Predisposing markers for diagnosis of elephant endotheliotropic herpesvirus-hemorrhagic disease and other illness conditions

Abstract

The Asian elephant (Elephas maximus) serves as a keystone species, playing a crucial role in wildlife-based ecotourism in Thailand. Captive elephants, mostly privately owned and residing in tourist-oriented facilities known as "elephant camps" across Thailand, have the potential to significantly impact elephant welfare and health due to diverse management styles and activities. Various diseases afflict captive elephants, including gastrointestinal issues, lameness, eye problems, and the deadliest ailment in calves: elephant endotheliotropic herpesvirus-hemorrhagic disease (EEHV-HD). These diseases pose a global threat to elephant conservation efforts. This study delves into biomarkers linked to oxidative stress and abnormal coagulation condition in elephants, taking into account both internal factors (age, sex, and health condition) and external factors (season and the temperature-humidity index). The findings underscore the correlation between age, season, and shifts in oxidative stress markers, emphasizing the importance of considering these factors during data analysis. Additionally, the health condition of elephants exerts an impact on their oxidative status, particularly noticeable in calves afflicted with acute EEHV-HD. These calves exhibited significantly elevated concentrations of malondialdehyde, glutathione peroxidase, and catalase, along with reduced serum albumin levels when compared to their healthy counterparts. However, the association between changes in oxidative stress markers and the salivary shedding of elephant endotheliotropic herpesvirus (EEHV) remains uncertain when longitudinally monitored, possibly owing to the limited number of shedding events during the study. As for coagulation markers, calves with acute EEHV-HD displayed prolonged prothrombin and activated partial thromboplastin times, and the lowest platelet count among various illness conditions, suggesting a pathological mechanism of this virus involving both intrinsic and extrinsic coagulation pathways. Results suggest the potential utility of this biomarker in predicting and monitoring elephant diseases. The study contributes valuable insights into the alterations in oxidative stress and coagulation biomarkers, shedding light on the pathophysiology of elephant ailments. Consequently, the findings can be applied within veterinary practice as an additional analytical tool for assessing and monitoring elephant health conditions, as well as a prognostic tool for ailing elephants. Future studies should explore how these biomarkers evolve in relation to other variables, such as management practices, dietary factors, activities, social dynamics, and various environmental influences.