The significance of dermatoglyphic characteristics in the determination of equine phenotypic susceptibility to abnormal repetitive behaviour in the thoroughbred (Equus caballus)

Abstract

Background: Relationships have been established between trichoglyphs (whorls) and temperament, laterality and the occurrence of abnormal behaviour in multiple species. Within the equine industry stereotypic behaviour is considered to impair performance and reduce value in affected individuals, potentially reducing career longevity and compromising welfare through preventing their expression when they occur. Aim: The study aimed to determine whether dermatoglyph profiles (whorl morphology, orientation, number and topography) could be used to predict susceptibility to perform abnormal repetitive behaviours (ARB) in thoroughbred racehorses. Method: Trainer interviews combined with experimenter direct observation were used to ascertain expression of ARBs. Whorls were digitally photographed and overall whorl profiles derived using remote computer analysis. Results: Non-parametric statistical analysis revealed significant relationships between aspects of whorl morphology and performance of ARBs (round epicentre: sum ARBs p<0.05; round gross morphology: sum ARBs p<0.0001), orientation and distribution (abdominal trichoglyph orientation asymmetry: sum ARBs p<0.05; clockwise orientation: sum ARBs p<0.05 and social stereotypies p<0.05). Conclusion: This study indicates that whorls may be viable physical indicators of predisposition to perform ARBs in the thoroughbred. Assessment of dermatoglyph profiles have potential to assist with the improvement of horse welfare via informed management practices if patterns exposed are transferable to other breeds and can reliably predict individuals with a propensity to develop ARBs.