AUTHOR=Briefer Freymond Sabrina , Bardou Déborah , Beuret Sandrine , Bachmann Iris , Zuberbühler Klaus , Briefer Elodie F. TITLE=Elevated Sensitivity to Tactile Stimuli in Stereotypic Horses JOURNAL=Frontiers in Veterinary Science VOLUME=6 YEAR=2019 URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2019.00162 DOI=10.3389/fvets.2019.00162 ISSN=2297-1769 ABSTRACT=

Although stereotypic behaviors are a common problem in captive animals, why certain individuals are more prone to develop them remains elusive. In horses, individuals show considerable differences in how they perceive and react to external events, suggesting that this may partially account for the emergence of stereotypies in this species. In this study, we focused on crib-biting, the most common stereotypy displayed by horses. We compared how established crib-biters (“CB” = 19) and normal controls (“C” = 18) differed in response to a standard “personality” assessment test battery, i.e., reactivity to humans, tactile sensitivity, social reactivity, locomotor activity, and curiosity vs. fearfulness (both in novel and suddenness situations). Our analyses showed that crib-biters only differed from control horses in their tactile sensitivity, suggesting an elevated sensitivity to tactile stimuli. We suggest that this higher tactile sensitivity could be due to altered dopamine or endogenous opioid physiology, resulting from chronic stress exposition. We discuss these findings in relation to the hypothesis that there may be a genetic predisposition for stereotypic behavior in horses, and in relation to current animal husbandry and management practices.