Do Handling and Transport Stress Influence Adrenocortical Response in the Tortoises (Testudo hermanni)?

The goal of this study was to analyze circulating cortisol levels from tortoises (Testudo hermanni) to establish reference intervals and to develop guidelines for the interpretation of the effect of handling and transport stress. Blood samples were obtained from the caudal venous from 23 healthy juvenile tortoises (9 males and 14 females), aged 8–20 years, in basal condition, four weeks prior to and four weeks following handling and short transportation. The study was carried out on the experimental group: 10 tortoises, 4 males and 6 females, and on a control group: 13 tortoises, 5 males and 8 females. Compared to basal values, circulating cortisol concentrations was higher after handling and transport (+286%; ), with an increase of +246% ( ) in males, +236% ( ) in females, +370% ( ) in subjects aged 8–12 years, and +240% ( ) in subjects aged 13–20？years. These observations support the hypotheses that cortisol may act to mediate the effects of handling and transport stress in this species and that four weeks following handling and transport were insufficient to restore their homeostasis. 1. Introduction Many endocrine responses in tortoises are very similar to those of other reptiles, even if they also show some specific aspects [1]. Several reptiles, including sea turtles and tortoises, are known to modify their stress response according to their body condition and analysis of blood constituents is useful in the diagnosis of health and disease status [2, 3] and has helped to identify stressed or ill tortoises [4–6]. Previous studies have described the effects of external and internal factors on the capacity of individuals to induce different physiological coping strategies in response to stressors. Changes of animal homeostasis induce a hormonal response that results in an increase of glucocorticoids, catecholamines, and other blood factors [7–9], necessary to restore their homeostasis. Factors, such as disease and body condition, have been associated with significant changes in plasma corticosterone [10–13]. Measurement of plasma cortisol values is commonly used as a diagnostic technique to assess welfare or stress conditions of individual animals [14, 15]. However, there appears to be fragmentary information on reference intervals and physiological alterations in hormonal values in tortoises [16, 17] and in free-ranging desert tortoises [18]. In the last years the clinic reports, as repair and dressing of fractures, surgeries, shell diseases, and mycoplasmosis, related to cases suffered by Chelonia, were scarce and inadequate [19, 20]. Moreover,