Horses blink less when stressed

The way a horse’s eyes blink and twitch can reveal their stress levels, according to new research from Canadian scientists.

The study, which was published in Animals, found that horses blink less and twitch their eyelids more when under mild stress.  

As part of the research, 33 horses of different breeds were exposed to three different stressful situations.

In the first situation, a ball was thrown in the direction of the horse to startle it.

In the second, the horse was visually separated from the rest of its herd for a few minutes.

In the final scenario, the horse’s food was withheld for three minutes at feeding time while other members of the herd were allowed to start eating.

Scientists filmed the horses watching for changes in eye and ear movement, head tilt and general restlessness.

The film revealed that blink rate reduced among the horses when exposed to a stressful situation, while the horses twitched their upper eyelids more.

The full blink rate of horses decreased from eight to nine times per minute when relaxed, to five times per minute when stressed.

Image credit: Pixabay/manfredrichter