Overview
- Horses smelling fear-related human odors showed reduced willingness to approach or touch a person compared with joy and control scents.
- Fear odor exposure produced stronger startle reactions to sudden events and more sustained staring at a novel object.
- Maximum heart rate increased under fear odor conditions, with physiology tracked alongside behavioral measures and saliva cortisol sampling.
- Odor samples were collected on cotton pads from volunteers watching fear- or joy-eliciting clips and then placed at horses’ nostrils using a custom muzzle.
- The authors underscore welfare and safety implications for handlers and plan studies to identify the chemical compounds and assess other emotions, including whether humans detect horses’ emotional odors.