PhD Thesis defense by Aránzazu Buendía Andrés at the VISAVET Centre of the Complutense University of Madrid

November 28^th, 2022

Currently, one of the main areas of the equine sector in Spain is the use of the horse for pleasure and sports competition purposes at equestrian centres1. The equine veterinary clinician develops an essential role in the health surveillance of these horses and one of the most frequent tools is the completion of clinical analysis. For the correct interpretation of these analysis, reference intervals, defined by the range of values of an analyte from a population with a defined health status, are necessary.

To date, the equine population living in equestrian centres at central Spain did not have defined reference intervals; thus, the main aim of the present thesis was the determination of reference intervals using two different statistical methods (Reference Value Advisor and @RISK) for twenty hematology parameters, twenty bioquemistry parameters and four oxidative stress markers – uric acid (UA), tiobarbituric acid reactive substances (TBARS), total antioxidant status (TAS), 8-hydroxi-2-deoxyguanosine (8OHdG) – in this equine population, as well as the comparison between the determined reference intervals and the published bibliography.

The parameters included in the study showed a complex net of associations among the parameters and also with physiological and management factors; therefore, a multivariate analysis was essential to establish the importance of the different associations. Results demonstrated the relevance of the breed type and the physical activity over analytical values in the horse, fact that should be taken into account by the equine veterinary clinicians for the correct interpretation of the clinical analysis.