Your horse’s face reveals pain

5. September, 2023

Your horse’s face reveals pain

Did you know that Danish research shows that your horse’s face reveals whether it is in pain?

That knowledge supplements already existing knowledge about how you assess whether your horse is in pain.
The Danish research team Karina Gleerup, Björn Forkman, Casper Lindegaard and Pia H Andersen are behind the discovery. They studied six horses that showed very specific changes in their facial expressions when exposed to pain. The pain to which the horses were subjected was the same method used in human pain research. Simply put, it’s a cuff, as you know it from blood pressure measurements, with chili paste underneath.

Pain is perceived differently

To, one of the researchers behind the experiment, Karina Gleerup, said that as a veterinarian and horse lover it was a big challenge to expose horses to pain, and that it therefore took place with many reservations:

“- I first tested the sources of pain – which are frequently used in pain research on humans – on myself. Two types of pain were needed to see if the pain signs were the same. In addition, I had trained the horses a lot beforehand, so they were completely comfortable with the situation. Then I was also sure that it was pain and not, for example, stress, that I could read in their faces, she says.

The experience of pain is very individual. What hurts you a lot hurts me less. Or the other way around. What hurts a lot today hurts less tomorrow. It is the same with horses.

The experiment also showed that there was a difference in how clearly the horses’ faces revealed their pain. There was both a difference from one horse to another, and between the same horse from trial to trial.

How to look at your horse’s face to see if he is in pain

The ears:

If your horse is in pain, it has a greater distance between the ears, and they get an outward rotation – i.e. out to the sides. It may also be that the ears are asymmetrically positioned. If the horse puts its ears back, it can also be a sign that the horse is in pain.

Forehead and eyes:

A “frown forehead” or “worried expression” in people is often interpreted as a sign that everything is not quite as it should be. The same applies to horses.

We see it as a worried expression on the horse’s face, but it is probably in reality a tension in the horse’s eyes, so that they get a slightly triangular appearance. At the same time, the gaze is not present but more inward.

The nostrils:

When a horse is in pain, its nostrils may become dilated and tense. When the horse breathes in, the nostrils expand into a square shape. Normally, the nostrils are round when the horse takes a breath.

It is an important sign of pain, because it can be seen, even if the horse otherwise seems to be breathing normally.


When the horse is in pain, it tightens the muzzle so that it becomes more square in it – normally it is soft and rounded.

Other discoveries in the study on pain in horses

The horses in the experiment wanted to be with the researcher, even if they were in pain. It is different from previous research. Here, the horses have been more hesitant to interact with humans when they were in pain.

The difference is perhaps that in this experiment, the horses were trained before the study, and the researcher was a person they knew and associated with something positive.

It is worth noting. Because perhaps horses that feel in a safe environment seek more contact when they experience mild or acute pain.


Gleerup, KB, Forkman, B., Lindegaard, C., & Andersen, PH (2015). An equine pain face. Veterinary anesthesia and analgesia, 42(1), 103-114.