The Horse Physio - Delivering care with expertise since 1992

15.5.2022: The Ridden Horse Pain Ethogram – Research and Development

Recognising Your Horse’s Pain Face

Thirteen people from different equestrian backgrounds were trained to look at photographs of horse’s heads and pick out specific features. They had a list of what they were looking for (an ethogram of ridden horse facial expressions), and had to mark each item as yes, no, or cannot see. Once they’d undergone the training, these people looked at 30 photographs of horses, some of which were lame and some of which were not lame. Overall, there was 87% agreement on the findings, with 2 of the 13 assessors consistently scoring differently from the other 11. The features that there was least agreement on were to do with the eyes and the muzzle. The study concluded that the ethogram could be reliably used to describe the facial expressions of ridden horses, but that more work was needed to find out if this could be a way of sorting lame from non-lame horses.

Mullard, Jessica & Berger, Jeannine & Ellis, Andrea & Dyson, Sue. (2016). Development of an ethogram to describe facial expressions in ridden horses (FEReq). Journal of Veterinary Behavior: Clinical Applications and Research. 18. 10.1016/j.jveb.2016.11.005

You can access this article here.


Many horses presumed to be sound by their riders are not. Facial expression ethograms have previously been used to describe pain-related behavior in horses, but there is a need for a ridden horse facial ethogram to facilitate identification of pain in ridden horses. The objectives of this study were to develop and test an ethogram to describe facial expressions in ridden horses and to determine whether individuals could interpret and correctly apply the ethogram, with consistency among assessors. An ethogram was developed by reference to previous publications and photographs of 150 lame and non-lame ridden horses. A training manual was created. Thirteen assessors (veterinarians of variable experience, n=4; equine technicians, n=3; equine studies graduates, n=2; amateur horse owners, n=2; equine veterinary nurse, n=1; a British Horse Society Instructor, n=1) underwent a training session and, with reference to the training manual, evaluated still lateral photographs of 27 Training heads. Features were graded as Yes, No or ‘Cannot see’ (when it was not possible to determine the presence or absence of a feature). The ethogram was adapted and, after further training, the assessors blindly evaluated 30 Test heads from non-lame and lame horses. Intra-class correlation (ICC) and free-margin Kappa tests were used to assess consensus among assessors. For the Training heads, single ICC matrix among observers resulted in an overall ICC of 0.50 (95% Confidence Intervals CI, 0.40-0.62). Four assessors consistently scored differently from the others, with ranges of ICC of 0.20-0.50 (mean 0.41). There was no difference in assessors’ scoring related to their professional backgrounds. For the Test heads, mean inter-rater agreement among assessors was 87%. Two assessors still scored consistently differently (0.28-0.50 ICC agreement; mean 0.40) from the remaining 11 assessors (0.44-0.69 ICC agreement; mean 0.56). The mean percentage of overall agreement was 80% and the mean free-marginal Kappa value was 0.72, standard deviation (SD) ± 0.22. The large SD was the result of inconsistency in assessments of the eyes and muzzle. It was concluded that the developed ethogram could reliably be utilised to describe facial expressions of ridden horses by people from different professional backgrounds. Future work needs to determine if non-lame and lame horses can be differentiated based on application of the ethogram.

Dr Sue Dyson and I are in the process of writing a book for horse owners and riders on how to understand and use the Ridden Horse Pain Ethogram with your own horse. The book will be published by J A Allen, and available sometime In 2023. Sign up to my newsletter at for updates.

In the meantime, you will find my blog on how to use the RHpE with your own horse here. You can learn more about the Ridden Horse Pain Ethogram through listening to Dr Sue Dyson explaining here it on the Equine Veterinary Education, where you can also listen to her discussing many of the other studies that she has been involved in. You can also take an online course with Equitopia.

© Sue Palmer, The Horse Physio 2021

Treating your horse with care, connection, curiosity and compassion

May 15, 2022
Sue Palmer