Differences in the capture stress response between captive and free-ranging roe deer (Capreolus capreolus) and its modulation by acepromazine

This study examined the differences in the capture stress response between captive and freeranging roe deer (Capreolus capreolus) and its modulation by acepromazine over a threehour period following the capture operation. We captured 32 roe deer (16 free-ranging and 16 captive) using drive-nets. These two groups were further divided into two sub-groups: animals in the treatment group received an intramuscular injection of acepromazine (n = 8 free-ranging and 8 captives) whereas animals in the control group received the same volume of saline (n = 8 free-ranging and 8 captives). Heart rate and body temperature decreased over time (P < 0.05) after capture in all four groups. However, heart rate stabilised sooner in the treated roe deer than in the controls, whereas body temperature stabilised sooner in the free-ranging roe deer than in the captives. Red blood cell (RBC) count and haemoglobin concentration decreased over time in the treated deer, were significantly lower in the treated group than in the control one in both free-ranging and captive animals, and were also lower in free-ranging animals than in captives (P < 0.01). Packed cell volume (PCV) was lower (P < 0.01) in the treated deer than in the controls in both free-ranging and captive animals. Lymphocyte count decreased over time in all groups except for free-ranging treated animals (P < 0.001). Leukocyte and neutrophil counts did not differ significantly among groups, showing a significant increase over time (P < 0.01). Serum creatine kinase (CK), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) activities, and serum creatinine and urea concentrations increased significantly over time (P < 0.01) in control captive animals. Serum AST activity also increased over time in control free-ranging animals (P < 0.01). Serum CK, AST, ALT and LDH activities, and serum creatinine were significantly higher in captive control animals than in captive treated ones and free-ranging controls. Serum lactate concentrations decreased over time in all four groups (P < 0.001). Just after capture, lactate levels were higher in captive animals than in the free-ranging ones (P = 0.0001). However, one hour after capture lactate levels were lower in treated animals, regardless of whether they were captive or free-ranging (P < 0.01). Cholesterol and glucose concentrations were significantly higher (P < 0.01) in captive animals in comparison with the free-ranging ones. Moreover, serum glucose concentrations began to decrease one hour after capture (P < 0.01) in captive animals in both the treated and the control groups, although they were significantly lower in those that received acepromazine. Serum potassium levels decreased over time only in the control groups (P < 0.01). No differences were observed in serum cortisol levels. These results show the beneficial effect of using acepromazine to prevent capture myopathy in physical capture operations, especially in captive roe deer, and a differential stress response between captive and freeranging animals, which should be considered when capturing and handling roe deer.