The EquiFACS study has managed to determine and codify the facial movements of the equus caballus.
Conclusions of the study:
- There are 28 different muscular movements that can be observed in the horse's face.
Of which 17 are AUs and 11 are ADs.
- In addition, different signs have been identified that horses can show on their faces. These have been named "gross behavior codes" and do not fall within the total facial muscle movements.
Example: chewing, yawning, grooming, etc.
- When comparing it with the HumanFACS we see that, of the 28 movements that horses can do, there are 20 that are similar to those of humans, 14 of which are exactly the same.