Horses Reveal Hidden Stress as Wolves Appear on Silent Video

Ohio State researchers found horses instantly recognize predators like wolves on a silent video, triggering rapid heart-rate increases even as they appear calm and unmoved. The stress is greater in males and dominant horses, suggesting internal agitation may accompany outward composure. Eye movement data imply quick cognitive assessment within 20 seconds, challenging the idea that prey animals only panic and run. Findings have welfare and rider-safety implications, especially around canines.