The Ridden Horse Pain Ethogram (RHPE) is a comprehensive tool used by equine professionals to identify musculoskeletal pain in horses while being ridden. It consists of a list of 24 behaviors associated with pain and discomfort in horses under saddle.

Dr. Sue Dyson developed this ethogram as a means of identifying low-grade lameness and discomfort in horses during ridden work. Early identification of lameness can improve horse welfare by enabling medical treatment prior to overt lameness.

To complete this evaluation, the horse is observed over a 5–10-minute period, with the evaluators looking for the 24 behaviors described in the RHPE. Horses that display 8 or more of the behaviors are likely to have musculoskeletal pain.

Studies show that the RHPE can successfully distinguish between lame and non-lame horses under saddle and can predict performance in dressage and eventing competitions.

Other applications of the RHPE include use during pre-purchase examinations to identify low-grade lameness. The ethogram may also help riders and saddle fitters identify poor saddle fit in horses experiencing pain from their tack.

What is an Ethogram?

An ethogram is a systematic list of behaviors performed by a particular animal species. [1] It catalogs the various actions, movements, and responses observed in the natural behavior repertoire of the animal.

Ethograms are used in ethology, the scientific study of animal behavior, to document and analyze behavioral patterns, social interactions, communication signals, and other aspects of animal behavior.

Most ethograms catalogue behaviors displayed by a species during a particular scenario, such as maternal interaction with their offspring. [2]

Studying behavior requires observation of the animal and interpretation of their actions, which is often subjective. [3]

Researchers and veterinarians use ethograms as a way of objectively measuring an animal’s behavior for scientific purposes. [3] Objective measurement minimizes the risk of subjectivity and increases the validity of scientific studies, making their findings more impactful. [3]

Equine Ethograms

In horses, there are several ethograms available for different scenarios. There is also a comprehensive catalogue that aims to describe all known behaviors of equids, so that researchers can use these descriptions as a starting point for their own ethograms. [2]

Equine ethograms currently exist for: [2][4][5]

  • “Maintenance behaviors” such as eating, drinking, and seeking shelter
  • Social communication
  • Interaction between males
  • Reproductive behaviors
  • Play behaviors
  • Pain and discomfort
  • Stereotypies such as cribbing, weaving, and wood chewing

Creation of an Ethogram

Ethograms are particularly impactful in veterinary medicine, as veterinary patients cannot speak to describe the pain or discomfort they are experiencing. For this reason, researchers are developing ethograms to objectively identify behaviors associated with pain in animal species.

Objective identification of pain behavior improves animal welfare by indicating a need for prompt medical intervention. [1]

To start making an ethogram, researchers select a list of behaviors to include. [6] These behaviors must have detailed, specific descriptions that allow observers to make an objective judgment as to whether the behavior is present. [3]

Ideally, researchers developing the ethogram will perform a study confirming that the descriptions are comprehensive, understandable, and have a high degree of agreement between observers. [6]

After establishing the behavior list, many researchers use the Delphi technique to finesse the ethogram model. [6] The Delphi technique involves consulting numerous experts and having them weigh in on the behavior list, ranking the behaviors based on their interpretation of the each one’s significance. [6]

The researchers then calculate the most significant behaviors using the rankings established according to the Delphi technique. [6] The final ethogram is then subjected to validation studies, where the researchers apply the ethogram to both healthy horses without known pain and horses expressing pain or discomfort. [6]

A successful ethogram will show a significantly higher behavior score for horses expressing pain or discomfort, indicating its validity as a diagnostic tool. [6]

The Ridden Horse Pain Ethogram

The Ridden Horse Pain Ethogram (RHPE) is an ethogram developed by Dr. Sue Dyson et al., with the goal of identifying behaviors associated with musculoskeletal pain in horses under saddle. [1] Veterinarians, researchers, and equestrians can use the RHPE as a method for diagnosing low-grade lameness in performance horses. [1]

Many studies using the RHPE currently focus on welfare evaluations of horses performing at competitive events, to examine whether horses are fit and sound enough to compete. Current studies show a correlation between RHPE score and performance in dressage and eventing, with horses that have lower RHPE scores placing higher in competition.

Although the RHPE has several validation studies in English discipline horses, further research is necessary to finesse the RHPE and ensure its validity across disciplines and groups of horses.

Development of the RHPE

The initial behavior list for the RHPE included 117 behaviors previously described as indicators of conflict or pain in horses. [1][7] An experienced reviewer observed videos of 9 horses, both lame and non-lame, and identified whether each of the 117 behaviors occurred during the video. [7]