CORRELATION BETWEEN PLASMA CORTISOL AND REACTIVITY IN FIVE HORSES

A plasma cortisol measurement and behavioral assessment of five horses was performed, to determine whether there was a correlation between plasma cortisol and their reactivity. A subjective emotionality survey for each horse was completed by the horse's owners and an objective novel stimulus reactivity test was performed. The horses reactions were used to calculate reactivity scores on a reactivity assessment sheet we specially designed. Concentration of plasma cortisol was also measured and reactions to the blood sampling were quantified. Associations were made between those different parameters. All five horses appeared to be hypo reactive and their cortisol levels were also very low. Behavioral assessed reactivity seemed to correlate directly with the plasma cortisol, all values showing a marked hypo reactivity in all horses. The data obtained provided evidence that low plasma cortisol is a good marker of reactivity in hypo reactive horses and also that the designed sheets for the assessment of objective and subjective reactivity may be used, in correlation with plasma cortisol as an assessment tool in the current practice.