KAIRON
Digitalising the scientifically validated
Ridden Horse Pain Ethogram (RHpE) by Dr. Sue Dyson
Don't let them be misunderstood
Ride with a clear conscience
Kairon cannot comment on the psychological state of your equine partner. It can however give you a science-backed peace of mind regarding its physical state.
Optimise your performance
Kairon can make sure your horse is at its optimal shape when you get on it or when entering the show ring. Do not let pain or discomfort limit its performance.
Boost your finance
Detect discomfort before it escalates into actual lameness with the associated vet bills, impact on performance or selling price.
Founding Scientific Advisor
Dr. Sue Dyson
Veterinary Surgeon Inventor of the Ridden Horse pain Ethogram
World-reknown lameness expert Former President of the British Equine Veterinary Association

Kairon allows you to detect pain or discomfort that usually goes undetected
The Tech
Get your horse checked in 3 simple steps
Video
Film your horse being ridden at home by following our instructions and upload it on our platform
Analysis
Your video gets analysed by our AI algorithm and reviewed by a certified professional
Report
Receive a full report about how your horse is doing, including its RHpE score, with supporting material
I firmly believe Kairon has the potential to revolutionise the way we monitor horses well-being and performance. The emphasis on scientific rigor and user-friendliness perfectly matches the needs of equestrian professionals and riders.
Eugénie Cottereau
Ergonomie Equestre, France
This represents a revolution.
Dr. Xavier d'Ablon
Veterinary Surgeon, Clinique de la Côte Fleurie (Deauville, France)
An AI-powered app that applies the RHpE objectively is no less than revolutionary.
Sue Palmer
The Horse Physio, UK
Finally someone built this! The RHpE is revolutionary, but you need assistance from a robot to apply it correctly.
Hannah Knaebel
Saddle-fitter, USA
There is little doubt that Kairon will become the standard-setting tool for equine pain detection and management.
Dr. Camille Charron
Veterinary Surgeon, Clinique de la Côte Fleurie (Deauville, France)
Dr. Sue Dyson's findings are currenty shaking the horse world to its core.
Riverstown Farm stables
USA
I firmly believe Kairon has the potential to revolutionise the way we monitor horses well-being and performance. The emphasis on scientific rigor and user-friendliness perfectly matches the needs of equestrian professionals and riders.
Eugénie Cottereau
Ergonomie Equestre, France
This represents a revolution.
Dr. Xavier d'Ablon
Veterinary Surgeon, Clinique de la Côte Fleurie (Deauville, France)
An AI-powered app that applies the RHpE objectively is no less than revolutionary.
Sue Palmer
The Horse Physio, UK
Finally someone built this! The RHpE is revolutionary, but you need assistance from a robot to apply it correctly.
Hannah Knaebel
Saddle-fitter, USA
There is little doubt that Kairon will become the standard-setting tool for equine pain detection and management.
Dr. Camille Charron
Veterinary Surgeon, Clinique de la Côte Fleurie (Deauville, France)
Dr. Sue Dyson's findings are currenty shaking the horse world to its core.
Riverstown Farm stables
USA
Use cases
Example situations in which Kairon can bring you a peace of mind. Objectively.
Comfort assessment
Objectively evaluate whether your horse is expressing a form of discomfort or pain when under saddle. Use this baseline to monitor its evolution in time, or to objectivise the impact of a treatment or tack-change.
Pre-purchase examination
Evaluate objectively the level of comfort of a horse prior to purchasing it, and avoid future heart-ache if that horse develops signs of lameness, behavioural issues or reduced performance after purchasing it.
Revalidation monitoring
Kairon allows you to monitor the evolution of your horse during its revalidation period, to minimise the chances of relapse.
Crisis resolution
If you are encountering behavioural or performance problems with your horse, that you can feel something is off with it but your horse shows no sign of lameness, Kairon would able you to objectivise that feeling and to clarify whether it is pain-related or not.
Championship follow-up
Make sure your horse is in optimal shape in the weeks/months leading up to an important sport event. Rule the issue of discomfort of pain out of the prejudices that could negatively impact its performance on d-day.


RHpE Facts
The RhPE has been tested in scientific studies and on the field on thousands of horses.
A final score of 8 markers or more indicates the presence of underlying pain.
Most behavioural markers are 10 times more likely to be seen in a lame horse.
Studies have proven a significant correlation between RHpE scores and final placing in competitions.
Eventing horses showing >7 RHpE markers at warm-up were twice as likely to not finish the cross-country.
The Tool
The Ridden Horse Pain Ethogram
Your horse performance checklist
The only science‒based tool to objectivise your horse's level of discomfort.
3 Temporal Rules
Any horse can display a movement or action in isolation — this alone does not indicate pain.
But when such action persists or repeats over time, it becomes a 'behaviour'.
Extensive research by Dr. Sue Dyson and her team has demonstrated that the presence of multiple such behaviours—statistically, 8 or more out of 24—makes the presence of underlying pain or discomfort near certain.
Timed events
The action must last a certain number of seconds
Repeated events
The action must be seen more than once
Trot pace
You should count a certain number of strides over a temporal segment
5 Focus Areas
The 24 Behaviours
Each of the 24 behaviours meets a strict, objective and measurable definition.
Facial expressions
1. Sclera exposed
The white of the eye is apparent. Observed 2 times or more.
2. Mouth opening
The mouth is opened with separation of the teeth. Observed repeatedly over a 10 seconds segment.
3. Tongue
The tongue is apparent and/or out of the oral cavity. Observed 2 times or more.
4. Bit pulled
The bit is asymmetrical in the horse's mouth.
5. Intense stare
A glazed expression, the eye looks not engaged, the horse seems "zoned out". Observed for 10 seconds or more.
6. Eyelid
Eyelid held closed or half-closed for 2-5 seconds.
7. Ears back
One ear or both are rotated backward or flat. Observed for 5 seconds or more.
Head position
8. Head tilt
Head tilting to one side. A line between the tip of the nose and between the ears is not vertical.
9. Lateral head movements
Head moving from right to left without being induced by the rider's hand. The head is tossed or twisted from side to side, needs to be corrected constantly.
10. Head movements
Head moving up and down, not in rhythm with the trot.

11. Head behind the vertical
The head is held 10° or more behind the vertical for 10 seconds or more.
12. Head in front of the vertical
The head is held 30° or more in front of the vertical for 10 seconds or more.
Hind area
13. Tail swishing
The tail is swishing large movements, up & down, side to side or in circular movements, two times or more.
14. Tail position
The tail is held to one side or clamped (held tightly to the middle).
15. Moving on 3 tracks
The hindlimbs do not follow the tracks of the forelimbs, making the horse moving on 3 (or 4) tracks in trot or canter. The hindlimbs repeatedly deviate to left or right on a straight line.
Gait abnormalities
16. Tripping, stumbling, toe drag
The horse trips or stumbles two times or more. The tip of the hoof touches the ground as they bring their leg forward ("toe drag") two times or more.
17. Canter dysfunction
Four different canter abnormalities can be identified. They must be seen twice or more. 1. Unrequested flying change, 2. Repeated leg change in front and/or behind, 3. Strike off on the wrong leg, 4. Cantering disunited.
18. Unrequested change of gait
Spontaneous change of gait, without a rider's cue - e.g. breaking from canter to trot, or from trot to canter.
19. A rushed gait
The frequency of trot steps is over 40 strides over a 15 seconds segment.
20. Gait too slow
The frequency of trot steps is below 35 strides over a 15 seconds segment. "Passage-like" trot.
Whole-horse behaviours
21. Spooking, unrequested change of direction
The horse 'spooks' or changes direction spontaneously, against the rider's cue, two times or more.
22. Rearing
The horse lifts both forelimbs off the ground.
23. Bucking or kicking backwards
The horse lifts both hindlimbs off the ground or kicks to the side.
24. Reluctance to move forward
The horse is "dead to the leg" (you can verbally ask the rider), needs verbal encouragement to move forward. The horse stops spontaneously.
Kairon's mission:
scaling the usage of the revolutionary RHPE
Speed
Let our AI analyse the video for you in just a few instant. Quickly get an idea about your horse's level of comfort.
Precision
Make sure your eye does not miss any subtle mouvement or marker when a lot happens rapidly and simultaneously in your video.
Objectivity
Access an AI model trained on the industry's gold standard: Dr. Sue Dyson's eye.
See Kairon like a warning sign that lights up on your dashboard.
Kairon is not a diagnostic tool. It is a horse's only way to communicate its pain or discomfort. Used in conjunction with nerve blocs, it can help locate the source and area of pain and thus establish a diagnosis.
Check Your Horse
Don't let them be misunderstood
Have your horse checked by a trained professional from a video using the Ridden Horse pain Ethogram.
AI
Advisory Board
We have gathered the best minds to help build the best functioning technology.
Laboratoire du GREYC
Equipe 'Image'
Testimonials & case studies
Show Jumper, 5-year-old French Warmblood "Isaure felt tense in the contact, tripped a lot, and just wasn’t progressing like a normal 5-year-old. Four vets told me she was sound after a classical lameness work-up. But the RHpE scored her 13/24, which justified to do X-rays —which revealed cervical arthritis and mild ataxia. This wouls have 100% gone unnoticed without using the RHpE!"
Margot
Rider
Retired Thoroughbred, Leisure Horse
"He looked great and felt fine most of the time, but under saddle I just had a weird feeling. The RHpE scored him 10/24. A gastroscopy found severe ulcers. After treatment, his score dropped to 3/24 and he rides like a new horse. It confirmed I should always listen to my instincts, and the RHpE confirmed my feeling."
Sophie
Leisure rider
Hanoverian Eventer, 12 years old
"He was competing in eventing, passing vet checks, and moving symmetrically, but I could feel something was off. The RHpE gave him a 9/24. X-rays revealed navicular disease in both front feet—no limp, but still very painful. Without the RHpE, I would still be asking him to do cross-country, putting us both at risk..."
Camille
International eventing rider
Pre-Purchase Exam Case
"The vet passed him on a pre-purchase exam, but RHpE scored 9/24. I bought him anyway. Less than a year later he went lame from a hind suspensory injury, caused by a long-standing back problem the standard exam had missed. The RHpE could have saved me a lot of heartache."
Julien
International show jumping rider
Leisure Mare, 6 years old
"She was sweet but could explode violently in certain exercises. RHpE scored her 12/24, so we investigated further. X-rays revealed a fractured occiput—she needed surgery. Now she’s back under saddle, calm, and happy. I wish I’d known about the RHpE earlier!"
Marta
Leisure Rider
Dressage Horse, Grand Prix level
"He started feeling crooked in the contact and bend, though he seemed sound! RHpE scored him 8/24. Diagnostic imaging revealed an early hind suspensory injury—treatable before it caused limping. Now he feels straight again and has moved up to 3* Grand Prix level, breaking his personal record!"
Elise
International dressage rider
Key Scientific Studies
The Ridden Horse pain Ethogram is currently the only scientifically backed tool to detect pain in ridden horses. It has been developped and used in multiple rigorous scientific peer-reviewed studies.
FAQ
My horse shows no sign of lameness in hand.
There is clear evidence that many horses are apparently sound in hand, even after flexion tests, and also trotting in a small circle on a soft or firm surface, and yet they show pain when they are ridden, manifest as performance problems for the riders. (Dyson & Palmer, Harmonious horsemanship, 2023)
A 2021 study of 148 horses, revealed that while “28% were lame in hand, (...) 62% were lame ridden”. Being assessed in hand or tacked up, with the weight of a rider and performing demanding movements, are two very different efforts. Moreover, lameness is often so low level that it is hard to see for the human eye. Compensatory patterns of your horse’s mouvement can also mask the lameness. A horse may be lame on more than one limb. Limping on the two same-sided legs or in diagonal makes the horse still move symmetrically, making classical lameness assessment nearly irrelevant. This is why behavioural assessment is critical to detect pain in ridden horses.
My horse is just grumpy and has always been.
We have traditionally labelled horses displaying behavioural signs of pain as “moody” or “naughty”. But research conducted on hundreds of horses clearly shows a significant correlation and causation link between the 24 markers and the presence of underlying pain. Your horse is probably trying to communicate its discomfort to you, do not let them be misunderstood.
The rider is inexperienced, a professional rider would have the horse behave better.
Studies have shown that, “no significant difference in the number of behaviours shown between the normal rider and the professional rider were observed, but some of the behaviours changed. For example, a horse may change from the front of the head being in front of the vertical, to behind the vertical once a professional rider gets on.
It was concluded that rider skill could not overcome the behavioural signs of discomfort, although a more skilled rider could improve gait quality and, in some horses, conceal lameness” (Sye Dyson & Sue Palmer, Harmonious horsemanship, 2023).
I will just “ride him/her through it” and the markers will disappear.
We recommend you to thoroughly apply the “2-weeks rule” : “It is not alarming for some markers to appear with new exercises or for horse not fit enough/in shape for what is asked. However, if the markers persist after 14 days of learning the new exercice, it is then a clear sign of underlying pain.” (Sue Palmer & Sue Dyson, Harmonious horsemanship, 2023).
My horse is young and untrained.
“Assuming a horse is not in pain, we would not expect it to show >8 of the 24 markers. A young horse may misunderstand a cue and react against it, have a unsteady head carriage, not easily go in a straight line, open the mouth when asked for a downwards transition, but we we would not expect it to have its mouth open with separation of the teeth for >10s. The front of the head may be in front of the vertical, but not >30°. It may be worried by the rider’s weight and accelerate or buck, it may lay its ears back, but not persistently.” (Dyson & Palmer, Harmonious horsemanship, 2023).
What if my score remains >8 after resolution of pain? Are there any of the RhPE behaviours which are less likely to change after resolution of pain?
“Failure to substantially reduce the RhPE score after resolution of lameness means that there must be another source of pain. Consider oral pain, thoracolumbar pain (either primary, or secondary to an ill-fitting saddle or inappropriate distribution of the rider’s weight), or lumbosacroiliac joint region pain, or neck pain.”(Dyson & Palmer, Harmonious horsemanship, 2023)
This is one of the key strengths of the RHpE and what makes it so revolutionary: it is the complete eradication of pain that now guides veterinary investigation, and we are now able to keep on investigating and treating until the horse stops communicating its pain or discomfort.
I am still unsure whether my horse's bad behaviour is due to pain or not.
In such case, treating the horse with a pain-relieving drug, such as phenylbutazone can help determine if there is underlying pain - although it may not relieve all possible forms/sources of pain.
However, a positive response (improvement in performance - a lower RHpE score /24) indicates the presence of musculoskeletal pain, but a negative response does not preclude the presence of such pain because phenylbutazone does not alleviate all sorts of pain.
We generally advise keeping a diary of the horse's daily RHpE score for a week before treatment, during the week of treatment and for at least a week after stopping treatment. An RHpE score going down during treatment or going up after stopping treatment indicates the likely presence of pain.
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