forcing yourself to relax.

[Dawn]

This is my theory on it and I have of course have no clue whether it's been studied or not.

It's not the 'smell' of fear. But rather the smells produced by fear.

Sweat. When you sweat, there are different types. You can sweat because you're hot, you're exerting yourself, or because you're nervous/fearful. If it gets to the point that we, as humans, can smell our's or other's sweat we can even tell a difference between the 3 types. Imagine with their more accute sense of smell that animals would be able to pick up on this not long after the sweating initialized. It is then a learned association that when the horse smellst his particular smell it will involve an encounter with a human that is scared/nervous which has the physical clues for the horse.

Because of this, using a high scent product can, at least temporarily, cover up the smell of 'fear'.

[miss machine]

Originally Posted by cassidy

i think when that is said can they smell fear i think it boils down to the fact that a horse has a sixth sence

But the article supports that horses can smell fear between their own species; they can't smell fear amongst other species.