Could measuring the brain waves of horses have a place in welfare assessments?

Measuring the brain waves of horses shows promise as an objective tool for assessing welfare and stress in horses, according to researchers.

Scientists in Germany set out in a pilot study to determine whether electroencephalography (EEG) might be useful in this regard.

Nora de Camp and her colleagues, reporting in the open-access journal PeerJ, note that views on animal welfare are often based on emotions rather than scientific findings.

“The assessment of welfare and well-being of animals is sometimes made by how humans feel when they find animals in certain situations,” they wrote.

“We need adequate techniques for an objective measurement of animal welfare and associated physiological states.”

EEGs are promising in this regard, because of the objective data they provide.

The study team described an experiment involving three adult horses at the Free University of Berlin.

During six different days, the horses were recorded for a total of 30 minutes, first in a resting condition, and then in a stress situation, having been placed in an examination stand in anticipation of veterinary treatment.

EEG readings were taken throughout and the horses in each video were assessed on the scientifically validated Horse Grimace Scale for comparison.

The researchers reported that they were able to see differences in EEG activity between the stress and rest phases in the horses, which also corresponded with significant changes in the Horse Grimace Scale scores between the two emotional states.

“Our results indicate a change of network activity during stress in the region of the somatosensory cortex,” they reported.

The results, they said, suggest that EEGs might be a robust tool for the objective assessment of animal welfare and well-being.

It may prove useful to judge the brain states, as well as the comfort, of newborns or disabled persons who are unable to communicate actively.

The study team comprised de Camp, Mechthild Ladwig-Wiegard, Carola Geitner, Jürgen Bergeler and Christa Thöne-Reineke, all afiliated with the Free University of Berlin. De Camp and Bergeler are also affiliated with the Humboldt University of Berlin.

de Camp NV, Ladwig-Wiegard M, Geitner CIE, Bergeler J, Thöne-Reineke C. 2020. EEG based assessment of stress in horses: a pilot study. PeerJ 8:e8629 https://doi.org/10.7717/peerj.8629

The study, published under a Creative Commons License, can be read here.