The Animal Health Trust (AHT), in Newmarket, U.K., is celebrating the anniversary of one of its most valued staff members, Sue Dyson, MA, Vet MB, PhD, DEO, FRCVS, with the release of her latest results from her ongoing equine facial expressions and behavior study.

As Head of Clinical Orthopaedics at the AHT, Dyson has dedicated 35 years to treating hundreds of patients each year in the clinic, as well as advancing the knowledge and techniques in equine medicine through her research. With a strong background as a rider and a particular interest in lameness and poor performance in sport horses, she has an in-depth knowledge and understanding of performance problems in horses of all disciplines.

Dyson’s ongoing study is aimed at improving our collective understanding of pain in equine athletes. She is developing a method by which owners, trainers, and equine professionals can recognize pain in their horses when they are ridden by assessing facial expression and behavior.

This study evolved from her clinical work, in which she recognized that too often poor performance has been labelled as “naughty” behavior or training problems rather than pain. As a result, cases are referred to her too late when injuries have become chronic, so problems are well developed and the opportunity for recovery is compromised.

The third of four stages in this project has been completed; this stage involves developing a visual aid for identifying pain and/or lameness by assessing the horse as a whole, building on the success of facial expressions being a proven indicator. In addition to facial expressions, behavioral markers of pain included head tossing, unwillingness to go forwards, hurrying, toe dragging, crookedness, changing gaits spontaneously, and stumbling.

Lame horses had substantially higher behavioral scores than non-lame horses. Dyson identified 24 key behavioral markers and determined that the presence of eight or more was likely to signify musculoskeletal pain.

She considers it important to assess horses both in trot and canter, because some horses show more signs reflecting discomfort in one gait compared with the other. It was equally important to assess horses performing movements requiring more collection, when applicable, because it could only be when more physical demands are placed upon the horse that signs reflecting pain become apparent. Being able to detect pain as early as possible using this visual guide and scoring system enables quick reactions, so that whatever is causing the horse pain (tack or injury) can be rectified, which greatly increases the horse’s chances of a successful outcome.

Dyson continues to investigate equine health and welfare, inspired by the resilience of equine athletes; she still works tirelessly to improve their care for years to come, sharing her knowledge with the equine industry and owners to put into practice.

“I owe a huge debt of gratitude, not only to the friends and colleagues I’ve had the privilege to work with, most particularly at the AHT, but also to the horses, which provide endless challenges” she said. “Our clinical cases are integral to our research. Without them and the willingness of their owners to contribute their data to our research projects, we would not be able to advance veterinary techniques as comprehensively as we do now. At the AHT we have developed a cycle, whereby our clinical patients feed into our research, and in turn our research results are fed back into the industry to develop veterinary and owner knowledge to support the care of horses worldwide.

“I have always had a thirst for new knowledge and quickly learnt that by documenting my clinical observations, certain patterns emerged which could be translated into recognizing new conditions,” she added. “I didn’t think of this as research—just learning on the job. There are many unanswered questions when it comes to horses, and the learning process proceeds endlessly—and excitingly!”

Stage 3 of the ongoing project, “Development of an ethogram for a pain scoring system in ridden horses and its application to determine the presence of musculoskeletal pain,” was published in the Journal of Veterinary Behavior: Clinical Applications and Research and can be viewed in full online.