Assessment of horses’ welfare: behavioural, hormonal and husbandry aspects

Horse practitioners have difficulties with undesirable behaviors exhibited by their horses ( Equus caballus ), such as cribbing, weaving, or head shaking. It has been suggested that most of behavioral disorders orig- inate from the animals’ attempt to cope with a suboptimal environment. To evaluate animal welfare, it is important to consider both behavioral and physiological parameters. Studies on animal welfare underline the importance of the monitoring of hormonal concentrations, particularly hormones that indicate stress, such as cortisol. The aims of this research were to compare cortisol and dehydroepiandrosterone (DHEA) concentrations of 14 healthy horses (HH) and 40 horses displaying behavioral pathologies (BPHs), to cal- culate the cortisol-DHEA ratio as marker of chronic stress and to find a relationship between aspects of horses management and the presence of BPHs. The methodology of radio-immuno-assay was used, to de- termine cortisol and DHEA levels in blood and hair. A questionnaire was completed by horse owners or barn managers and used to investigate the different characteristics of boarding barns, where the horses were housed. BPH horses registered a significantly ( P < 0.05) higher plasma cortisol/DHEA ratio value than HH horses. It is possible that BPH horses suffer chronic stress, which might cause a dysfunction of hypothalamic-pituitary-adrenal. A positive correlation was found ( P < 0.05) between the presence of BPH, time spent in stall and the frequency of work. Moreover, a low fiber, high-energy diet appeared to contribute to the development of BPHs. This study underlines the importance of a multidisciplinary approach to the evaluation of horse welfare. The improvement of welfare is closely correlated to a de- creased risk of the development of stereotypic or undesirable behaviors, and a better understanding of equine ethological needs is fundamental to advances in this area.