Seasonal patterns of oxidative stress markers in captive Asian elephants in Thailand and relationships to elephant endotheliotropic herpesvirus shedding

Introduction Oxidative stress refers to an imbalance between oxidant and antioxidant activity accumulation of reactive oxygen species, which can have detrimental effects on animal health. Annual fluctuations in oxidative status occur, increasing disease susceptibility during certain time periods. However, a full understanding factors related Asian elephants how mitigate the negative consequences is lacking. Methods This study measured six serum markers [reactive species (ROS), malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), albumin, glutathione peroxidase (GPx), catalase] two [serum cortisol fecal glucocorticoid metabolites (fGCM)] 23 captive Thailand over 12 months period examine relationships with age season. Results Seasonal variations were observed, several exhibiting significantly higher concentrations summer (ROS, MDA, 8-OHdG, albumin) lower values rainy/winter seasons (MDA, catalase). By contrast, GPx was only marker be highest rainy For markers, fGCM noted season, contrasts earlier studies showing more winter (tourist season). Positive correlations found temperature-humidity index ROS, GPx, fGCM, while correlation observed albumin. Elephant endotheliotropic herpesvirus (EEHV) shedding events associated ROS MDA. A moderate 8-OHdG PCR threshold cycle EEHV (Ct), indicating DNA damage may involved elephants. Discussion revealed significant seasonal those should considered design data interpretation. There also physiological adaptations conditions relation environmental changes that could impact health outcomes.