Equestrian stakeholders lag behind the companion animal industry in emphasizing the importance of the human-animal bond, researchers suggest.
Human-horse interactions are central to our relationship with equines, but there appears to be little consensus around valid measures of their emotional state and reaction to human contact, they reported.
Katherine Kelly, Laurie McDuffee and Kimberly Mears, in a just-published scoping review, set out to examine the effects of human-horse interactions on equine behaviour, physiology and welfare.
The review team, writing in the journal Animals, said human-horse interactions are important, and stakeholders are invested in making sure that they are humane. Interactions are diverse, ranging from those with working horses through to pleasure or companionship.
“As a result, the welfare of horses during these interactions, including their mental and physical health, is an important consideration,” the trio said.
Although the physical health of horses can be readily measured during equestrian activities, their mental health is more difficult to assess.
The review was conducted to evaluate what is known about the horse’s mental state during common human-horse interactions in a bid to better understand their welfare.
They set out to map current practices related to the measurement of interactions, explore their known effects on horse behaviour and physiology, and clarify the connection between human-horse interactions and equine welfare.
A total of 45 articles met their criteria for inclusion in the review.
Studies that used both physiological and behavioural measures of equine response to human interactions accounted for 42% of the included studies. A further 31% exclusively used physiological measures and 27% used behavioural observation.
The authors found that the current evidence of equine welfare during human-horse interactions is minimal and based largely on the absence of a negative underlying emotional state during imposed interactions.
Measurement practices employed in studies were varied and diverse in character. “To date, there appears to be little consensus regarding reliable and valid measures of horse emotional state and reaction to human interaction,” they said.
“The science of human-animal interaction is often criticized for lack of methodological rigor and use of standardized tools and its subsequent influence on animal welfare.”
Significant differences and various practices were identified in the studies examined in the review. This, they said, indicates a need for standardization in measurement and reporting to improve our understanding of the impact of human-horse interactions on equines. Further research employing standardized assessment and objective inquiry is required, they said.
The authors identified several gaps in the literature that need to be addressed. “Many of the studies in the current review attempted to measure stress and concluded that lack of stress, based on physiological and behavioural indicators, was an indication of good welfare during human-horse interactions.
“Although this is one component of welfare, positive experiences perceived by the animal are also an important aspect of animal welfare.”
Therefore, more robust evaluations of welfare, including measurements of the horse’s underlying emotional state during human-horse interactions, are warranted, they said.
A more comprehensive evaluation will likely require the combined use of current methods, along with the addition of new methods. These could include a catalogue of bonding-related behaviors and physiological measures of hormones related to well-being, such as oxytocin and serotonin. Studies using a cognitive bias approach also show promise toward understanding animal emotion, they said.
“An emphasis on methods that use both behavioural and physiological measures is necessary since behavioural responses to the environment can be suppressed.
“Horses with passive coping styles and horses who are well trained may not readily show behaviours indicative of stress or aversion.”
Further understanding of current methods is also important, they said. For example, cortisol concentrations can reflect arousal and excitement as well as physical activity. Measures of heart-rate variability, which reflect the parasympathetic and sympathetic aspects of the autonomic nervous system, are complex and require further knowledge.
Continued analysis of the relationship between behaviours and physiological measures may lead to clear biomarkers for measurements of stress and well-being, they suggest.
“An improved ability to assess the horse’s emotional state during human-horse interactions will require an expansion in the use and understanding of current research methods and discovery and implementation of new methods.
“Although this may be a difficult task, it will be critical in truly assessing horse welfare during horse-human interactions and proposing future improvements towards equine welfare in the equine industry.”
Ensuring the welfare of horses during human-horse interactions is vital to promoting positive and safe relationships between humans and horses across various settings.
The review team concluded that standardized approaches to measuring key aspects of welfare within the horse are needed to advance understanding of how interactions with humans affect equine welfare.
Research is essential to continue to advance our understanding of the underlying emotional states of horses, the findings of which could be used to help policymakers in the equine industry. “The practical application of knowledge gained through research needs to be addressed.”
Changes are apparent in the perception of animals by humans in the 21st century, they said.
“An emphasis on animals as companions and promotion of the human-animal bond is leading to positive changes for animals in society.
“While stakeholders in the companion animal industry are emphasizing the importance of the human-animal bond, stakeholders in the equine industry lag behind.
“Because horses do not live in the house with humans, they are not often considered a family member.
“However, promotion of horses as companions, rather than simply a mechanism for fun, may improve the attention to welfare.
“Many equestrians genuinely want a positive relationship with their horse,” they said. Therefore, informing horse owners, trainers, and coaches that every human-horse interaction has a considerable effect in either improving or worsening the human-animal bond could influence their behaviour.
“Providing equestrians with tools to measure the emotional state of the horse during various interactions will also be essential for better attention to welfare.
“To this end, future aims in research should also include development and implementation of methods that can be used by equine stakeholders, and leaders in the field of equine health and welfare should be early adopters in promoting the human-animal bond with equestrians and horses.”
The review team was Canadian-based. Kelly is with the University of New Brunswick Saint John; McDuffee is with the Atlantic Veterinary College in Charlottetown; and Mears is with the University of Prince Edward Island, also in Charlottetown.
Kelly, K.J.; McDuffee, L.A.; Mears, K. The Effect of Human–Horse Interactions on Equine Behaviour, Physiology, and Welfare: A Scoping Review. Animals 2021, 11, 2782. https://doi.org/10.3390/ani11102782